Re: [time-nuts] Good (cheap) PIC chip choice for project?
On Sun, 26 May 2013 00:12:58 + li...@lazygranch.com wrote: If you go arm cortex A little note here: Arm Cortex are multiple families of processors for different uses. And they vary a lot! Cortex-M: This family is ment to replace the old ARM7TDMI chips that are so ubiquitous. They are microcontrollers optimized for low power consumption with still a lot of peripherals and enough computation power to do things that recently needed a much larger and power hungry chip. They usually are run with the application writtend directly for the bare metal, ie without an OS. Or at most with a very thin layer of an RTOS. This family currently splits into three types of cores: Cortex-M3: this is the wast majority of todays new Arm uC chips. General purpose, does fit for most of the projects that require an uC. Cortex-M4: an upgraded version of the M3 that can run at higher clocks (i've seen up to 180MHz) and contains a single precision floating point unit. Mainly thought for projects that need a little bit more computing power or those that would benefit from floating point arithmetic. Cortex-M0: This can be seen as a shrunk down version of the M3. It is optimized for lower power applications than the M3 and meant to replace the 16bit uCs with a more versatile and easier to code for 32bit uC. Cortex-A: This family are the so called application processors and are the replacement for the venerable ARM9 and ARM11 families. They are supposed to run Linux, QNX or something similar, and on top of that your application. These parts start from 500MHz clock and go to 1.5GHz, from single core to quad core. So you have a damn lot of computation power. The usual use case for those is to control a user interface on an LCD with touch screen, do complex network protocols and stuff like that. Anything you wouldnt want to code yourself but a modern OS provides you for free. Big disadvantage of those cores is, that they are only available in BGA cases (i've not yet seen one available in QFP, if you are limited to that, choose from an ARM9), hence you usually want to buy a board that contains such a processor including its power supply and basic peripherals. E.g. the beaglebone black. Cortex-R: This family goes also into the category of application processors, but are optimized for real time applications. I did not have the chance to have a deeper look into them, yet. Thus i cannot say much about them. and linux, you will need to make your code a service. You will want it to start up by itself and if for some reason it crashes, you will want it to restart itself. The buzzword is harden and the techniques vary depending on the distribution. The advantage of running within an OS is that you can do that easily. You don't have to rely on external components like watchdogs to catch you in case something goes wrong. Also debugging is a lot easier as you are working in user space instead of on bare metal. Unfortunately, this makes people to code more sloppy, and together with more code that is run on such systems, the application gets a lot more fragile. But if you keep writing clean code, such applications are as stable and hard as on microcontrollers. You should check the architecture of the system. I didn't realize many of these boards run the ethernet off the usb hub. My recollection is the a10 used by Allwinner does not do that. I think you mean the Raspberry Pi here. It's the only one i'm aware of that provides an ethernet interface on board, although it doesn't have an ethernet MAC on-chip. I especially want to point out here that the processor of the RPI was originally designed as a setop box processor. That's why it looks like a huge GPU with a tinsy CPU attached. It also explains the lack of documentation (everything is under NDA) and why the interfaces are so quirky. For most projects, i would advise against the use of the RPI unless you are building something that relies heavily on a GPU and needs little else. There are other, better boards to choose from that are in the same price range or even cheaper. Examples are the aformentioned beaglebone black (using an Ti AM3359), or the two olixino boards (one featuring a Freescale i.MX23 and the other an AllWinner A10). Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
John, for guys like us who grew up with basic, there is an excellent (compiled) pic basic from http://www.protonbasic.co.uk/ I had a look at c, but decided at my time of life I wanted to produce working projects not learn new (cryptic to me) languages so I stuck with what I was comfortable with. As others have already said, occasionally you may need a tight bit of assembler for critical things but otherwise the high-level languages are the way to go. Ken, vk7krj www.vk7krj.com On Sun, May 26, 2013 at 1:47 PM, johncr...@aol.com wrote: Nice topic. I learned at bit. One source of info on the PIC is a course book and programming kit, programmer, prototype board and components set up by the ARRL. www.arrl.org You get all the stuff you need to get going. Software and a integrated development environment is provided. All in one package. They also have a couple of new courses on the Raspberry PI and the Arduino. I got into the PIC course last summer, read the extensive course book and learned to program the things. Made lights blink - also made LCD say Hi Hottie to my wife. My only comments - 1. Nice course for a beginner - my roots are old and in BASIC and FORTRAN Still used today, on junker laptops. So it was fun go fool with assembly for while. 2. My impression is that the PICs are powerful if you do a lot with one, but there is a lot of work involved to get up the learning curve. 3. My conclusion is that my next venture - should it occur will be with an integrated product that I can program in high level, with good input and some display capability, because I just want to get on with the project, but then I am not making a production device. Others comments re the more complex boards appreciated and noted for future reference. -73 john k6iql - ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Follow-up question re: microcontroller families
Hi On May 25, 2013, at 11:26 PM, Herbert Poetzl herb...@13thfloor.at wrote: On Sat, May 25, 2013 at 09:26:02PM -0400, Bob Camp wrote: Hi I realize this is a bit like water torture - sorry about that. If I go to Microchip Direct and ask for a PIC 18F with two UARTS and two A/D's I get the PIC18F86J72 and PIC 18F87J72. To me the second one is the obvious winner. It's got twice the flash for next to nothing more money. 1-25 piece price is $6.04. Same search, 1 A/D, 4 UARTS, lowest cost this time. PIC18F65J94 is the winner. Lowest price package is $3.30 in 1-25 pieces. 4 UARTS are untypical for PICs and result in higher price as the device usually has more pins (which makes them more expensive) The ARM that the thread was looking at was a 6 UART / 4 A/D part. Thus the load up the UARTS. Also the starting point for all this did involve serial i/o. Are those some *very* arbitrary choices - you bet they are. They are random picks, and were not optimized to show any particular thing. Only to target an application that had some serial i/o and a bit of A/D involvement. Bottom line - not all PIC's are $1. once you start adding peripherals. For $6 over in ARM land, you can get a lot of chip. To be fair, my experience has been that you can do better in the PIC24 line once you start adding stuff. Searching the PIC24's is hard enough that my brief search tonight did not show up a lower cost part. PIC24F04KA200 1 UART, 10 ADC, XLP, 1.38 USD (1.05 USD @1k) PIC24EP32GP202 2 UART, 6 ADC, 2.76 USD (1.86 USD @1k) I knew they had to be there. Again suggesting that the PIC24's probably are a better starting point these days. One (dis)advantage of the Microchip PICs is that there are so many different families and parts. Indeed Bob best, Herbert Bob On May 25, 2013, at 9:05 PM, Bob Camp li...@rtty.us wrote: Hi I just realized the buy direct button on that page requires a login. The single piece direct price is $9.70. First price break is at 25 pieces (to $8.95). Bob On May 25, 2013, at 8:56 PM, Bob Camp li...@rtty.us wrote: Hi It's one of the Freescale K60's they have them in several speeds and packages. Others have similar parts. http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=K60_120nodeId=01624698C9DE2DDDAFtab=Buy_Parametric_TabfromSearch=false hopefully shows the family information The first part on the list is the MK60FN1M0VLQ12 for 8% more money you can get the 150 MHz core rather than the 120 MHz core version. Both have enough pins that you can get at a lot of the peripherals at once. Both have enough pins that they are not a lot of fun to solder by hand. Of course their BGA cousins are even less hand solder friendly…. Bob On May 25, 2013, at 6:48 PM, Graham / KE9H time...@austin.rr.com wrote: On 5/25/2013 3:40 PM, Bob Camp wrote: You can get a part with 1MB of flash, 128KB of ram, 6 UARTS, 4 16 bit A/D's, 10/100 Ethernet, USB, and a bunch of other stuff for less than $10. Drop this and that, go to half the flash, and yup, the price is 1/2. Comes with a free toolchain and two very capable free versions of RTOS. Bob: I was wondering which manufacturer/part you were referring to. Thanks, --- Graham == ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
Hi At least with the newer versions ( the X stuff), they really seem to want to see the PIC Kit 3. Bob On May 25, 2013, at 10:20 PM, Herbert Poetzl herb...@13thfloor.at wrote: On Sat, May 25, 2013 at 10:04:59PM -0400, Bob Camp wrote: Hi If you are putting money into a Microchip programmer, I'd probably head over to the PIC Kit 3 rather than the 2. It will do debug as well as programming on the range of parts. Unfortunately the command line support is missing in the PICkit 3, although there was/is an efford to make the 'new' PICkit 3 compatible with the PICkit 2. (as usualy, marketing decisions ... :) And the PICkit 2 can do all the debugging the PICkit 3 does plus it can work as UART and Logic Analyzer as well. Having breakpoints and debug is a *good* thing. Depends, using breakpoints and/or debug on time critical stuff (like software PWM or UART) usually results in unexpected results, more often it is simpler to add one or more LEDs to display a state or do 'printf' style debugging via serial (UART/I2C/SPI). But as always, YMMV. best, Herbert Bob On May 25, 2013, at 9:44 PM, Herbert Poetzl herb...@13thfloor.at wrote: On Sat, May 25, 2013 at 08:46:03AM -0500, Jason Rabel wrote: I've decided I finally want to tackle learning how to use a PIC chip for some smaller projects. Can someone recommend me a good (and cheap) PIC, and possible some literature (be it a book or website)? I have a fairly recent willem eprom programmer that I'm hoping I can use. Microchip has good product selection tools like this one: http://www.microchip.com/maps/microcontroller.aspx (note the plus signs on the right side of each section) I don't know what all the features PICs have, but for my first project I would like to have it connected to a serial port on one of my Soekris' where it can grab info (i.e. the current time, or NTP/GPS info) and output that on a little LED display. Depending on the type of LED display you have in mind, you want to have PWM capabilities (multiplexing) and high current source/sink, as well as an (E)U(S)ART for the serial communication. A four digit LED display can be easily controlled by a PIC16F1503 (price about 0.8 USD, 14 pins) and the required documents are available on the Microchip site: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en553475 You can do the UART part in software for low data rates or simply take the PIC16F1508/9 which already includes an EUSART (price about 1.3 USD, 20 pins) One programmer for many PIC chips (8 bit to 32 bit) is the PICkit2 which can be bought for less than 30 USD (via usb, works fine on Linux and MacOS as well) HTH, Herbert ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
Hi One of the original starting points was a free tool chain. Paying major money for a compiler is moving a bit far from that. You would have to do a *lot* of home projects to justify that cost. Bob On May 25, 2013, at 10:17 PM, Clint Turner tur...@ussc.com wrote: Having used PICs since 1990, I've designed them into projects rather than getting a board like a Parallax or Arduino (either of which are far more expensive than the chip and the few components required to make it work) and then shoehorning someone else's board into my project. Since the late 90's, I've used the PICC compiler (by CCS) which - once you know it - can produce reasonably tight code that is can also be fast: I've done a number of audio DSP projects on 16F platforms - mostly in C - and had plenty of horsepower. A bit expensive, but I updated only every 4-7 years and with as many projects that I've done (I have used rails of the things with personal/amateur/work projects as well as some commercial prototypes) the time/power is worth the cost. The PICs that I use the most are the 12F683 - an 8-pin device with 10 bits of A/D and a 10 bit PWM: With a 20 MHz xtal, I've done audio DSP with this. As it turns out, a great many projects require =6 pins (the PIC using an internal R/C clock - 1 of the pins is input-only) and this will do the trick. The other one that I use is the 16F88 - It has the A/D, PWM as well as I2C/SCL and USARTs and internal clocks - an 18 pin device, 16 of which can be used for I/O (1 of those only does I). With more RAM/Program memory, one can do more DSP than with the '683... For more horsepower I'll often use the 18F2620/18F4620's - 28/40 pin devices (respectively) and these have more I/O and peripherals. There's are close cousins of this that also has hardware-based USB (I don't recall the number of an example, however...) I've yet to do anything with the 24F and dsPICs, but maybe, the next time I update the compiler... 73, Clint KA7OEI ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
Hi I started out loading Unix via tape on a PDP-11 back in 1974. C has been around for a while. It's also got a bit of baggage from those roots. I do indeed code quite a bit in C, I just don't use it for everything. Different tools for different jobs. Bob On May 25, 2013, at 10:52 PM, Orin Eman orin.e...@gmail.com wrote: On Sat, May 25, 2013 at 6:39 PM, Didier Juges shali...@gmail.com wrote: While I have often said that I have more time than money, I still consider that my time is too scarce (or valuable) for assembly language. My opinion is that the language for small embedded devices is C. Some may disagree, but after over 40 years of writing software for a whole bunch of platforms (obviously not all in C), I see no reason to switch to something else for small embedded systems. Therefore make sure you select a chip/family/architecture for which you can get a decent C compiler. Friends don't let friends write in assembly. I agree entirely. C is pretty close to assembly itself in a way... given its history where *p1++ = *p2++; was one PDP-11 instruction. It's so much easier to get a program going in C than PIC assembly; now which way around do I have to put the operands to subtract a constant? (I had macros to do such things before I switched to a C compiler.) I have tried a few PIC C compilers and actually paid money for the SourceBoost compiler. I look at the assembly output and it usually does at least as good a job as I would. If not and it's timing critical, I can embed some assembly, though the little review I just did showed that the timing critical parts were in C! Orin. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
Hi Jason, Firstly I'm pro PIC so what I say is likely biased ;-) Look at one of the Microchip PicKit 3 (or even PicKit 2) starter kits. See http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGEnodeId=1406dDocName=en538340 The DV164131PicKit 3 Debug Express is about $70 and includes a development board, in-circuit programmer/debugger and C complier. The programmer will also program the earlier series Flash PICs. Pics are great for little projects were an Arduino is to costly or big. The little 8 and 16pin PICs are cheap enough to replace things like 555 timers, discrete logic etc. Throw in an onboard comparator, ADC and PWM you have a whole host of applications it can cope with. If you are not a C person look at ME Labs PicBasicPro, www.melabs.com Don't go for the high end devices and DSPic unless you really need their capabilities. Robert G8RPI. From: Jason Rabel ja...@extremeoverclocking.com To: time-nuts@febo.com Sent: Saturday, 25 May 2013, 20:08 Subject: Re: [time-nuts] Good (cheap) PIC chip choice for project? My reasoning for using a PIC (or similar) is mostly two factors. First, simplicity... The few things I have in my head that I've wanted to do aren't complicated or require special busses. It is things that you could *probably* do with a whole pile of logic chips, or keep it simple with just one PIC. ;) Second, cost... Spending $30-$40 for a one time project is fine. But say after 10 or so, the cost savings of a $2 chip vs $30 embedded system starts to add up. I agree with you that I need to figure out the project details first and what I'm trying to integrate with and work backwards. I'm really glad people are giving me feedback though I didn't know so many different options existed (and at so many different price points). If you don't ask, you will never learn. ;) Both the Arduino and TI Launchpad offerings look very intriguing. I'm on no deadline, so time is not an issue. I just wanted a new challenge and this is something I've wanted to dive into for a long time. Learning a programming language is not an issue. While I mostly write code in PHP, Perl, and shell scripts these days, I used to and am still somewhat familiar with C/C++. Most other programming languages I've used in the past are now probably considered archaic or defunct. ;) Looks like I have a lot of reading to do now. Everyone's responses have been most helpful! Jason How did you decide to use a PIC and not one of the others such as the AVR MSP or whatever? I don't want to argue for any of the others but if you can't list 5 or 6 good reasons to use a PIC and you are not able to say why the oters cn't work for you then you've just selected something at random without thinking. SO as a check, see if you can list pros and cons. You have to decide what you are going to USE the device for first. Some are bets for different purposes. And also how much time you are willing to invest in learning. How much programming experience do you have? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 9390 GPS RX
Those readings look more like an OCXO than an Rb standard. Does it's behaviour as it locks match what I described earlier? You might also have your 5370 counter misconfigured. The 4.43 second Sample Interval suggests that you've got the Display Rate knob turned fully counterclockwise. make sure it's fully clockwise. I can probably give more detailed suggestions if you give me more detailed information on what you're doing and how the unit is responding. Ed On 5/25/2013 8:26 PM, Mark C. Stephens wrote: Hmm, Well looks like everything's checked out except, when I chucked it on time-lab the Allan deviation has gone out the window! Its measuring 6.17E-10 over 1 hour reading. Before I 'fixed' it was 4.99E-12 and I thought that was pretty average. I've attached the .tim's for your perusal. I have to hurry, I have a ton of stuff to get through and also find time to spend with the family too! -marks -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Ed Palmer Sent: Sunday, 26 May 2013 7:54 AM To: time-nuts@febo.com Subject: Re: [time-nuts] 9390 GPS RX On 5/25/2013 12:43 AM, Mark C. Stephens wrote: Hey Ed, Just knocked up a temperature sensor with a Dallas single wire temperature sensor thingy, a pic and an LCD display. So, I will know for sure I am hitting the xtal turning point. I figured you had been right about everything so perhaps my temperature gun was out. It's probably a handy bit of kit to have, because no doubt I have a couple of ovens here that are playing up ad some sort of accurate temperature measurement and logging would be a handy bit of kit to have. It spits out the time and temperature reading once per second via a serial interface as well as displays in on the LCD.. I had already sort of written the code 10 years ago, just hadn't gotten around to finishing the hardware. :) A few changes here and there for the pic pin out and it worked! Just going through the warm-up cycle now, I expect an hour should do it. Seems to be heating that crystal very slowly. I think there still may be a problem around that wee transistor that limits the current to the heater transistor. Or perhaps by putting the right value 6K81 resistor and a new op-amp changed the dynamics and I may need to revisit R8. I have checked the PSU, its 17.3v spot on. I checked the temperature after an hour and it was only 58 degrees ): I stuck a resistance box across R8 and adjusted until I got ~79 on my temperature meter. The resistance is 680R which seems very low to me, but not outside the circuit specifications. As you change R8, watch the frequency of the oscillator as it changes. When your temperature meter shows 79C, is the frequency at its lowest point? Although the frequency changes with age, I've never seen anything to suggest that the turning point changes with age. Anyone reading this, please correct me if I'm wrong. Regardless of the actual temperature, you want to adjust the crystal temperature so that you hit the turning point. For an AT crystal, that will give you the lowest frequency. Once you get to the turning point you will see if you will be able to get it working by changing the capacitors. For test purposes, if the crystal frequency is only slightly out of range, change the temperature with R8 until you can get to 10 MHz. But appear to have dug myself into a hole. It looks like the hole was already there. But you kind of jumped in with both feet! :) I disconnected the EFC as per the manual and hooked up a 10K 'Pot' across the 17.3v supply and the wiper to the crystal boards E9 point (EFC) At zero volts the 10 MHz is very high at around 1500 and at 17.3 volts it is around 1650. So, there is either a problem, with the crystal or the surrounding circuit. If the crystal really has drifted that far you might have trouble pulling it back. Check the temperature as shown above. Note that your frequency is too high and that's just what you would expect if you were away from the crystal turning point. Looking at the circuit C11 and C12 are selectable components. C11 selects the centre frequency and C12 selects the adjust range. The range in the circuit is specified as 4.7 to 100 pf, but my schematic is a bit blurry so it could be 4.7pf to 180pf. So I went from 10pf - 100pf for C11. At 100 Pf the 10Mhz is closest at ~1300 (with 0v EFC) There is no way I will hit 10Mhz by adjusting C11. My copy of the schematic isn't any clearer than yours. But, who cares what the manual says? Load on more capacitance and see what happens. If it works, it works. Make sure that any capacitor you use there is NPO/C0G. I guess my next step is to pull the board out again and check components, especially C3/C4/C5. The manual only talks about C10, C11, and C12 as affecting the frequency. C3 looks like it might resonate with T1 to couple the 10 MHz to the next stage. A fault there would affect the
Re: [time-nuts] Follow-up question re: microcontroller families
Hi Charles, I'm biased, but here goes. With regard to long term support it's hard to beat Microchip products. They still supply (or at least a pin equivalent) and support all their controller products. They built their business on support and low cost, reliable development tools. You are not forced to re-learn everything when you move to a new family either. Robert G8RPI. From: Charles P. Steinmetz charles_steinm...@lavabit.com To: TimeNuts time-nuts@febo.com Sent: Saturday, 25 May 2013, 21:09 Subject: [time-nuts] Follow-up question re: microcontroller families On another thread, Bob wrote: If the objective is to complete a very simple, low powered project and be done with it, go with the Arduino. If the objective is to learn an empire, be very careful about which empire you pick. The ARM boys are quickly gobbling up a lot of territory that once was populated by a number of competing CPU's. Learning this stuff, and getting good at it is a significant investment of time. I'm starting a new thread because I don't want to hijack the first one, which I'm hoping will continue to provide useful information about the broad continuum of available devices, from the easy enough for a child to assemble and program to the need to learn machine language. My question here is more pointed: If one is going to learn a new system today for timing and other measurement/control projects, which empire is likely the best one to choose? Of course, much depends on what do you want to do with it? So, perhaps, the ultimate answer will be several families, each for a class of applications. But on the other hand, some families may have a range of models that fulfill a wide range of applications. Also, my personal approach does not require squeezing each project into the most minimal hardware possible -- as long as the added expense isn't huge, I'm fine with using more resources than necessary for smaller tasks if it means my investment in learning the system (and in programming tools) is leveraged more broadly. Also, my personal needs generally do not run to battery or other low-power systems, so low power drain is not of great importance to me. Some of the more systemic (less application-oriented) factors would be, which system is more versatile? Which has the most useful PC cards (or development kits) available that do not require the user to start with a bare chip? Which is likely to be around and supported longer? Which is easier to program? For which is one likely to find more programs to study and pirate, more libraries, etc.? Which is easier to outfit with removable memory (USB drives, memory cards, etc.)? Which has better and faster ADCs and DACs? I'm sure there are lots of other factors worth considering, as well. There may be good resources already available that address these issues. If so, pointers would be appreciated. Any books people recommend to get a feel for applying and programming these devices? Much appreciated, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
On Sun, May 26, 2013 at 07:48:08AM -0400, Bob Camp wrote: Hi At least with the newer versions ( the X stuff), they really seem to want to see the PIC Kit 3. As I said, it's a marketing move: the PICkit 2 was declared obsolete after the main developer left Microchip and the PICkit 3 was marketed as an 'improved' version, and all new software was geared toward the 'new' PICkit 3, despite the fact that it is inferior to the PICkit 2 in almost all regards Recent updates to the PICkit 3 made it more and more compatible with the PICkit 2 but it is still missing certain features like the uart or logic analyzer. Just google for a comparison (PICkit 2 vs PICkit 3) to get an idea :) Best, Herbert Bob On May 25, 2013, at 10:20 PM, Herbert Poetzl herb...@13thfloor.at wrote: On Sat, May 25, 2013 at 10:04:59PM -0400, Bob Camp wrote: Hi If you are putting money into a Microchip programmer, I'd probably head over to the PIC Kit 3 rather than the 2. It will do debug as well as programming on the range of parts. Unfortunately the command line support is missing in the PICkit 3, although there was/is an efford to make the 'new' PICkit 3 compatible with the PICkit 2. (as usualy, marketing decisions ... :) And the PICkit 2 can do all the debugging the PICkit 3 does plus it can work as UART and Logic Analyzer as well. Having breakpoints and debug is a *good* thing. Depends, using breakpoints and/or debug on time critical stuff (like software PWM or UART) usually results in unexpected results, more often it is simpler to add one or more LEDs to display a state or do 'printf' style debugging via serial (UART/I2C/SPI). But as always, YMMV. best, Herbert Bob On May 25, 2013, at 9:44 PM, Herbert Poetzl herb...@13thfloor.at wrote: On Sat, May 25, 2013 at 08:46:03AM -0500, Jason Rabel wrote: I've decided I finally want to tackle learning how to use a PIC chip for some smaller projects. Can someone recommend me a good (and cheap) PIC, and possible some literature (be it a book or website)? I have a fairly recent willem eprom programmer that I'm hoping I can use. Microchip has good product selection tools like this one: http://www.microchip.com/maps/microcontroller.aspx (note the plus signs on the right side of each section) I don't know what all the features PICs have, but for my first project I would like to have it connected to a serial port on one of my Soekris' where it can grab info (i.e. the current time, or NTP/GPS info) and output that on a little LED display. Depending on the type of LED display you have in mind, you want to have PWM capabilities (multiplexing) and high current source/sink, as well as an (E)U(S)ART for the serial communication. A four digit LED display can be easily controlled by a PIC16F1503 (price about 0.8 USD, 14 pins) and the required documents are available on the Microchip site: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en553475 You can do the UART part in software for low data rates or simply take the PIC16F1508/9 which already includes an EUSART (price about 1.3 USD, 20 pins) One programmer for many PIC chips (8 bit to 32 bit) is the PICkit2 which can be bought for less than 30 USD (via usb, works fine on Linux and MacOS as well) HTH, Herbert ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Follow-up question re: microcontroller families
On Sun, May 26, 2013 at 07:46:38AM -0400, Bob Camp wrote: Hi On May 25, 2013, at 11:26 PM, Herbert Poetzl herb...@13thfloor.at wrote: On Sat, May 25, 2013 at 09:26:02PM -0400, Bob Camp wrote: Hi I realize this is a bit like water torture - sorry about that. If I go to Microchip Direct and ask for a PIC 18F with two UARTS and two A/D's I get the PIC18F86J72 and PIC 18F87J72. To me the second one is the obvious winner. It's got twice the flash for next to nothing more money. 1-25 piece price is $6.04. Same search, 1 A/D, 4 UARTS, lowest cost this time. PIC18F65J94 is the winner. Lowest price package is $3.30 in 1-25 pieces. 4 UARTS are untypical for PICs and result in higher price as the device usually has more pins (which makes them more expensive) The ARM that the thread was looking at was a 6 UART / 4 A/D part. Thus the load up the UARTS. Also the starting point for all this did involve serial i/o. I have no idea for what 'home' project you would make good use of 6 UARTs, but please don't get me wrong, I'm using a lot of ARM/MIPS microcontrollers and devices here, and I appreciate that they got really cheap over the years. But for many applications, the inevitable overhead (power, heat, external components, OS, etc) simply eliminates the gain of having a better/faster CPU. Sometimes I end up using a 6 or 8 pin PIC with only a few lines of code to to solve complex problems where a (F)PGA/CPLD design would be a lot of work and a 16/32bit microcontroller simply overkill. As always, YMMV, best, Herbert Are those some *very* arbitrary choices - you bet they are. They are random picks, and were not optimized to show any particular thing. Only to target an application that had some serial i/o and a bit of A/D involvement. Bottom line - not all PIC's are $1. once you start adding peripherals. For $6 over in ARM land, you can get a lot of chip. To be fair, my experience has been that you can do better in the PIC24 line once you start adding stuff. Searching the PIC24's is hard enough that my brief search tonight did not show up a lower cost part. PIC24F04KA200 1 UART, 10 ADC, XLP, 1.38 USD (1.05 USD @1k) PIC24EP32GP202 2 UART, 6 ADC, 2.76 USD (1.86 USD @1k) I knew they had to be there. Again suggesting that the PIC24's probably are a better starting point these days. One (dis)advantage of the Microchip PICs is that there are so many different families and parts. Indeed Bob best, Herbert Bob On May 25, 2013, at 9:05 PM, Bob Camp li...@rtty.us wrote: Hi I just realized the buy direct button on that page requires a login. The single piece direct price is $9.70. First price break is at 25 pieces (to $8.95). Bob On May 25, 2013, at 8:56 PM, Bob Camp li...@rtty.us wrote: Hi It's one of the Freescale K60's they have them in several speeds and packages. Others have similar parts. http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=K60_120nodeId=01624698C9DE2DDDAFtab=Buy_Parametric_TabfromSearch=false hopefully shows the family information The first part on the list is the MK60FN1M0VLQ12 for 8% more money you can get the 150 MHz core rather than the 120 MHz core version. Both have enough pins that you can get at a lot of the peripherals at once. Both have enough pins that they are not a lot of fun to solder by hand. Of course their BGA cousins are even less hand solder friendly…. Bob On May 25, 2013, at 6:48 PM, Graham / KE9H time...@austin.rr.com wrote: On 5/25/2013 3:40 PM, Bob Camp wrote: You can get a part with 1MB of flash, 128KB of ram, 6 UARTS, 4 16 bit A/D's, 10/100 Ethernet, USB, and a bunch of other stuff for less than $10. Drop this and that, go to half the flash, and yup, the price is 1/2. Comes with a free toolchain and two very capable free versions of RTOS. Bob: I was wondering which manufacturer/part you were referring to. Thanks, --- Graham == ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the
Re: [time-nuts] Follow-up question re: microcontroller families
But for many applications, the inevitable overhead (power, heat, external components, OS, etc) simply eliminates the gain of having a better/faster CPU. Sometimes I end up using a 6 or 8 pin PIC with only a few lines of code to to solve complex problems where a (F)PGA/CPLD design would be a lot of work and a 16/32bit microcontroller simply overkill. As it turns out there are a LOT more simple jobs than there are complex jobs. This is why they make and sel a lot motr 8-t controllers than they sell 32-bit controllers. For example I want to control the cooling fan for a rubidium oscillator's heat sink. I only need three pins, 1) the temperature sensor, 2) Fan tachometer pulse, fan voltage. A $1 tiny AVR 8-pin chip can handle this just fine and we are talking about 20 lines of code maybe after the pins are set up. Using an ARM and running an OS would be silly overkill. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Looking for datasheet for Oscilloquartz 8602
Hi, I'm looking for the datasheet of the Oscilloquartz 8602 oscillator. I cannot find it at the usual places or anywhere with google. Any help would be appreciated Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Looking for datasheet for Oscilloquartz 8602
On 05/26/2013 06:04 PM, Attila Kinali wrote: Hi, I'm looking for the datasheet of the Oscilloquartz 8602 oscillator. I cannot find it at the usual places or anywhere with google. Any help would be appreciated The OSA 8602 is a variant of the OSA 8600 and 8601. These variants is mainly on the connection on the front. I don't have a 8602 datasheet as such, but I have some 8602 related specs as found in the extended OSA 3000 manual. It is essentially the same AT-cut oscillator that you can expect from the 8600 base. What information are you really seeking? Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Follow-up question re: microcontroller families
On 5/26/13 9:00 AM, Chris Albertson wrote: But for many applications, the inevitable overhead (power, heat, external components, OS, etc) simply eliminates the gain of having a better/faster CPU. Sometimes I end up using a 6 or 8 pin PIC with only a few lines of code to to solve complex problems where a (F)PGA/CPLD design would be a lot of work and a 16/32bit microcontroller simply overkill. As it turns out there are a LOT more simple jobs than there are complex jobs. This is why they make and sel a lot motr 8-t controllers than they sell 32-bit controllers. For example I want to control the cooling fan for a rubidium oscillator's heat sink. I only need three pins, 1) the temperature sensor, 2) Fan tachometer pulse, fan voltage. A $1 tiny AVR 8-pin chip can handle this just fine and we are talking about 20 lines of code maybe after the pins are set up. Using an ARM and running an OS would be silly overkill. The other thing is packaging and peripherals..not to mention development time. It might be more cost effective (where cost is some complex conglomeration of your time and money) to always use the same part, even if overkill. Some people are happy to layout a new PCB, get it fabbed (or make it themselves) or deadbug it. Others might want a board with terminal strips. Or you might want something that you have a box for or maybe you like mounting it inside. I think everyone has their favorites, and most folks tend to have relatively few candidates at any given time (it's difficult to switch among various processors on a day to day basis). Right now, I tend to use Matlab on PCs for big things, with some python. For smaller needs, I've been using lots of Arduino Uno R3s and Teensy3s, because of the packaging. Both using the Arduino semi-C tool chain and also the non-arduino compilers. (having a USB boot loader, etc, does make life easier). I've used PICs and Rabbits in the not too recent past, but the Rabbits don't have as nice a development environment, and there's no equivalent of the $20 Arduino, nor the plethora of cheap interfaces to things like relays and what not. I haven't looked much at whether a low cost PIC on a board with peripherals is available. They've always been a build a circuit either with perfboard, deadbug, or small PCB, and that makes it take a few more hours or days. For the I want to finish the project this weekend starting Saturday afternoon, the whole arduino world is pretty convenient, at least as far as getting the hardware put together and a first load of software running. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] NTP on RaspberryPi
Besides I got them to run NTP and they're too jittery for my taste. How good/bad were they? What were you using for a time source? Does it have PPS support? Here's ntpq -c pv for one of my RPIs after 25 days of uptime: associd=0 status=0615 leap_none, sync_ntp, 1 event, clock_sync, version=ntpd 4.2.6p5@1.2349-o Fri May 18 20:30:57 UTC 2012 (1), processor=armv6l, system=Linux/3.8.10+, leap=00, stratum=3, precision=-20, rootdelay=25.184, rootdisp=73.646, refid=83.98.201.134, reftime=d54cac1f.18aa9126 Sun, May 26 2013 17:43:27.096, clock=d54cb273.b755933f Sun, May 26 2013 18:10:27.716, peer=34195, tc=10, mintc=3, offset=0.182, frequency=-47.006, sys_jitter=0.377, clk_jitter=0.558, clk_wander=0.051 Hmmm found out that it syncs to random hosts on the internet. Ok an other one which syncs against an other pc with PPS (and a few others): folkert@weerpi ~ $ ntpq -c rv associd=0 status=0615 leap_none, sync_ntp, 1 event, clock_sync, version=ntpd 4.2.6p5@1.2349-o Fri May 18 20:30:57 UTC 2012 (1), processor=armv6l, system=Linux/3.8.10+, leap=00, stratum=2, precision=-20, rootdelay=0.807, rootdisp=7.669, refid=192.168.64.100, reftime=d54cb1e1.9d6e8f07 Sun, May 26 2013 18:08:01.614, clock=d54cb2e4.7d1cdae3 Sun, May 26 2013 18:12:20.488, peer=41936, tc=9, mintc=3, offset=0.220, frequency=-31.405, sys_jitter=0.647, clk_jitter=0.074, clk_wander=0.003 folkert@weerpi ~ $ uptime 18:12:25 up 15 days, 3:48, 1 user, load average: 0.12, 0.17, 0.15 Folkert van Heusden -- Multitail est un outil permettant la visualisation de fichiers de journalisation et/ou le suivi de l'exécution de commandes. Filtrage, mise en couleur de mot-clé, fusions, visualisation de différences (diff-view), etc. http://www.vanheusden.com/multitail/ -- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] NTP on RaspberryPi
NTP does not really sync to a server. What it does is use the set of reference clocks that pas the clock selection criteria. THere is an algorithm that determines if a reference clock is reasonable or not.A reference clock can be a GPS or another NTP server or a cell phone service or any of a dozen other things but GPS and other servers are by far the most common. Your RPI is three leves removed from a GPS. It is operating as stratum 3 the second RPI is stratum 2. Both are doing really good for using a networked ref. clock. I would not blain the RPI. If you are doing better than a millisecond with no local PPS it is good. On Sun, May 26, 2013 at 9:15 AM, folkert folk...@vanheusden.com wrote: Besides I got them to run NTP and they're too jittery for my taste. How good/bad were they? What were you using for a time source? Does it have PPS support? Here's ntpq -c pv for one of my RPIs after 25 days of uptime: associd=0 status=0615 leap_none, sync_ntp, 1 event, clock_sync, version=ntpd 4.2.6p5@1.2349-o Fri May 18 20:30:57 UTC 2012 (1), processor=armv6l, system=Linux/3.8.10+, leap=00, stratum=3, precision=-20, rootdelay=25.184, rootdisp=73.646, refid=83.98.201.134, reftime=d54cac1f.18aa9126 Sun, May 26 2013 17:43:27.096, clock=d54cb273.b755933f Sun, May 26 2013 18:10:27.716, peer=34195, tc=10, mintc=3, offset=0.182, frequency=-47.006, sys_jitter=0.377, clk_jitter=0.558, clk_wander=0.051 Hmmm found out that it syncs to random hosts on the internet. Ok an other one which syncs against an other pc with PPS (and a few others): folkert@weerpi ~ $ ntpq -c rv associd=0 status=0615 leap_none, sync_ntp, 1 event, clock_sync, version=ntpd 4.2.6p5@1.2349-o Fri May 18 20:30:57 UTC 2012 (1), processor=armv6l, system=Linux/3.8.10+, leap=00, stratum=2, precision=-20, rootdelay=0.807, rootdisp=7.669, refid=192.168.64.100, reftime=d54cb1e1.9d6e8f07 Sun, May 26 2013 18:08:01.614, clock=d54cb2e4.7d1cdae3 Sun, May 26 2013 18:12:20.488, peer=41936, tc=9, mintc=3, offset=0.220, frequency=-31.405, sys_jitter=0.647, clk_jitter=0.074, clk_wander=0.003 folkert@weerpi ~ $ uptime 18:12:25 up 15 days, 3:48, 1 user, load average: 0.12, 0.17, 0.15 Folkert van Heusden -- Multitail est un outil permettant la visualisation de fichiers de journalisation et/ou le suivi de l'exécution de commandes. Filtrage, mise en couleur de mot-clé, fusions, visualisation de différences (diff-view), etc. http://www.vanheusden.com/multitail/ -- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Follow-up question re: microcontroller families
Hi On May 26, 2013, at 11:21 AM, Herbert Poetzl herb...@13thfloor.at wrote: On Sun, May 26, 2013 at 07:46:38AM -0400, Bob Camp wrote: Hi On May 25, 2013, at 11:26 PM, Herbert Poetzl herb...@13thfloor.at wrote: On Sat, May 25, 2013 at 09:26:02PM -0400, Bob Camp wrote: Hi I realize this is a bit like water torture - sorry about that. If I go to Microchip Direct and ask for a PIC 18F with two UARTS and two A/D's I get the PIC18F86J72 and PIC 18F87J72. To me the second one is the obvious winner. It's got twice the flash for next to nothing more money. 1-25 piece price is $6.04. Same search, 1 A/D, 4 UARTS, lowest cost this time. PIC18F65J94 is the winner. Lowest price package is $3.30 in 1-25 pieces. 4 UARTS are untypical for PICs and result in higher price as the device usually has more pins (which makes them more expensive) The ARM that the thread was looking at was a 6 UART / 4 A/D part. Thus the load up the UARTS. Also the starting point for all this did involve serial i/o. I have no idea for what 'home' project you would make good use of 6 UARTs, One port to grab pps sawtooth data from the LEA-6T GPS One port to steer the FE-5680 rubidium One port to the console / logger / debug One port to drive pps into NTP on the PC One port to grab data out of the 53131 monitor counter One spare but please don't get me wrong, I'm using a lot of ARM/MIPS microcontrollers and devices here, and I appreciate that they got really cheap over the years. But for many applications, the inevitable overhead (power, heat, external components, OS, etc) simply eliminates the gain of having a better/faster CPU. The ARM part I mentioned earlier runs much the same way as a PIC. You can run on it's internal oscillator, add a crystal (or two), or dump a clock oscillator into it. Past that it's stand alone unless you implement USB or Ethernet. In both cases you add a connector and a few bits here and there. Current wise it pulls about 90 mils at 1.8 to 3.6 volts running at 150 MHz. You can throttle it back so it runs on a few microamps if you wish. Like the PIC it's perfectly happy with an unregulated supply, within limits. The full trace and debug connector is 20 pins, a simple programing connector with limited debug is 10 pins. All this is in no way unique to that part, All of the M0's and M4's I've seen are similar. The RTOS is free and the lightweight version has a very cute configuration wizard. It's literally a zero to up and running in less than a day sort of thing. Since it adds things like interrupt driven buffered serial I/O it's quite a bit faster than writing the code from scratch. If you head off into USB plus Ethernet, an OS is pretty much a necessary evil. The specific RTOS is Freescale specific. Other vendors toss in their favorite OS (or not…). My guess is that those in the not category soon will start supplying one, simply to keep up. My belief is that for a one off home project, the OS with all the wizard configured drivers is very much the way to go. Your time would have to be worth very little to make it worth writing all that code from scratch for a one up. The free tool chain is Eclipse / GCC. You can love it or hate it (or both at once). The ARM toolchain is nontrivially expensive with debug. It's certainly better, but to my mind out of range for a home only setup. What is *very* true is that soldering a bazillion pins when you only need a dozen is a bit crazy. The M0 parts get down to sub 32 pin packages at sub $1 sort of prices. You loose the Ethernet, and probably USB. You do keep some UARTS and A/D's even on the smaller parts. 32 pins is not a lot, so getting at everything at once will be a chore. Lots of choices at many price points. Bob Sometimes I end up using a 6 or 8 pin PIC with only a few lines of code to to solve complex problems where a (F)PGA/CPLD design would be a lot of work and a 16/32bit microcontroller simply overkill. As always, YMMV, best, Herbert Are those some *very* arbitrary choices - you bet they are. They are random picks, and were not optimized to show any particular thing. Only to target an application that had some serial i/o and a bit of A/D involvement. Bottom line - not all PIC's are $1. once you start adding peripherals. For $6 over in ARM land, you can get a lot of chip. To be fair, my experience has been that you can do better in the PIC24 line once you start adding stuff. Searching the PIC24's is hard enough that my brief search tonight did not show up a lower cost part. PIC24F04KA200 1 UART, 10 ADC, XLP, 1.38 USD (1.05 USD @1k) PIC24EP32GP202 2 UART, 6 ADC, 2.76 USD (1.86 USD @1k) I knew they had to be there. Again suggesting that the PIC24's probably are a better starting point these days. One (dis)advantage of the Microchip PICs is that there are so many different families and parts. Indeed Bob best, Herbert Bob On May 25, 2013,
Re: [time-nuts] Follow-up question re: microcontroller families
A fan controller (8-pin DIP package) is simple enough to build on perf board. But mostly I agree that it is best to buy these on PCBs. You can use them right out of the box. I do have an Arduino and it's advantage is that you can build very fast. I had a device that measured the resistance across a pot and displayed the value on a 2x16 LCD working about 40 minutes after I got the Arduino un-boxed. It is easy and fast. But they cost a few $$ A cheaper alternative I think I like is TI's launchpads They come on little credit card sized PCBs and the concept of very much the same as Arduino. TI sells several. One is a $13 ARM Cortex M4. It is a complete development system. The other is a MSP430 version for $10. But with the MSP versionyou can remove the uP after it is programmer if you like, or leave it on the board. These prices include shipping. $13 is good pice for an ARM on a breakout board. They also sell an assortment of booster boards that plug in and provide all kinds of interfaces, pretty much the same concept as Arduino shields More info here: /launchpad/overview_head.htmlhttp://www.ti.com/ww/en/launchpad/overview_head.html On Sun, May 26, 2013 at 9:18 AM, Jim Lux jim...@earthlink.net wrote: On 5/26/13 9:00 AM, Chris Albertson wrote: But for many applications, the inevitable overhead (power, heat, external components, OS, etc) simply eliminates the gain of having a better/faster CPU. Sometimes I end up using a 6 or 8 pin PIC with only a few lines of code to to solve complex problems where a (F)PGA/CPLD design would be a lot of work and a 16/32bit microcontroller simply overkill. As it turns out there are a LOT more simple jobs than there are complex jobs. This is why they make and sel a lot motr 8-t controllers than they sell 32-bit controllers. For example I want to control the cooling fan for a rubidium oscillator's heat sink. I only need three pins, 1) the temperature sensor, 2) Fan tachometer pulse, fan voltage. A $1 tiny AVR 8-pin chip can handle this just fine and we are talking about 20 lines of code maybe after the pins are set up. Using an ARM and running an OS would be silly overkill. The other thing is packaging and peripherals..not to mention development time. It might be more cost effective (where cost is some complex conglomeration of your time and money) to always use the same part, even if overkill. Some people are happy to layout a new PCB, get it fabbed (or make it themselves) or deadbug it. Others might want a board with terminal strips. Or you might want something that you have a box for or maybe you like mounting it inside. I think everyone has their favorites, and most folks tend to have relatively few candidates at any given time (it's difficult to switch among various processors on a day to day basis). Right now, I tend to use Matlab on PCs for big things, with some python. For smaller needs, I've been using lots of Arduino Uno R3s and Teensy3s, because of the packaging. Both using the Arduino semi-C tool chain and also the non-arduino compilers. (having a USB boot loader, etc, does make life easier). I've used PICs and Rabbits in the not too recent past, but the Rabbits don't have as nice a development environment, and there's no equivalent of the $20 Arduino, nor the plethora of cheap interfaces to things like relays and what not. I haven't looked much at whether a low cost PIC on a board with peripherals is available. They've always been a build a circuit either with perfboard, deadbug, or small PCB, and that makes it take a few more hours or days. For the I want to finish the project this weekend starting Saturday afternoon, the whole arduino world is pretty convenient, at least as far as getting the hardware put together and a first load of software running. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Follow-up question re: microcontroller families
Hi If you head over to the auction sites and do a bit of creative digging / bidding, the Arduino clones are amazingly cheap. They easily beat the $12 or so Freescale and TI demo boards by a wide margin cost wise. Bang for the buck wise, indeed the demo boards win out. For blinking a LED, running out of horsepower isn't a major concern with any of them. Bob On May 26, 2013, at 1:19 PM, Chris Albertson albertson.ch...@gmail.com wrote: A fan controller (8-pin DIP package) is simple enough to build on perf board. But mostly I agree that it is best to buy these on PCBs. You can use them right out of the box. I do have an Arduino and it's advantage is that you can build very fast. I had a device that measured the resistance across a pot and displayed the value on a 2x16 LCD working about 40 minutes after I got the Arduino un-boxed. It is easy and fast. But they cost a few $$ A cheaper alternative I think I like is TI's launchpads They come on little credit card sized PCBs and the concept of very much the same as Arduino. TI sells several. One is a $13 ARM Cortex M4. It is a complete development system. The other is a MSP430 version for $10. But with the MSP versionyou can remove the uP after it is programmer if you like, or leave it on the board. These prices include shipping. $13 is good pice for an ARM on a breakout board. They also sell an assortment of booster boards that plug in and provide all kinds of interfaces, pretty much the same concept as Arduino shields More info here: /launchpad/overview_head.htmlhttp://www.ti.com/ww/en/launchpad/overview_head.html On Sun, May 26, 2013 at 9:18 AM, Jim Lux jim...@earthlink.net wrote: On 5/26/13 9:00 AM, Chris Albertson wrote: But for many applications, the inevitable overhead (power, heat, external components, OS, etc) simply eliminates the gain of having a better/faster CPU. Sometimes I end up using a 6 or 8 pin PIC with only a few lines of code to to solve complex problems where a (F)PGA/CPLD design would be a lot of work and a 16/32bit microcontroller simply overkill. As it turns out there are a LOT more simple jobs than there are complex jobs. This is why they make and sel a lot motr 8-t controllers than they sell 32-bit controllers. For example I want to control the cooling fan for a rubidium oscillator's heat sink. I only need three pins, 1) the temperature sensor, 2) Fan tachometer pulse, fan voltage. A $1 tiny AVR 8-pin chip can handle this just fine and we are talking about 20 lines of code maybe after the pins are set up. Using an ARM and running an OS would be silly overkill. The other thing is packaging and peripherals..not to mention development time. It might be more cost effective (where cost is some complex conglomeration of your time and money) to always use the same part, even if overkill. Some people are happy to layout a new PCB, get it fabbed (or make it themselves) or deadbug it. Others might want a board with terminal strips. Or you might want something that you have a box for or maybe you like mounting it inside. I think everyone has their favorites, and most folks tend to have relatively few candidates at any given time (it's difficult to switch among various processors on a day to day basis). Right now, I tend to use Matlab on PCs for big things, with some python. For smaller needs, I've been using lots of Arduino Uno R3s and Teensy3s, because of the packaging. Both using the Arduino semi-C tool chain and also the non-arduino compilers. (having a USB boot loader, etc, does make life easier). I've used PICs and Rabbits in the not too recent past, but the Rabbits don't have as nice a development environment, and there's no equivalent of the $20 Arduino, nor the plethora of cheap interfaces to things like relays and what not. I haven't looked much at whether a low cost PIC on a board with peripherals is available. They've always been a build a circuit either with perfboard, deadbug, or small PCB, and that makes it take a few more hours or days. For the I want to finish the project this weekend starting Saturday afternoon, the whole arduino world is pretty convenient, at least as far as getting the hardware put together and a first load of software running. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
Re: [time-nuts] Follow-up question re: microcontroller families
I use the Arduino as a rapid prototype development platform. I build the application and the hardware on the Arduino and then move the cpu to a standalone board. You can also use the Arduino as a programmer much like someone else suggested. Bob On May 26, 2013, at 13:19, Chris Albertson albertson.ch...@gmail.com wrote: A fan controller (8-pin DIP package) is simple enough to build on perf board. But mostly I agree that it is best to buy these on PCBs. You can use them right out of the box. I do have an Arduino and it's advantage is that you can build very fast. I had a device that measured the resistance across a pot and displayed the value on a 2x16 LCD working about 40 minutes after I got the Arduino un-boxed. It is easy and fast. But they cost a few $$ A cheaper alternative I think I like is TI's launchpads They come on little credit card sized PCBs and the concept of very much the same as Arduino. TI sells several. One is a $13 ARM Cortex M4. It is a complete development system. The other is a MSP430 version for $10. But with the MSP versionyou can remove the uP after it is programmer if you like, or leave it on the board. These prices include shipping. $13 is good pice for an ARM on a breakout board. They also sell an assortment of booster boards that plug in and provide all kinds of interfaces, pretty much the same concept as Arduino shields More info here: /launchpad/overview_head.htmlhttp://www.ti.com/ww/en/launchpad/overview_head.html On Sun, May 26, 2013 at 9:18 AM, Jim Lux jim...@earthlink.net wrote: On 5/26/13 9:00 AM, Chris Albertson wrote: But for many applications, the inevitable overhead (power, heat, external components, OS, etc) simply eliminates the gain of having a better/faster CPU. Sometimes I end up using a 6 or 8 pin PIC with only a few lines of code to to solve complex problems where a (F)PGA/CPLD design would be a lot of work and a 16/32bit microcontroller simply overkill. As it turns out there are a LOT more simple jobs than there are complex jobs. This is why they make and sel a lot motr 8-t controllers than they sell 32-bit controllers. For example I want to control the cooling fan for a rubidium oscillator's heat sink. I only need three pins, 1) the temperature sensor, 2) Fan tachometer pulse, fan voltage. A $1 tiny AVR 8-pin chip can handle this just fine and we are talking about 20 lines of code maybe after the pins are set up. Using an ARM and running an OS would be silly overkill. The other thing is packaging and peripherals..not to mention development time. It might be more cost effective (where cost is some complex conglomeration of your time and money) to always use the same part, even if overkill. Some people are happy to layout a new PCB, get it fabbed (or make it themselves) or deadbug it. Others might want a board with terminal strips. Or you might want something that you have a box for or maybe you like mounting it inside. I think everyone has their favorites, and most folks tend to have relatively few candidates at any given time (it's difficult to switch among various processors on a day to day basis). Right now, I tend to use Matlab on PCs for big things, with some python. For smaller needs, I've been using lots of Arduino Uno R3s and Teensy3s, because of the packaging. Both using the Arduino semi-C tool chain and also the non-arduino compilers. (having a USB boot loader, etc, does make life easier). I've used PICs and Rabbits in the not too recent past, but the Rabbits don't have as nice a development environment, and there's no equivalent of the $20 Arduino, nor the plethora of cheap interfaces to things like relays and what not. I haven't looked much at whether a low cost PIC on a board with peripherals is available. They've always been a build a circuit either with perfboard, deadbug, or small PCB, and that makes it take a few more hours or days. For the I want to finish the project this weekend starting Saturday afternoon, the whole arduino world is pretty convenient, at least as far as getting the hardware put together and a first load of software running. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Follow-up question re: microcontroller families
For making a blinking LEDs, it is hard to beat a 74LS74. However, a PIC, is probably less expensive! :) On May 26, 2013, at 13:33, Bob Camp li...@rtty.us wrote: Hi If you head over to the auction sites and do a bit of creative digging / bidding, the Arduino clones are amazingly cheap. They easily beat the $12 or so Freescale and TI demo boards by a wide margin cost wise. Bang for the buck wise, indeed the demo boards win out. For blinking a LED, running out of horsepower isn't a major concern with any of them. Bob On May 26, 2013, at 1:19 PM, Chris Albertson albertson.ch...@gmail.com wrote: A fan controller (8-pin DIP package) is simple enough to build on perf board. But mostly I agree that it is best to buy these on PCBs. You can use them right out of the box. I do have an Arduino and it's advantage is that you can build very fast. I had a device that measured the resistance across a pot and displayed the value on a 2x16 LCD working about 40 minutes after I got the Arduino un-boxed. It is easy and fast. But they cost a few $$ A cheaper alternative I think I like is TI's launchpads They come on little credit card sized PCBs and the concept of very much the same as Arduino. TI sells several. One is a $13 ARM Cortex M4. It is a complete development system. The other is a MSP430 version for $10. But with the MSP versionyou can remove the uP after it is programmer if you like, or leave it on the board. These prices include shipping. $13 is good pice for an ARM on a breakout board. They also sell an assortment of booster boards that plug in and provide all kinds of interfaces, pretty much the same concept as Arduino shields More info here: /launchpad/overview_head.htmlhttp://www.ti.com/ww/en/launchpad/overview_head.html On Sun, May 26, 2013 at 9:18 AM, Jim Lux jim...@earthlink.net wrote: On 5/26/13 9:00 AM, Chris Albertson wrote: But for many applications, the inevitable overhead (power, heat, external components, OS, etc) simply eliminates the gain of having a better/faster CPU. Sometimes I end up using a 6 or 8 pin PIC with only a few lines of code to to solve complex problems where a (F)PGA/CPLD design would be a lot of work and a 16/32bit microcontroller simply overkill. As it turns out there are a LOT more simple jobs than there are complex jobs. This is why they make and sel a lot motr 8-t controllers than they sell 32-bit controllers. For example I want to control the cooling fan for a rubidium oscillator's heat sink. I only need three pins, 1) the temperature sensor, 2) Fan tachometer pulse, fan voltage. A $1 tiny AVR 8-pin chip can handle this just fine and we are talking about 20 lines of code maybe after the pins are set up. Using an ARM and running an OS would be silly overkill. The other thing is packaging and peripherals..not to mention development time. It might be more cost effective (where cost is some complex conglomeration of your time and money) to always use the same part, even if overkill. Some people are happy to layout a new PCB, get it fabbed (or make it themselves) or deadbug it. Others might want a board with terminal strips. Or you might want something that you have a box for or maybe you like mounting it inside. I think everyone has their favorites, and most folks tend to have relatively few candidates at any given time (it's difficult to switch among various processors on a day to day basis). Right now, I tend to use Matlab on PCs for big things, with some python. For smaller needs, I've been using lots of Arduino Uno R3s and Teensy3s, because of the packaging. Both using the Arduino semi-C tool chain and also the non-arduino compilers. (having a USB boot loader, etc, does make life easier). I've used PICs and Rabbits in the not too recent past, but the Rabbits don't have as nice a development environment, and there's no equivalent of the $20 Arduino, nor the plethora of cheap interfaces to things like relays and what not. I haven't looked much at whether a low cost PIC on a board with peripherals is available. They've always been a build a circuit either with perfboard, deadbug, or small PCB, and that makes it take a few more hours or days. For the I want to finish the project this weekend starting Saturday afternoon, the whole arduino world is pretty convenient, at least as far as getting the hardware put together and a first load of software running. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions
[time-nuts] Temex LPFRS-01 / LPRO rubidium reference repair
Hi, I bought a used Temex LPFRS-01 / LPRO from fluke.l on ebay. Unfortunately the unit is broken and shows the same defect as was mentioned about a year ago on this list: after warm-up it locks for a few seconds, but lock is lost again after a few seconds. The lock output pulls low for a few very short intervals afterwards, but that's it. I got a refund (but excl. the VAT I had to pay at customs), so it's just a small loss. But of course I want to try to get this thing alive again. In the post last year it was mentioned that these used units suffered from some kind of water damage inside. So I opened up the unit, but it looks clean inside. Just very small signs of surface rust on the screws and connector. Here are some teardown photos I made: http://www.egidy.de/temex_lpfrs_lpro/ I have connected the serial terminal. When using the M command for monitoring, the unit returns detailed data. The rb signal level is too low on my unit, see the screenshot at the link above. Was anybody here already able to fix such a unit? Any ideas what to look for or other insights? Kind regards, Gerd ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Selecting a Microcontroller
The two threads here, Good (cheap) PIC chip choice for project? and Follow-up question re: microcontroller families have a lot of good information. A more organized approach is available at the Digi-Key/Design News Continuing Education Center which has several free courses on microcontroller basics and selecting a microcontroller. You download a Powerpoint presentation and follow along to an audio stream. For example: Microcontrollers, Basics; Microcontrollers, Advanced; and Hands-On Analysis of Five MCU Development Kits at http://www.designnews.com/lecture-calendar.asp?p_l_ed=CEC_Semester_One_2012 ARM Cortex-M0 at http://www.designnews.com/lecture-calendar.asp?p_l_ed=CEC_Semester_Two_2012 How to Choose a Microcontroller Architecture at http://www.designnews.com/lecture-calendar.asp?p_l_ed=CEC_Semester_Three_2013 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Temex LPFRS-01 / LPRO rubidium reference repair
Hi Check the output frequency of the unit as it sweeps. I'd bet it's not quite making it to 10 MHz. Look for a trimmer cap near the master crystal. It should be possible to tweak it so the sweep makes it to either side of 10 MHz. Bob On May 26, 2013, at 1:43 PM, Gerd v. Egidy li...@egidy.de wrote: Hi, I bought a used Temex LPFRS-01 / LPRO from fluke.l on ebay. Unfortunately the unit is broken and shows the same defect as was mentioned about a year ago on this list: after warm-up it locks for a few seconds, but lock is lost again after a few seconds. The lock output pulls low for a few very short intervals afterwards, but that's it. I got a refund (but excl. the VAT I had to pay at customs), so it's just a small loss. But of course I want to try to get this thing alive again. In the post last year it was mentioned that these used units suffered from some kind of water damage inside. So I opened up the unit, but it looks clean inside. Just very small signs of surface rust on the screws and connector. Here are some teardown photos I made: http://www.egidy.de/temex_lpfrs_lpro/ I have connected the serial terminal. When using the M command for monitoring, the unit returns detailed data. The rb signal level is too low on my unit, see the screenshot at the link above. Was anybody here already able to fix such a unit? Any ideas what to look for or other insights? Kind regards, Gerd ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Temex LPFRS-01 / LPRO rubidium reference repair
I don't have an LPFRS, but if I'm reading the manual correctly, the fourth column of numbers on the 'M' command (4D, 4C on your screen capture) is the VCXO control voltage. Shouldn't this be continuously sweeping up and down until it finds lock? Does the output frequency sweep up and down and is 10 MHz somewhere in the sweep? I think that the second column (Rb Level) will only be valid after the unit locks. The first column (Photocell DC voltage) shows that you've got lots of light from the lamp. Ed On 5/26/2013 11:43 AM, Gerd v. Egidy wrote: Hi, I bought a used Temex LPFRS-01 / LPRO from fluke.l on ebay. Unfortunately the unit is broken and shows the same defect as was mentioned about a year ago on this list: after warm-up it locks for a few seconds, but lock is lost again after a few seconds. The lock output pulls low for a few very short intervals afterwards, but that's it. I got a refund (but excl. the VAT I had to pay at customs), so it's just a small loss. But of course I want to try to get this thing alive again. In the post last year it was mentioned that these used units suffered from some kind of water damage inside. So I opened up the unit, but it looks clean inside. Just very small signs of surface rust on the screws and connector. Here are some teardown photos I made: http://www.egidy.de/temex_lpfrs_lpro/ I have connected the serial terminal. When using the M command for monitoring, the unit returns detailed data. The rb signal level is too low on my unit, see the screenshot at the link above. Was anybody here already able to fix such a unit? Any ideas what to look for or other insights? Kind regards, Gerd ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
On Sun, May 26, 2013 at 4:50 AM, Bob Camp li...@rtty.us wrote: Hi One of the original starting points was a free tool chain. Paying major money for a compiler is moving a bit far from that. You would have to do a *lot* of home projects to justify that cost. Indeed. I wouldn't pay commercial prices for a PIC C compiler for home projects. The 'Lite' version of SourceBoost that I actually bought is a whopping $5 and in spite of its RAM/ROM limitations, it's been good enough for me. If I ever sell a product that uses it, I'd need the commercial version at $150 - fair enough IMO. Orin. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Temex LPFRS-01 / LPRO rubidium reference repair
Hi Ed, I don't have an LPFRS, but if I'm reading the manual correctly, the fourth column of numbers on the 'M' command (4D, 4C on your screen capture) is the VCXO control voltage. Shouldn't this be continuously sweeping up and down until it finds lock? You are right, it sweeps the control voltage up and down and the output frequency changes. But that is only happening during warmup. Once the unit had this short lock for a few seconds, it stops sweeping and does not start again even after losing the lock. Maybe a firmware issue not taking aging into account or something. The terminal output in my screenshot is from the time after the short lock, so you don't see any sweeping in it. Does the output frequency sweep up and down and is 10 MHz somewhere in the sweep? It sweeps and is near 10 MHz, but I don't know if 10 MHz is within the sweeping range or just near it. Unfortunately I don't have another reference reliable enough to tell - that was why I bought this unit in the first place... Bobs suggestion in the other posts goes in the same direction. There is a trimmer cap and several trimpots on the board. I think I'll take a look at the board and try to figure out what exactly they are doing before trying to tweak them. The first column (Photocell DC voltage) shows that you've got lots of light from the lamp. That is why I have hope to fix this thing, a burnt out lamp would be hard to replace. Kind regards, Gerd ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
Probably, one of the best advantages of AVR over PIC is that with avr you can use the GCC compiler. Gcc of course is the compiler used everywhere and supports real ANSI C and has a good optimizer and it's free. So if you use AVR you can port most C code you find that was written for UNIX directly to the AVR As was said early in this thread, if you want to write in C, AVR is designed from the ground up for C. The PIC is older and has a very simple assembly language that is easy to learn. But the PIC C compilers are either expensive or crippled. The good thing about using gcc is that it also runs on the PC or Mac OS X so you can write test cases and run the code on your desktop. I lie to unit test the software in the larger computer using data from files to fully exercise the code before downloading it to the chip. Using the same compiler for the PC/Mac and the chip makes this easier. On Sun, May 26, 2013 at 10:34 AM, Orin Eman orin.e...@gmail.com wrote: On Sun, May 26, 2013 at 4:50 AM, Bob Camp li...@rtty.us wrote: Hi One of the original starting points was a free tool chain. Paying major money for a compiler is moving a bit far from that. You would have to do a *lot* of home projects to justify that cost. Indeed. I wouldn't pay commercial prices for a PIC C compiler for home projects. The 'Lite' version of SourceBoost that I actually bought is a whopping $5 and in spite of its RAM/ROM limitations, it's been good enough for me. If I ever sell a product that uses it, I'd need the commercial version at $150 - fair enough IMO. Orin. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
Well, its a matter of opinions I guess. The RPi has one UART which is also the console port, so so much for that, and 17 IOs in total from the link in the message below. On the other hand, the BeagleBone Black has 96 IOs including several UARTs. I have one of each at the moment, and it seems like the Pi is a better toy if one wants to hook up a keyboard and monitor, but the BBB is a better tool for embedded systems. I am also bothered by the closed nature of the RPi while the BBB is completely open. The RPi has sold many times more units, so there is more info and more resources also on the net. For a beginner wanting to learn, the RPi is probably a better choice. Didier David J Taylor david-tay...@blueyonder.co.uk wrote: The Pi has virtually no IOs, not good for any embedded system. The BeagleBone Black on the other hand has plentt of IOs Didier You can see the RPi I/O connections here: http://elinux.org/RPi_Low-level_peripherals#General_Purpose_Input.2FOutput_.28GPIO.29 Hardly virtually no IOs, and some of the pins can be re-assigned. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
In message CABbxVHvP0JmXo=ObnZUmtTH=7-ohixswixa0hy3svgo4gqd...@mail.gmail.com , Chris Albertson writes: Probably, one of the best advantages of AVR over PIC is that with avr you can use the GCC compiler. I recently had enough of all the trouble with both AVR and PIC chips and went ARM, which gives you way better C-language support than either has ever done. My current preference for random hacks is this one: https://www.olimex.com/Products/ARM/NXP/LPC-P1343/ This one has the neat feature that the firmware-load mode gives you are 32KB USB-stick with a single file called firmware.bin which means that even your grandmother can figure out how to update the firmware if need be... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
Hi Actually GCC does support *some* of the PICs. I'd prefer to go with a = PIC24 and run the free version of the Microchip compiler rather than GCC in this case. The optimization isn't quite as neat in the free Microchip compiler, but the price is right and the thing does work. Bob On May 26, 2013, at 3:19 PM, Chris Albertson albertson.ch...@gmail.com wrote: Probably, one of the best advantages of AVR over PIC is that with avr you can use the GCC compiler. Gcc of course is the compiler used everywhere and supports real ANSI C and has a good optimizer and it's free. So if you use AVR you can port most C code you find that was written for UNIX directly to the AVR As was said early in this thread, if you want to write in C, AVR is designed from the ground up for C. The PIC is older and has a very simple assembly language that is easy to learn. But the PIC C compilers are either expensive or crippled. The good thing about using gcc is that it also runs on the PC or Mac OS X so you can write test cases and run the code on your desktop. I lie to unit test the software in the larger computer using data from files to fully exercise the code before downloading it to the chip. Using the same compiler for the PC/Mac and the chip makes this easier. On Sun, May 26, 2013 at 10:34 AM, Orin Eman orin.e...@gmail.com wrote: On Sun, May 26, 2013 at 4:50 AM, Bob Camp li...@rtty.us wrote: Hi One of the original starting points was a free tool chain. Paying major money for a compiler is moving a bit far from that. You would have to do a *lot* of home projects to justify that cost. Indeed. I wouldn't pay commercial prices for a PIC C compiler for home projects. The 'Lite' version of SourceBoost that I actually bought is a whopping $5 and in spite of its RAM/ROM limitations, it's been good enough for me. If I ever sell a product that uses it, I'd need the commercial version at $150 - fair enough IMO. Orin. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Temex LPFRS-01 / LPRO rubidium reference repair
Hi Gerd, When it locks for a few seconds, make a note of the VCXO control voltage. Watch it as closely as you can during the lock period. Is it very near one end of the sweep range? Does it then drift off the end of the range when lock is lost? That behaviour would suggest that the VCXO has drifted out of range as Bob suggested. But if the voltage stays more towards the middle of the range (like 4D, 4C) that's not going to be the problem. You could also watch the output frequency since it tracks the frequency. Whichever is easier. If you can run it while it's open, check the temperatures of the lamp and the cavity as best you can. I see that they're specified in the manual. Also, check for obvious things like bad capacitors. Living next to that physics package must be a hard life for any capacitor! The negative terminal on the black electrolytic near the flex circuit looks a little strange, but that could just be a trick of the light. Ed On 5/26/2013 1:12 PM, Gerd v. Egidy wrote: Hi Ed, I don't have an LPFRS, but if I'm reading the manual correctly, the fourth column of numbers on the 'M' command (4D, 4C on your screen capture) is the VCXO control voltage. Shouldn't this be continuously sweeping up and down until it finds lock? You are right, it sweeps the control voltage up and down and the output frequency changes. But that is only happening during warmup. Once the unit had this short lock for a few seconds, it stops sweeping and does not start again even after losing the lock. Maybe a firmware issue not taking aging into account or something. The terminal output in my screenshot is from the time after the short lock, so you don't see any sweeping in it. Does the output frequency sweep up and down and is 10 MHz somewhere in the sweep? It sweeps and is near 10 MHz, but I don't know if 10 MHz is within the sweeping range or just near it. Unfortunately I don't have another reference reliable enough to tell - that was why I bought this unit in the first place... Bobs suggestion in the other posts goes in the same direction. There is a trimmer cap and several trimpots on the board. I think I'll take a look at the board and try to figure out what exactly they are doing before trying to tweak them. The first column (Photocell DC voltage) shows that you've got lots of light from the lamp. That is why I have hope to fix this thing, a burnt out lamp would be hard to replace. Kind regards, Gerd ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
Hi It is interesting how the various outfits sneak around the flash loader issue on their low end boards. Some of the dual CPU approaches I've seen actually have as much horsepower in the loader CPU as they do in the target. I'm not complaining about getting 2 usable cpu's for a bit over $10…. Bob On May 26, 2013, at 3:47 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message CABbxVHvP0JmXo=ObnZUmtTH=7-ohixswixa0hy3svgo4gqd...@mail.gmail.com , Chris Albertson writes: Probably, one of the best advantages of AVR over PIC is that with avr you can use the GCC compiler. I recently had enough of all the trouble with both AVR and PIC chips and went ARM, which gives you way better C-language support than either has ever done. My current preference for random hacks is this one: https://www.olimex.com/Products/ARM/NXP/LPC-P1343/ This one has the neat feature that the firmware-load mode gives you are 32KB USB-stick with a single file called firmware.bin which means that even your grandmother can figure out how to update the firmware if need be... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Temex LPFRS-01 / LPRO rubidium reference repair
Hi Ed, When it locks for a few seconds, make a note of the VCXO control voltage. Watch it as closely as you can during the lock period. Is it very near one end of the sweep range? Does it then drift off the end of the range when lock is lost? That behaviour would suggest that the VCXO has drifted out of range as Bob suggested. But if the voltage stays more towards the middle of the range (like 4D, 4C) that's not going to be the problem. You could also watch the output frequency since it tracks the frequency. Whichever is easier. Thanks for the tips. Will try that within the next few days. Also, check for obvious things like bad capacitors. Living next to that physics package must be a hard life for any capacitor! That was my first thought too. But I checked the capacitance and esr of all the al and tantalum caps - everything within reasonable values. Seems like they got really good quality ones and did their homework on this part of the design. Kind regards, Gerd ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
In message eed8cc97-4c42-4eed-93fa-b52073051...@rtty.us, Bob Camp writes: It is interesting how the various outfits sneak around the flash loader issue on their low end boards. Some of the dual CPU approaches I've seen actually have as much horsepower in the loader CPU as they do in the target. I'm not complaining about getting 2 usable cpu's for a bit over $10=85. In this case it's the same single chip doing the work. You can even access the subroutines from your own code, in case you want to implement a FAT-disk on the USB port. I generally use the USB port as a serial (CDC) device though. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
Hi Jason: I've done a number of PIC projects in assembly language because it like it. I like the 8 pin parts where they are all that's needed. But if you want to have USB or LAN connections then you'll need one of the much bigger parts or better already assembled boards. With a simpler part there's less to learn. Here's an example of a circuit that has 12 LEDs all driven from 4 PIC pins. http://www.prc68.com/I/PRC68COM.shtml#12LED This is an LCD clock and it uses the PIC 16F88 and is interrupt based, where assembly coding is mandatory because every machine cycle is critical in how the interrupts are handled. This is a time nuts clock where the external frequency reference is the heartbeat of the micro controller. The time can be set to a millisecond (the 1 PPS output is as good as the reference oscillator) and the date functions go back to fifteen hundred something as well as day of the week. http://www.prc68.com/I/PRC68COM.shtml#07092006 Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Jason Rabel wrote: I've decided I finally want to tackle learning how to use a PIC chip for some smaller projects. Can someone recommend me a good (and cheap) PIC, and possible some literature (be it a book or website)? I have a fairly recent willem eprom programmer that I'm hoping I can use. I don't know what all the features PICs have, but for my first project I would like to have it connected to a serial port on one of my Soekris' where it can grab info (i.e. the current time, or NTP/GPS info) and output that on a little LED display. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Follow-up question re: microcontroller families
Bah, 8 pins is way overkill for a fan controller, Microchip has a uC in a SOT-6 package that could probably do the job :) Didier Chris Albertson albertson.ch...@gmail.com wrote: But for many applications, the inevitable overhead (power, heat, external components, OS, etc) simply eliminates the gain of having a better/faster CPU. Sometimes I end up using a 6 or 8 pin PIC with only a few lines of code to to solve complex problems where a (F)PGA/CPLD design would be a lot of work and a 16/32bit microcontroller simply overkill. As it turns out there are a LOT more simple jobs than there are complex jobs. This is why they make and sel a lot motr 8-t controllers than they sell 32-bit controllers. For example I want to control the cooling fan for a rubidium oscillator's heat sink. I only need three pins, 1) the temperature sensor, 2) Fan tachometer pulse, fan voltage. A $1 tiny AVR 8-pin chip can handle this just fine and we are talking about 20 lines of code maybe after the pins are set up. Using an ARM and running an OS would be silly overkill. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
For some of the TI and NXP boards I have seen, the debug chip is clearly bigger than the target, probably due to the fact that the debut chip has USB and USB is typically only supported in the bigger chips. Didier Bob Camp li...@rtty.us wrote: Hi It is interesting how the various outfits sneak around the flash loader issue on their low end boards. Some of the dual CPU approaches I've seen actually have as much horsepower in the loader CPU as they do in the target. I'm not complaining about getting 2 usable cpu's for a bit over $10…. Bob On May 26, 2013, at 3:47 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message CABbxVHvP0JmXo=ObnZUmtTH=7-ohixswixa0hy3svgo4gqd...@mail.gmail.com , Chris Albertson writes: Probably, one of the best advantages of AVR over PIC is that with avr you can use the GCC compiler. I recently had enough of all the trouble with both AVR and PIC chips and went ARM, which gives you way better C-language support than either has ever done. My current preference for random hacks is this one: https://www.olimex.com/Products/ARM/NXP/LPC-P1343/ This one has the neat feature that the firmware-load mode gives you are 32KB USB-stick with a single file called firmware.bin which means that even your grandmother can figure out how to update the firmware if need be... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Follow-up question re: microcontroller families
bow...@gmail.com said: For making a blinking LEDs, it is hard to beat a 74LS74. However, a PIC, is probably less expensive! :) Thanks. :) I was going to send a wise-ass comment, but then I checked some numbers. Digikey, one-off DIP pricing: $0.62 SN74LS74 $0.55 PIC10F200 $0.33 SN74HC74 So technically you are correct, but only because you are picked an ancient technology. Besides, the '74 needs a clock while the PIC has an internal clock calibrated to 1%. I suspect what's going on is that the '74 is pad limited(*) so you are paying per-pad rather than per gate. The PIC only has 8 pins, so if it's close to pad limited it will be cheaper. The PIC10F200 has 3 output pins so it can blink 3 LEDs independently while the '74 only has 2 FFs. High volume (whole tape, 2-3K) prices are $0.34, 0.22, and 0.10 -- *) If you aren't familiar with pad-limited, it's a cool idea. Consider a chip that has N pins. Each pin needs a pad for the bond wire. Arrange those in a rectangle around the perimeter of your chip. That leaves a hole in the middle. Put your logic in there. If it doesn't fit, push the pads out until there is room. That makes your chip bigger and more expensive. If it fits with room leftover, you can add more logic for free. That's why low cost watches have so many features. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good (cheap) PIC chip choice for project?
-- Kenton A. Hoover ken...@nemersonhoover.org +14158305843 On Sunday, May 26, 2013 at 12:35, Didier Juges wrote: Well, its a matter of opinions I guess. The RPi has one UART which is also the console port, so so much for that, and 17 IOs in total from the link in the message below. On the other hand, the BeagleBone Black has 96 IOs including several UARTs. I have one of each at the moment, and it seems like the Pi is a better toy if one wants to hook up a keyboard and monitor, but the BBB is a better tool for embedded systems. I am also bothered by the closed nature of the RPi while the BBB is completely open. The RPi has sold many times more units, so there is more info and more resources also on the net. For a beginner wanting to learn, the RPi is probably a better choice. Didier David J Taylor david-tay...@blueyonder.co.uk wrote: The Pi has virtually no IOs, not good for any embedded system. The BeagleBone Black on the other hand has plentt of IOs Didier You can see the RPi I/O connections here: http://elinux.org/RPi_Low-level_peripherals#General_Purpose_Input.2FOutput_.28GPIO.29 Hardly virtually no IOs, and some of the pins can be re-assigned. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Follow-up question re: microcontroller families
Hi Ok, *but* Power? Mounting / circuit board? LED's? Resistors? Bypass caps? Control inputs? I believe I first learned how fast wire turns into something else when there's a short while JFK was president. That lesson in doing things quick and dirty has stuck with me. If a gizmo is going to keep running for quite a while you need to make it right. The original start to this thread was something that should work for years. The cost of wiring it up (PCB etc) will dwarf the cost of the CPU. Even with something simple (actually especially with something simple) all that stuff is going to add up. Even more so if you want the result to be reasonably rugged. Can you scramble wire it to a set of D cells and steal the LED's from a kid's toy? - sure. Does that make the rest of it free? - not so much. Doubly so when the kid comes looking for the toy :). Free parts can be a slippery thing. First simple test - can a total stranger (who keeps a neat house) get one for free as well? I can probably get all sorts of things for free if I use the work phone to make the call. That does not pass the test….. Second simple test - can I make 100 of them for a lower cost? Cost should go down as volume goes up…. If the objective is a time related gizmo (this being TimeNuts) simply making the LED blink can't be the the end of it. It's *got* to display the ADEV of the lunar orbit in morse code or some other highly useful thing. If it doesn't do something like that it's (possibly) off topic for the list. Turning this from a simple $ XX LED blinker to something much more complex probably adds less than 10% to the total cost. Optimizing one aspect of a design without considering the rest of it is rarely a good idea. Assuming your time is worthless generally leads to projects that don't complete. For that matter McDonalds will happily pay you minimum wage for your time. My apologies to those who enjoy hours of soldering mag wire in 3D constructs, most of us don't look at that as a learning experience the 100th time around. Most of the really fun stuff is done quickly, the rest of it - McDonalds is fun as well….Your time *always* has a cash value. That said - the 74LS74 isn't all that good at driving LED's - not a lot of current drive on those outputs. Same is true of the 74HC74. The 74AC74 is the one you want, 52 cents one up DIP at Digikey. Bob On May 26, 2013, at 8:17 PM, Hal Murray hmur...@megapathdsl.net wrote: bow...@gmail.com said: For making a blinking LEDs, it is hard to beat a 74LS74. However, a PIC, is probably less expensive! :) Thanks. :) I was going to send a wise-ass comment, but then I checked some numbers. Digikey, one-off DIP pricing: $0.62 SN74LS74 $0.55 PIC10F200 $0.33 SN74HC74 So technically you are correct, but only because you are picked an ancient technology. Besides, the '74 needs a clock while the PIC has an internal clock calibrated to 1%. I suspect what's going on is that the '74 is pad limited(*) so you are paying per-pad rather than per gate. The PIC only has 8 pins, so if it's close to pad limited it will be cheaper. The PIC10F200 has 3 output pins so it can blink 3 LEDs independently while the '74 only has 2 FFs. High volume (whole tape, 2-3K) prices are $0.34, 0.22, and 0.10 -- *) If you aren't familiar with pad-limited, it's a cool idea. Consider a chip that has N pins. Each pin needs a pad for the bond wire. Arrange those in a rectangle around the perimeter of your chip. That leaves a hole in the middle. Put your logic in there. If it doesn't fit, push the pads out until there is room. That makes your chip bigger and more expensive. If it fits with room leftover, you can add more logic for free. That's why low cost watches have so many features. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 9390 GPS RX
Ed, I'd unplugged the Rb from the counter and into the timer for measurement. During this time it had dropped out of lock again. That's why the Allan Deviation is so bad, it was sweeping. But I didn't realise as there was no counter attached! I need to connect something up to the 'lock' pin for a visual indication of lock to avoid further embarrassments.. I have cracked it open again and revisited the crystal board. I found that the centre frequency was a tad low so I upped C12 to 27pf (from 22pf) With 6v EFC and the trimmer cap in mid position its dead on 10Mhz. And I slowed down and waited (thanks Ed..) overnight to see if it drifted off anywhere else. But at 10Mhz it has stayed. I will reconnect EFC later on today (being a work day) when I get some time to move. I also have the sneaking suspicion the external adjustments have been 'got at' Looking at the trimmer pot through my mag lamp for c-field adjust, I can see a lot of scratches and wear. Hopefully the Oscillator current capacitor C11 and the temperature adjustment hasn't been touched. Anyway, Wish me luck ;) -marki -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Ed Palmer Sent: Monday, 27 May 2013 12:41 AM To: time-nuts@febo.com Subject: Re: [time-nuts] 9390 GPS RX Those readings look more like an OCXO than an Rb standard. Does it's behaviour as it locks match what I described earlier? You might also have your 5370 counter misconfigured. The 4.43 second Sample Interval suggests that you've got the Display Rate knob turned fully counterclockwise. make sure it's fully clockwise. I can probably give more detailed suggestions if you give me more detailed information on what you're doing and how the unit is responding. Ed On 5/25/2013 8:26 PM, Mark C. Stephens wrote: Hmm, Well looks like everything's checked out except, when I chucked it on time-lab the Allan deviation has gone out the window! Its measuring 6.17E-10 over 1 hour reading. Before I 'fixed' it was 4.99E-12 and I thought that was pretty average. I've attached the .tim's for your perusal. I have to hurry, I have a ton of stuff to get through and also find time to spend with the family too! -marks -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Ed Palmer Sent: Sunday, 26 May 2013 7:54 AM To: time-nuts@febo.com Subject: Re: [time-nuts] 9390 GPS RX On 5/25/2013 12:43 AM, Mark C. Stephens wrote: Hey Ed, Just knocked up a temperature sensor with a Dallas single wire temperature sensor thingy, a pic and an LCD display. So, I will know for sure I am hitting the xtal turning point. I figured you had been right about everything so perhaps my temperature gun was out. It's probably a handy bit of kit to have, because no doubt I have a couple of ovens here that are playing up ad some sort of accurate temperature measurement and logging would be a handy bit of kit to have. It spits out the time and temperature reading once per second via a serial interface as well as displays in on the LCD.. I had already sort of written the code 10 years ago, just hadn't gotten around to finishing the hardware. :) A few changes here and there for the pic pin out and it worked! Just going through the warm-up cycle now, I expect an hour should do it. Seems to be heating that crystal very slowly. I think there still may be a problem around that wee transistor that limits the current to the heater transistor. Or perhaps by putting the right value 6K81 resistor and a new op-amp changed the dynamics and I may need to revisit R8. I have checked the PSU, its 17.3v spot on. I checked the temperature after an hour and it was only 58 degrees ): I stuck a resistance box across R8 and adjusted until I got ~79 on my temperature meter. The resistance is 680R which seems very low to me, but not outside the circuit specifications. As you change R8, watch the frequency of the oscillator as it changes. When your temperature meter shows 79C, is the frequency at its lowest point? Although the frequency changes with age, I've never seen anything to suggest that the turning point changes with age. Anyone reading this, please correct me if I'm wrong. Regardless of the actual temperature, you want to adjust the crystal temperature so that you hit the turning point. For an AT crystal, that will give you the lowest frequency. Once you get to the turning point you will see if you will be able to get it working by changing the capacitors. For test purposes, if the crystal frequency is only slightly out of range, change the temperature with R8 until you can get to 10 MHz. But appear to have dug myself into a hole. It looks like the hole was already there. But you kind of jumped in with both feet! :) I disconnected the EFC as per the manual and hooked up a 10K 'Pot' across the 17.3v supply and the wiper
Re: [time-nuts] 9390 GPS RX
On 5/26/2013 8:24 PM, Mark C. Stephens wrote: Ed, I'd unplugged the Rb from the counter and into the timer for measurement. During this time it had dropped out of lock again. That's why the Allan Deviation is so bad, it was sweeping. But I didn't realise as there was no counter attached! I need to connect something up to the 'lock' pin for a visual indication of lock to avoid further embarrassments.. I've got manuals for both the FRK and the 'FRK (H or L)'. The FRK says that the lock input can handle up to 70V @ 50 ma. The other one doesn't say. You should be able to run an LED with a dropping resistor from the +24 supply. I have cracked it open again and revisited the crystal board. I found that the centre frequency was a tad low so I upped C12 to 27pf (from 22pf) With 6v EFC and the trimmer cap in mid position its dead on 10Mhz. Remember that it doesn't have to be dead center. After all, that's why the thing sweeps in the first place. It's looking for the signal and it will find it if it's anywhere in the sweep range. And I slowed down and waited (thanks Ed..) overnight to see if it drifted off anywhere else. But at 10Mhz it has stayed. Very nice! :) More thought, less action. Move as though you're defusing a bomb. Ideally, you know what you want to do, why (with at least two seperate tests to confirm your reasoning), and what should happen when you make the change. Adjustments are bad enough, be triple sure before you touch the soldering iron. Yes, it's overkill for most situations, but if major dollars or an irreplaceable device are at stake, it will pay dividends in the long term. I will reconnect EFC later on today (being a work day) when I get some time to move. Work? What is this Work thing you speak of? Oh, yes, I think I do have some vague recollection from years past. I think I tried it but didn't care for it. :) I also have the sneaking suspicion the external adjustments have been 'got at' Looking at the trimmer pot through my mag lamp for c-field adjust, I can see a lot of scratches and wear. I wouldn't be surprised to find that someone played with the external adjustment in a misguided attempt to compensate for the crystal drift. Totally ineffective. The C-field is at the wrong end of the system. Hopefully the Oscillator current capacitor C11 and the temperature adjustment hasn't been touched. You mean for the lamp? They're pretty hard to get at. I had to adjust the lamp temperature on one unit and had a devil of a time finding a screwdriver that could reach it. The reading on the lamp voltage monitor will tell you if those adjustments are correct. Remember, move slowly and carefully. :) Anyway, Wish me luck ;) Always :), Ed ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
