Re: [time-nuts] ARM boards for low-cost GPSDOs
Hi Here’s the issue about “big powerful 32 bit ARM processors”…. At the chip level (as in no board, just the bare part to solder down) their are many parts below $1 and some below $0.50 in reasonable quantity (say 10K). It’s hard to find a useful MCU of any sort below $0.25, so the “premium” for an ARM is not very large. Depending on what you need for i/o, the ARM may / may not be lower priced than the alternative. In a *lot* of cases it is the low price option. There are many flavors of ARM and many competing parts, so doing a full matrix to compare them all is a massive undertaking. Indeed a Coretex M0 with 32K of flash is not the same thing as an M4 or something bigger still. There are a lot of flavors of ARM. At the semiconductor level, none of the manufacturers are going to state it clearly, but it’s becoming more and more clear. The support for (and enhancement of) chips that are not based on ARM is going to dry up. It’s happening already if you watch the little details. It will be happening more and more as time marches on. It will be *very* tough for an MCU over about $1.00 a chip (at say 10K pcs) to compete with the ARM parts going forward outside niche markets (like DSP). No, it’s not going to happen overnight. It will take a number of years for things to work out. ——— So why do a GPSDO on an ARM - They have staying power. The bang for the buck is there. There are a lot of cheap boards out there with them already set up and running on them. Nobody big is going back to leaded parts. Semiconductor guys follow the big users. The future of “home project” work with CPU’s is to use a cheap board rather than a chip. The prices of the boards will just keep coming down, they are not going to go up…. I can’t buy the parts on a $10 board for $30, let alone put them all together. Pick a board and go with it. Put your *stuff* on a second board and plug them together. Cheaper, faster, easier than DIY. You get USB / Ethernet / whatever thrown in. With the right board (chip) you get flexible clocks and PLL’s that make the whole process a lot easier. What’s not to like? Well yes, you need to dig into a tool chain. They either are free, or are going to be free fairly soon now. There are even web based tools to do the code stuff (mbed). You can’t quite write it for one chip and drop it on another one blindly. You do get locked (a bit) into your chip choice. All in all, far more advantages than disadvantages. Bob On Apr 10, 2014, at 8:11 PM, Chris Albertson albertson.ch...@gmail.com wrote: I'm thinking about good reasons to build a GPSDO using something as big and powerful as a 32-bit ARM processor.I think the reason is that you are not really building a GPSDO but some other device that just happens to have a GPSDO inside of it. For example you want to build a laser range finder and you need to measure time of flight delay. You'd need a very good clock and while you are at it why not discipline the clock with GPS. I could think of some radio experiments where I would want pairs of receivers with their local oscillators running in phase but many miles apart, so I'd build a GPSDO into the radio.The ARM would support running the GPSDO, the bigger application and also remote access over the network or Internet. Today people mostly will build a stand alone GPSDO in a dedicated box and then connect the 10MHZ output to whatever is needed but now as we have seen, you can build a GPSDO completely in software, if your project already has a computer then you can run a GPSDO inside an interrupt handler as a background task. Adding GPSDO functionality to an existing product is almost trivially simple, just $2 in parts and some software if you already have a CPU and OCXO as part of your system. Placing the GPSDO inside the product means the gpsdo can run at a frequency that is more useful and needs no conversion. So you can have the GPS control a 23 Mhz crystal if that is what your laser rangefinder needs. Now that the cost of a GPSDO has fallen to $3 you can build them into everything. It no longer needs to be a shared device. ___ 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] ARM boards for low-cost GPSDOs
Bob 100% totally agree and I am seeing the same thing happening. It has to do with the lower power consumption. When you see Intel scrambling again to take some share thats the biggest clue there is that a shift is on the way. But enough of that I said my piece far earlier in the chain. We sure are lucky to have this stuff on a board to use for what I consider to be inexpensive. And I don't have to solder the darned things! Best regards Paul WB8TSL On Sat, Apr 12, 2014 at 12:23 PM, Bob Camp li...@rtty.us wrote: Hi Here's the issue about big powerful 32 bit ARM processors At the chip level (as in no board, just the bare part to solder down) their are many parts below $1 and some below $0.50 in reasonable quantity (say 10K). It's hard to find a useful MCU of any sort below $0.25, so the premium for an ARM is not very large. Depending on what you need for i/o, the ARM may / may not be lower priced than the alternative. In a *lot* of cases it is the low price option. There are many flavors of ARM and many competing parts, so doing a full matrix to compare them all is a massive undertaking. Indeed a Coretex M0 with 32K of flash is not the same thing as an M4 or something bigger still. There are a lot of flavors of ARM. At the semiconductor level, none of the manufacturers are going to state it clearly, but it's becoming more and more clear. The support for (and enhancement of) chips that are not based on ARM is going to dry up. It's happening already if you watch the little details. It will be happening more and more as time marches on. It will be *very* tough for an MCU over about $1.00 a chip (at say 10K pcs) to compete with the ARM parts going forward outside niche markets (like DSP). No, it's not going to happen overnight. It will take a number of years for things to work out. -- So why do a GPSDO on an ARM - They have staying power. The bang for the buck is there. There are a lot of cheap boards out there with them already set up and running on them. Nobody big is going back to leaded parts. Semiconductor guys follow the big users. The future of home project work with CPU's is to use a cheap board rather than a chip. The prices of the boards will just keep coming down, they are not going to go up I can't buy the parts on a $10 board for $30, let alone put them all together. Pick a board and go with it. Put your *stuff* on a second board and plug them together. Cheaper, faster, easier than DIY. You get USB / Ethernet / whatever thrown in. With the right board (chip) you get flexible clocks and PLL's that make the whole process a lot easier. What's not to like? Well yes, you need to dig into a tool chain. They either are free, or are going to be free fairly soon now. There are even web based tools to do the code stuff (mbed). You can't quite write it for one chip and drop it on another one blindly. You do get locked (a bit) into your chip choice. All in all, far more advantages than disadvantages. Bob On Apr 10, 2014, at 8:11 PM, Chris Albertson albertson.ch...@gmail.com wrote: I'm thinking about good reasons to build a GPSDO using something as big and powerful as a 32-bit ARM processor.I think the reason is that you are not really building a GPSDO but some other device that just happens to have a GPSDO inside of it. For example you want to build a laser range finder and you need to measure time of flight delay. You'd need a very good clock and while you are at it why not discipline the clock with GPS. I could think of some radio experiments where I would want pairs of receivers with their local oscillators running in phase but many miles apart, so I'd build a GPSDO into the radio.The ARM would support running the GPSDO, the bigger application and also remote access over the network or Internet. Today people mostly will build a stand alone GPSDO in a dedicated box and then connect the 10MHZ output to whatever is needed but now as we have seen, you can build a GPSDO completely in software, if your project already has a computer then you can run a GPSDO inside an interrupt handler as a background task. Adding GPSDO functionality to an existing product is almost trivially simple, just $2 in parts and some software if you already have a CPU and OCXO as part of your system. Placing the GPSDO inside the product means the gpsdo can run at a frequency that is more useful and needs no conversion. So you can have the GPS control a 23 Mhz crystal if that is what your laser rangefinder needs. Now that the cost of a GPSDO has fallen to $3 you can build them into everything. It no longer needs to be a shared device. ___ 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] ARM boards for low-cost GPSDOs
Hi I’ve been working with some friends on an ARM based Arduino project. The support for ARM in the Arduino tool chain is still not really up to speed. It’s actually been faster / easier to take the stuff we need over to another board and tool chain than to fight through all of the gotchas within the Arduino / ARM world. The stuff is free / easy just about any way you do it. At the chip level, the ARM’s have already overtaken many / most of the AVR’s that you would be using. Bob On Apr 12, 2014, at 3:23 PM, Chris Albertson albertson.ch...@gmail.com wrote: I have to agree. At the hobby level I've been using board level products. Typically some guy in China buys the chips and any needed passive parts and builds a PCB. Almost always the PCB will have a row of holes on the edge to fit a 0.1 header strip. The board with shipping sells cheaper than the price of the parts. (The Chinese sellers are using private mailing brokers who can aggregate large numbers of packages onto pallets, ship the pallets via low cost carries to a warehouse near a US post office. The packages are zip-code sorted and dropped into the USPO's pre-sorted bulk-mail system for just a few cents per package.) I think what prevents many people from using some uP parts is the tools. In the past they were complex but Arduino fixed that. They made is VERY easy to get started and really set the bar for others. Everyone else is catching up. There really WAS a high cost of entry back when you needed to know how to edit text and send it to a compiler then a loader and burn PROMs using special prom burner hardware. All that complexity is now gone. Notice that new Arduino boards are ARM based and if you were foresightful enough to only use the features that are documented for Arduino your software can move directly to the new ARM board. Many hobby programmers should not notice the difference when a CPU is changed. They are writing in C/C++ Today at the retail level AVR based Arduino is much less expensive. You can buy one with shipping for under $4 and you can use a 9V radio battery for a power supply. I've bought some for under $3.But, yes some day ARM will move down into this price point. On Sat, Apr 12, 2014 at 9:23 AM, Bob Camp li...@rtty.us wrote: Hi Here's the issue about big powerful 32 bit ARM processors At the chip level (as in no board, just the bare part to solder down) their are many parts below $1 and some below $0.50 in reasonable quantity (say 10K). It's hard to find a useful MCU of any sort below $0.25, so the premium for an ARM is not very large. Depending on what you need for i/o, the ARM may / may not be lower priced than the alternative. In a *lot* of cases it is the low price option. There are many flavors of ARM and many competing parts, so doing a full matrix to compare them all is a massive undertaking. Indeed a Coretex M0 with 32K of flash is not the same thing as an M4 or something bigger still. There are a lot of flavors of ARM. At the semiconductor level, none of the manufacturers are going to state it clearly, but it's becoming more and more clear. The support for (and enhancement of) chips that are not based on ARM is going to dry up. It's happening already if you watch the little details. It will be happening more and more as time marches on. It will be *very* tough for an MCU over about $1.00 a chip (at say 10K pcs) to compete with the ARM parts going forward outside niche markets (like DSP). No, it's not going to happen overnight. It will take a number of years for things to work out. -- So why do a GPSDO on an ARM - They have staying power. The bang for the buck is there. There are a lot of cheap boards out there with them already set up and running on them. Nobody big is going back to leaded parts. Semiconductor guys follow the big users. The future of home project work with CPU's is to use a cheap board rather than a chip. The prices of the boards will just keep coming down, they are not going to go up I can't buy the parts on a $10 board for $30, let alone put them all together. Pick a board and go with it. Put your *stuff* on a second board and plug them together. Cheaper, faster, easier than DIY. You get USB / Ethernet / whatever thrown in. With the right board (chip) you get flexible clocks and PLL's that make the whole process a lot easier. What's not to like? Well yes, you need to dig into a tool chain. They either are free, or are going to be free fairly soon now. There are even web based tools to do the code stuff (mbed). You can't quite write it for one chip and drop it on another one blindly. You do get locked (a bit) into your chip choice. All in all, far more advantages than disadvantages. Bob On Apr 10, 2014, at 8:11 PM, Chris Albertson albertson.ch...@gmail.com wrote: I'm thinking about good reasons to build a GPSDO using something as big and
Re: [time-nuts] ARM boards for low-cost GPSDOs
On 4/12/14, 12:50 PM, Bob Camp wrote: Hi I’ve been working with some friends on an ARM based Arduino project. The support for ARM in the Arduino tool chain is still not really up to speed. It’s actually been faster / easier to take the stuff we need over to another board and tool chain than to fight through all of the gotchas within the Arduino / ARM world. The stuff is free / easy just about any way you do it. The teensyduino stuff from PJRC is adding quite a lot to the ARM world within the Arduino IDE. It is true that for some of the onchip peripherals, there might not be full support, and you have to do some register writing, etc. At the chip level, the ARM’s have already overtaken many / most of the AVR’s that you would be using. ___ 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] ARM boards for low-cost GPSDOs
Hi If you are doing a GPSDO, you probably are playing a lot with things like clock trees and PLL frequencies. There are other free toolchains (often vendor specific) that can make this *much* easier. Not all ARM’s are the same in terms of clocking, so it’s not a one size fits all sort of thing. Bob On Apr 12, 2014, at 7:01 PM, Jim Lux jim...@earthlink.net wrote: On 4/12/14, 12:50 PM, Bob Camp wrote: Hi I’ve been working with some friends on an ARM based Arduino project. The support for ARM in the Arduino tool chain is still not really up to speed. It’s actually been faster / easier to take the stuff we need over to another board and tool chain than to fight through all of the gotchas within the Arduino / ARM world. The stuff is free / easy just about any way you do it. The teensyduino stuff from PJRC is adding quite a lot to the ARM world within the Arduino IDE. It is true that for some of the onchip peripherals, there might not be full support, and you have to do some register writing, etc. At the chip level, the ARM’s have already overtaken many / most of the AVR’s that you would be using. ___ 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] ARM boards for low-cost GPSDOs
Hi All, I've used the STM32F4 for a few projects, and was considering it for a time tagger for a DMTD system. I have a question about the clocking though that someone may be able to help me with. The 32F4 (like lots of similar ARMs) uses a PLL to generate the internal clocks from much lower frequency clock or crystal. Has anyone quantified the stability of the synthesised clock? Thanks, david On 11/04/2014 8:02 AM, Alberto di Bene wrote: On 4/10/2014 11:38 PM, Hal Murray wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple Arduino like setup rather than something that runs Linux. The idea is to get 32 bit counters so a bunch of the recent discussion can be ingnored. == I can't recommend warmly enough the Discovery board from STM. It sports a Cortex ARM M4F that can run at 180 MHz, has a native IEEE compliant floating point core, 2MB flash and 256 kB RAM, and a wealth of interesting peripherals on chip, TFT display touch enabled included. And at 23.52 USD is cheaper than a much less powerful Arduino... I implemented on it a fully featured SDR, without using any opsys, talking directly to the bare metal using the Keil IDE/compiler. A joy to use. Look here : http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/LN1848/PF259090 73 Alberto I2PHD --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.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] ARM boards for low-cost GPSDOs
David we may be drifting from Hals thread. So don't want to do that. I looked at the system and its governed by the xtal they use. Granted its cheap and totally in an uncontrolled environment. Mine typically is +.79 ppm at 1 Mhz. Semi consistent. Its really easy to bypass that xtal and to inject some higher quality source and reap those benefits. They have little pads and such to allow it. Regards Paul WB8TSL On Fri, Apr 11, 2014 at 7:49 AM, davidh dho...@gmail.com wrote: Hi All, I've used the STM32F4 for a few projects, and was considering it for a time tagger for a DMTD system. I have a question about the clocking though that someone may be able to help me with. The 32F4 (like lots of similar ARMs) uses a PLL to generate the internal clocks from much lower frequency clock or crystal. Has anyone quantified the stability of the synthesised clock? Thanks, david On 11/04/2014 8:02 AM, Alberto di Bene wrote: On 4/10/2014 11:38 PM, Hal Murray wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple Arduino like setup rather than something that runs Linux. The idea is to get 32 bit counters so a bunch of the recent discussion can be ingnored. == I can't recommend warmly enough the Discovery board from STM. It sports a Cortex ARM M4F that can run at 180 MHz, has a native IEEE compliant floating point core, 2MB flash and 256 kB RAM, and a wealth of interesting peripherals on chip, TFT display touch enabled included. And at 23.52 USD is cheaper than a much less powerful Arduino... I implemented on it a fully featured SDR, without using any opsys, talking directly to the bare metal using the Keil IDE/compiler. A joy to use. Look here : http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/LN1848/PF259090 73 Alberto I2PHD --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.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. ___ 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] ARM boards for low-cost GPSDOs
dho...@gmail.com said: The 32F4 (like lots of similar ARMs) uses a PLL to generate the internal clocks from much lower frequency clock or crystal. Has anyone quantified the stability of the synthesised clock? I'm not familiar with the 32F4, but most of the SOC type ARM chips have ways to generate clocks by dividing the main clock and a way to feed those clocks out a pin. So collecting data would be a small amount of code to set things up and then your normal clock analysis setup. There would be additional noise depending upon the package (and board layout) and how much is going on in the chip, mostly how often other output pins are changing, especially the nearby ones. -- 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] ARM boards for low-cost GPSDOs
Does anybody have a favorite low-cost ARM board? I'm looking for a simple Arduino like setup rather than something that runs Linux. The idea is to get 32 bit counters so a bunch of the recent discussion can be ingnored. -- 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] ARM boards for low-cost GPSDOs
Take a look at http://www.pjrc.com/teensy/. Regards, Edésio On Thu, Apr 10, 2014 at 02:38:10PM -0700, Hal Murray wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple Arduino like setup rather than something that runs Linux. The idea is to get 32 bit counters so a bunch of the recent discussion can be ingnored. -- 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] ARM boards for low-cost GPSDOs
Hal I sent you a message on the STM arm board and attached the speck sheet. Its 215KB so it may not come through. Just look up the STM discovery kit. Its $21 in the US. Lots of good stuff counters IO and and such Regards Paul WB8TSL On Thu, Apr 10, 2014 at 5:38 PM, Hal Murray hmur...@megapathdsl.net wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple Arduino like setup rather than something that runs Linux. The idea is to get 32 bit counters so a bunch of the recent discussion can be ingnored. -- 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] ARM boards for low-cost GPSDOs
On 4/10/2014 11:38 PM, Hal Murray wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple Arduino like setup rather than something that runs Linux. The idea is to get 32 bit counters so a bunch of the recent discussion can be ingnored. == I can't recommend warmly enough the Discovery board from STM. It sports a Cortex ARM M4F that can run at 180 MHz, has a native IEEE compliant floating point core, 2MB flash and 256 kB RAM, and a wealth of interesting peripherals on chip, TFT display touch enabled included. And at 23.52 USD is cheaper than a much less powerful Arduino... I implemented on it a fully featured SDR, without using any opsys, talking directly to the bare metal using the Keil IDE/compiler. A joy to use. Look here : http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/LN1848/PF259090 73 Alberto I2PHD --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.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] ARM boards for low-cost GPSDOs
Alberto did the job of reposting the information for me. Thank you. Hal take a look its impressive for $21. Regards Paul WB8TSL On Thu, Apr 10, 2014 at 6:02 PM, Alberto di Bene dib...@usa.net wrote: On 4/10/2014 11:38 PM, Hal Murray wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple Arduino like setup rather than something that runs Linux. The idea is to get 32 bit counters so a bunch of the recent discussion can be ingnored. == I can't recommend warmly enough the Discovery board from STM. It sports a Cortex ARM M4F that can run at 180 MHz, has a native IEEE compliant floating point core, 2MB flash and 256 kB RAM, and a wealth of interesting peripherals on chip, TFT display touch enabled included. And at 23.52 USD is cheaper than a much less powerful Arduino... I implemented on it a fully featured SDR, without using any opsys, talking directly to the bare metal using the Keil IDE/compiler. A joy to use. Look here : http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/LN1848/PF259090 73 Alberto I2PHD --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.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. ___ 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] ARM boards for low-cost GPSDOs
On 04/10/2014 05:38 PM, Hal Murray wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple Arduino like setup rather than something that runs Linux. The idea is to get 32 bit counters so a bunch of the recent discussion can be ingnored. Another endorsement for a STM32 Discovery board from me. The F3 and F4 ones have plenty of peripherals to play with and they're cheap as dirt. For a concrete example of how the kind of PPS capture that's being discussed would pan out on STM32, here's mine: https://github.com/mtharp/laureline-firmware/blob/master/src/ppscapture.c The timers are 16-bit but I extend it to 64 bits in software. When the timer rolls over I add 65536 to the software variable mono_epoch. At both the rollover and at the half-way mark I poll the timer-capture peripheral to see if it captured a PPS. It's polled twice per period to ensure that I can disambiguate whether the captured value came from the current period or the previous one. The result is a 64-bit timestamp from the free-running clock, and it's completely glitch-free and not affected by interrupt latency in any way. The same timer is also used as the base for the UTC clock, which is a software-disciplined clock like you'd find in any OS kernel. That makes it easy to compare the phase of the PPS captured to the nearest UTC second and feed into the PLL. Not as interesting for a GPSDO where you need to actually steer a hardware oscillator, but useful nonetheless. ___ 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] ARM boards for low-cost GPSDOs
The timers are 16-bit but I extend it to 64 bits in software. When the timer rolls over I add 65536 to the software variable mono_epoch. At BTW, its possible to extend timer to 64 bit using special feature of ST32. Its when one timer (master), controlling the other timer(s) (slaves). See following app. note, for example: http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/CD00165509.pdf Also, the examples which coming with peripheral library helps a lot ! I was using PIC and Freescale before. All my recent project is on ST32. But instead of Discovery board I would prefer bare board with MCU from auction site. JUst because its gives me more control. ;-) -- WBW, V.P. ___ 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] ARM boards for low-cost GPSDOs
First, the Arduino can count cycles just fine. Look at the C code I posted, it is all of about two dozen lines. It is intentionally simplistic but seem seems to work. This discussion is about how I might be able to remove about a half dozen lines. I'd bet you a bunch the ARM would NOT be simpler. I would not go with the ARM process just to save having to count cary-overs. There is a great advantage to building a GPSDO in an ARM and a REALLY great advantage to building on with a Beagle Board. Because you could also build an NTP server on the same platform and time transfer to the NTP server would be near perfect. The BB could run a web server too and WiFi stack so you could control the entire GPSDO/NTP Server with a wireless cell phone or tablet. You can remotely log in to your controller using SSH. It's gross overkill but the price is only about $50.The Raspberry Pi is not a whole loot different. If you want a simple, low cost ARM development system there are three that I'd look at. 1) The teensy. cost is $19 and it is the same size as the Arduino mini http://www.pjrc.com/store/teensy3.html Adafruit and Sparkfun also sell this same board. 2) The new Arduino Due is based on ARM and runs the same software environment as the AVR based Arduino. but of course is much more powerful and costs more. Lots of support and all your Arduino code will mostly still work. http://arduino.cc/en/Main/ArduinoBoardDue 3) TI sells a Launch Pad at a very good price, about $13 and it is VERY well supported with training materials, software and so on. I'm sure TI iix taking a loss on these. They can't be making money at $13 This is a great value. http://www.ti.com/ww/en/launchpad/launchpads-tivac.html#tabs On Thu, Apr 10, 2014 at 2:38 PM, Hal Murray hmur...@megapathdsl.net wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple Arduino like setup rather than something that runs Linux. The idea is to get 32 bit counters so a bunch of the recent discussion can be ingnored. -- 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. -- 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] ARM boards for low-cost GPSDOs
At 04:38 PM 4/10/2014, Hal Murray wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple I'm using one of the TI Tiva C series Launchpads for my ovenized PC xtal project. ~$13, 80 MHz Cortex M4F (f=floating point), 256 kB flash, 32kB ram, 12 bit ADCs, 32 bit timers (some can be split into 16 bit, some can chain to 64 bit). http://www.ti.com/ww/en/launchpad/launchpads-tivac-ek-tm4c123gxl.html#tabs I like it a lot (but I've not done much with it, certainly nothing exciting with the timers), but those STM32 discovery boards sound *really* nice, too. -- newell N5TNL ___ 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] ARM boards for low-cost GPSDOs
What I can say about all of this is the compute power on small boards for little money power and heat is simply crazy. I have the launchpads also and now there is a new one complete with Ethernet for $21. Then we have all sorts of tool chains for free. Pretty exciting times. So Hal lots of good stuff to be had that do indeed make the types of things we work on easier. Reagrds Paul WB8TSL On Thu, Apr 10, 2014 at 7:47 PM, Scott Newell newell+timen...@n5tnl.comwrote: At 04:38 PM 4/10/2014, Hal Murray wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple I'm using one of the TI Tiva C series Launchpads for my ovenized PC xtal project. ~$13, 80 MHz Cortex M4F (f=floating point), 256 kB flash, 32kB ram, 12 bit ADCs, 32 bit timers (some can be split into 16 bit, some can chain to 64 bit). http://www.ti.com/ww/en/launchpad/launchpads-tivac-ek-tm4c123gxl.html#tabs I like it a lot (but I've not done much with it, certainly nothing exciting with the timers), but those STM32 discovery boards sound *really* nice, too. -- newell N5TNL ___ 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] ARM boards for low-cost GPSDOs
Some of the STM DIscovery boards are less than $10... search mouser.com for STM Discovery ___ 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] ARM boards for low-cost GPSDOs
I'm thinking about good reasons to build a GPSDO using something as big and powerful as a 32-bit ARM processor.I think the reason is that you are not really building a GPSDO but some other device that just happens to have a GPSDO inside of it. For example you want to build a laser range finder and you need to measure time of flight delay. You'd need a very good clock and while you are at it why not discipline the clock with GPS. I could think of some radio experiments where I would want pairs of receivers with their local oscillators running in phase but many miles apart, so I'd build a GPSDO into the radio.The ARM would support running the GPSDO, the bigger application and also remote access over the network or Internet. Today people mostly will build a stand alone GPSDO in a dedicated box and then connect the 10MHZ output to whatever is needed but now as we have seen, you can build a GPSDO completely in software, if your project already has a computer then you can run a GPSDO inside an interrupt handler as a background task. Adding GPSDO functionality to an existing product is almost trivially simple, just $2 in parts and some software if you already have a CPU and OCXO as part of your system. Placing the GPSDO inside the product means the gpsdo can run at a frequency that is more useful and needs no conversion. So you can have the GPS control a 23 Mhz crystal if that is what your laser rangefinder needs. Now that the cost of a GPSDO has fallen to $3 you can build them into everything. It no longer needs to be a shared device. ___ 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] ARM boards for low-cost GPSDOs
Chris Thats what I am saying the compute power is amazing even with arduinos. I find it crazy to trip over limitations when this technology is available. So yes I hope to use the STM board to solve the WWVB BPSK issue. At $21 its a so what for me $ wise at least. I purchased 3 just because they do appear pretty handy. The same with the launchpads. Now I went out to the TI site and they have additional launch pad eval kits. All on nice boards just like the STM evals. Hope this helps Hal who started the thread. I have said enough and on to that old Forth code. Regards Paul WB8TSL On Thu, Apr 10, 2014 at 8:11 PM, Chris Albertson albertson.ch...@gmail.comwrote: I'm thinking about good reasons to build a GPSDO using something as big and powerful as a 32-bit ARM processor.I think the reason is that you are not really building a GPSDO but some other device that just happens to have a GPSDO inside of it. For example you want to build a laser range finder and you need to measure time of flight delay. You'd need a very good clock and while you are at it why not discipline the clock with GPS. I could think of some radio experiments where I would want pairs of receivers with their local oscillators running in phase but many miles apart, so I'd build a GPSDO into the radio.The ARM would support running the GPSDO, the bigger application and also remote access over the network or Internet. Today people mostly will build a stand alone GPSDO in a dedicated box and then connect the 10MHZ output to whatever is needed but now as we have seen, you can build a GPSDO completely in software, if your project already has a computer then you can run a GPSDO inside an interrupt handler as a background task. Adding GPSDO functionality to an existing product is almost trivially simple, just $2 in parts and some software if you already have a CPU and OCXO as part of your system. Placing the GPSDO inside the product means the gpsdo can run at a frequency that is more useful and needs no conversion. So you can have the GPS control a 23 Mhz crystal if that is what your laser rangefinder needs. Now that the cost of a GPSDO has fallen to $3 you can build them into everything. It no longer needs to be a shared device. ___ 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] ARM boards for low-cost GPSDOs
My nice one was $9 and now they are $14. price gouging. ;-) Regards Paul WB8TSL On Thu, Apr 10, 2014 at 7:58 PM, Mark Sims hol...@hotmail.com wrote: Some of the STM DIscovery boards are less than $10... search mouser.comfor STM Discovery ___ 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] ARM boards for low-cost GPSDOs
On Thu, Apr 10, 2014 at 4:40 PM, Chris Albertson albertson.ch...@gmail.comwrote: 3) TI sells a Launch Pad at a very good price, about $13 and it is VERY well supported with training materials, software and so on. I'm sure TI iix taking a loss on these. They can't be making money at $13 This is a great value. http://www.ti.com/ww/en/launchpad/launchpads-tivac.html#tabs edX have been running a course on embedded systems using a TI LaunchPad. I've been doing it for fun using the TI Stellaris LM4F120 LaunchPad: https://www.edx.org/course/utaustinx/utaustinx-ut-6-01x-embedded-systems-1172 If that doesn't work, got to www.edx.org and look for courses from UTAustinX. It's a pretty good introduction to programming these things, using the Keil development environment. They have programmed addons to the IDE to grade your work both in simulation and on real hardware. A bit late to start on it, but no actual deadlines have passed... yet. 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] ARM boards for low-cost GPSDOs
On 4/10/14 2:38 PM, Hal Murray wrote: Does anybody have a favorite low-cost ARM board? I'm looking for a simple Arduino like setup rather than something that runs Linux. The idea is to get 32 bit counters so a bunch of the recent discussion can be ingnored. teensy3.1.. ARM Cortex M0 in the context of a Freescale K20 Kinetis chip. Arduino compatible (uses the IDE, etc.), $20. 72 MHz clock, etc. ___ 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.
