Re: [time-nuts] FE-5680A DDS Board/PIC Code
On Thu, Feb 28, 2013 at 03:49:55AM +0100, Magnus Danielson wrote: On 02/18/2013 10:32 PM, Herbert Poetzl wrote: [ lot of stuff zapped ] It would be interesting if fractional resolution of the DDS would be developed using the PHASE interface. As PHASE ripples, a carry needs to be sent into the phase accumulator of the AD9830, or alternatively fiddling the frequency value would help. While continuously adjusting the phase (via PHASEx) would probably work, I was more thinking about changing the FREQx values, which contribute to the phase accumulator. IMHO this should give a much better result than the abrupt phase changes and thus a smoother output with less unwanted noise. One approach might be to set FREQ0 to the last value below the desired frequency and FREQ1 to the first value above (i.e. FREQ0 + 1) and then toggle FSELECT in a pattern to match the fractional part. FSELECT has a pipeline delay of 6 MCLK, but that doesn't matter much if you do micro adjustments and FSELECT can be changed at any time without causing any discontinuity. And the best part: FSELECT is a small cable soldered onto the AD9830 which can easily be rerouted to the PIC. But I haven't found the spare time to dig into yet ... best, Herbert Anyway, good work! 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. ___ 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] FE-5680A DDS Board/PIC Code
On 02/18/2013 10:32 PM, Herbert Poetzl wrote: I'm new to the time-nuts community, so I simply start with a short info on how I got into this situation :) (skip forward toONTOPIC if not interested) Not long ago, I decided to build a reasonably good frequency counter for my personal use and maybe if the result is simple and elegant, I'll publish the details so that everybody can build one ... It was clear to me, that it had to be able to count up to at least 1GHz and thus show at least nine, better ten significant digits, so a precise time base is required. After some online searches and investigations, my best options seemed to get a very stable oscillator and a high quality time reference to sync with, which in turn brought me to the idea to use a cheap rubidium normal and somehow tune/measure/sync it via GPS or DCF-77/MSF-60. Reading a lot of documentation and blogs from all over the world (sometimes in translation :) shed some light on the rubidium normal requirements, which I defined as: - has to have a 10MHz output not just the 1PPS - has to be programmable (i.e. can be tuned) - must be cheap I quickly found two different RB standard models, readily available on ebay for a reasonable price, namely the Efratom FRS-C and the FEI FE-5680A. I finally decided to go with the FE-5680A, mainly because I liked the package. A seller was quickly found offering something titled: 'FE-5680A Rubidium Atomic Frequency Standard Oscillator Transceivers 10Mhz Out' 'Programmable from 1Hz to 20MHz' Little did I know what that actually meant ... When the units (I ordered two of them) arrived, I couldn't wait to test if they actually work and get a lock, so I quickly wired them up (according to the pinout) and provided them with the advised 15V at up to 2A each. To my astonishment, they heated up rather quickly and got a lock in a little under two minutes, so I happily got my scope out to check the 10MHz signal, just to find that there is no such signal available on the 9pin D-sub connector. Measuring pins against ground (pin 2) and 15Vx (pin 1) I figured that neither pin 7 (10MHz) nor pin 8/9 (the rs232 interface for programming) was connected. and to my great disappointment, pin 6 (1PPS) didn't output much either (I later discovered that this was due to a defective unit, which is now being replaced) After contacting the seller, I opened up the units to investigate my options (and of course, because I wanted to take a look inside :), which in turn led to a number of high resolution scans and photos of all the bits and pieces. A (this time) more thorough search on the internet resulted in a deeper understanding of the various options the FE-5680A can have (or usually doesn't have) and the inner workings of the different FE-5680A models (of course, all labeled FE-5680A :) The DDS board, which actually can be programmed to output certain frequencies derived from the 'locked' 1:136 frequency of the rubidium 6.8GHz transition, caught my attention, as it has both, the '10Mhz' output and the programming interface, so I decided to analyze it further ... ONTOPIC The central part on this specific DDS board [1] is the AD9830A a Direct Digital Synthesizer (DDS) which basically produces a sine wave at a well defined multiple and phase of a given reference frequency. Besides some other components, this board also includes an RS-232C line driver (Sipex SP233A) a PIC16F84 microcontroller and two 74HC595 8bit shift registers, with buffered outputs. I read somewhere, that the blue buttons on that DDS board can be used to adjust the output frequency, this should be avoided, mainly because every button press is an update and will cause a write to the EEPROM data wearing it out. Now as I've played with PIC microcontrollers for a long time, I wanted to know what this specific controller is doing and how I could use that for my purposes ... The chip was quickly removed and the program as well as configuration memory retrieved (luckily FEI didn't utilize the code/data protection) and together with high resolution scans and photos, a documented and verified assembler listing [2] reverse engineered. Here are the (IMHO) quite interesting findings: - both FREQx registers can be adjusted - the PHASE0 register can be adjusted - none of the changes is permanent, unless you explicitely save the settings - there are only a few commands, without any plausibility checks and/or protection - and yes, the buttons increment/decrement the FREQx settings and trigger a write to the EEPROM after every update. - the serial interface is done in software - the DDS control words are shifted into the 74HC595, buffered and written ; SCR STATUS ; R=50255057.012932Hz F=2ABB5040 ; OK ; ; F=CR FREQxREG (set divider) ; OK ; ; G=CR PHASE (set phase register) ; OK ; ; R=YYCR
[time-nuts] FE-5680A DDS Board/PIC Code
I'm new to the time-nuts community, so I simply start with a short info on how I got into this situation :) (skip forward to ONTOPIC if not interested) Not long ago, I decided to build a reasonably good frequency counter for my personal use and maybe if the result is simple and elegant, I'll publish the details so that everybody can build one ... It was clear to me, that it had to be able to count up to at least 1GHz and thus show at least nine, better ten significant digits, so a precise time base is required. After some online searches and investigations, my best options seemed to get a very stable oscillator and a high quality time reference to sync with, which in turn brought me to the idea to use a cheap rubidium normal and somehow tune/measure/sync it via GPS or DCF-77/MSF-60. Reading a lot of documentation and blogs from all over the world (sometimes in translation :) shed some light on the rubidium normal requirements, which I defined as: - has to have a 10MHz output not just the 1PPS - has to be programmable (i.e. can be tuned) - must be cheap I quickly found two different RB standard models, readily available on ebay for a reasonable price, namely the Efratom FRS-C and the FEI FE-5680A. I finally decided to go with the FE-5680A, mainly because I liked the package. A seller was quickly found offering something titled: 'FE-5680A Rubidium Atomic Frequency Standard Oscillator Transceivers 10Mhz Out' 'Programmable from 1Hz to 20MHz' Little did I know what that actually meant ... When the units (I ordered two of them) arrived, I couldn't wait to test if they actually work and get a lock, so I quickly wired them up (according to the pinout) and provided them with the advised 15V at up to 2A each. To my astonishment, they heated up rather quickly and got a lock in a little under two minutes, so I happily got my scope out to check the 10MHz signal, just to find that there is no such signal available on the 9pin D-sub connector. Measuring pins against ground (pin 2) and 15Vx (pin 1) I figured that neither pin 7 (10MHz) nor pin 8/9 (the rs232 interface for programming) was connected. and to my great disappointment, pin 6 (1PPS) didn't output much either (I later discovered that this was due to a defective unit, which is now being replaced) After contacting the seller, I opened up the units to investigate my options (and of course, because I wanted to take a look inside :), which in turn led to a number of high resolution scans and photos of all the bits and pieces. A (this time) more thorough search on the internet resulted in a deeper understanding of the various options the FE-5680A can have (or usually doesn't have) and the inner workings of the different FE-5680A models (of course, all labeled FE-5680A :) The DDS board, which actually can be programmed to output certain frequencies derived from the 'locked' 1:136 frequency of the rubidium 6.8GHz transition, caught my attention, as it has both, the '10Mhz' output and the programming interface, so I decided to analyze it further ... ONTOPIC The central part on this specific DDS board [1] is the AD9830A a Direct Digital Synthesizer (DDS) which basically produces a sine wave at a well defined multiple and phase of a given reference frequency. Besides some other components, this board also includes an RS-232C line driver (Sipex SP233A) a PIC16F84 microcontroller and two 74HC595 8bit shift registers, with buffered outputs. I read somewhere, that the blue buttons on that DDS board can be used to adjust the output frequency, this should be avoided, mainly because every button press is an update and will cause a write to the EEPROM data wearing it out. Now as I've played with PIC microcontrollers for a long time, I wanted to know what this specific controller is doing and how I could use that for my purposes ... The chip was quickly removed and the program as well as configuration memory retrieved (luckily FEI didn't utilize the code/data protection) and together with high resolution scans and photos, a documented and verified assembler listing [2] reverse engineered. Here are the (IMHO) quite interesting findings: - both FREQx registers can be adjusted - the PHASE0 register can be adjusted - none of the changes is permanent, unless you explicitely save the settings - there are only a few commands, without any plausibility checks and/or protection - and yes, the buttons increment/decrement the FREQx settings and trigger a write to the EEPROM after every update. - the serial interface is done in software - the DDS control words are shifted into the 74HC595, buffered and written ; SCR STATUS ; R=50255057.012932Hz F=2ABB5040 ; OK ; ; F=CRFREQxREG (set divider) ; OK ; ; G=CRPHASE (set phase register) ; OK ; ; R=YYCR RUBIDIUM (set calibrated freq) ; OK ; ;
Re: [time-nuts] FE-5680A DDS Board/PIC Code
Herbert Thanks for the assembly listing. Someone else on time-nuts had done quite the job of reverse engineering the schematics and other information. Seems like the two of you could collaborate. Sorry do not recall the name. Welcome to time-nuts. Regards Paul WB8TSL On Mon, Feb 18, 2013 at 4:32 PM, Herbert Poetzl herb...@13thfloor.atwrote: I'm new to the time-nuts community, so I simply start with a short info on how I got into this situation :) (skip forward to ONTOPIC if not interested) Not long ago, I decided to build a reasonably good frequency counter for my personal use and maybe if the result is simple and elegant, I'll publish the details so that everybody can build one ... It was clear to me, that it had to be able to count up to at least 1GHz and thus show at least nine, better ten significant digits, so a precise time base is required. After some online searches and investigations, my best options seemed to get a very stable oscillator and a high quality time reference to sync with, which in turn brought me to the idea to use a cheap rubidium normal and somehow tune/measure/sync it via GPS or DCF-77/MSF-60. Reading a lot of documentation and blogs from all over the world (sometimes in translation :) shed some light on the rubidium normal requirements, which I defined as: - has to have a 10MHz output not just the 1PPS - has to be programmable (i.e. can be tuned) - must be cheap I quickly found two different RB standard models, readily available on ebay for a reasonable price, namely the Efratom FRS-C and the FEI FE-5680A. I finally decided to go with the FE-5680A, mainly because I liked the package. A seller was quickly found offering something titled: 'FE-5680A Rubidium Atomic Frequency Standard Oscillator Transceivers 10Mhz Out' 'Programmable from 1Hz to 20MHz' Little did I know what that actually meant ... When the units (I ordered two of them) arrived, I couldn't wait to test if they actually work and get a lock, so I quickly wired them up (according to the pinout) and provided them with the advised 15V at up to 2A each. To my astonishment, they heated up rather quickly and got a lock in a little under two minutes, so I happily got my scope out to check the 10MHz signal, just to find that there is no such signal available on the 9pin D-sub connector. Measuring pins against ground (pin 2) and 15Vx (pin 1) I figured that neither pin 7 (10MHz) nor pin 8/9 (the rs232 interface for programming) was connected. and to my great disappointment, pin 6 (1PPS) didn't output much either (I later discovered that this was due to a defective unit, which is now being replaced) After contacting the seller, I opened up the units to investigate my options (and of course, because I wanted to take a look inside :), which in turn led to a number of high resolution scans and photos of all the bits and pieces. A (this time) more thorough search on the internet resulted in a deeper understanding of the various options the FE-5680A can have (or usually doesn't have) and the inner workings of the different FE-5680A models (of course, all labeled FE-5680A :) The DDS board, which actually can be programmed to output certain frequencies derived from the 'locked' 1:136 frequency of the rubidium 6.8GHz transition, caught my attention, as it has both, the '10Mhz' output and the programming interface, so I decided to analyze it further ... ONTOPIC The central part on this specific DDS board [1] is the AD9830A a Direct Digital Synthesizer (DDS) which basically produces a sine wave at a well defined multiple and phase of a given reference frequency. Besides some other components, this board also includes an RS-232C line driver (Sipex SP233A) a PIC16F84 microcontroller and two 74HC595 8bit shift registers, with buffered outputs. I read somewhere, that the blue buttons on that DDS board can be used to adjust the output frequency, this should be avoided, mainly because every button press is an update and will cause a write to the EEPROM data wearing it out. Now as I've played with PIC microcontrollers for a long time, I wanted to know what this specific controller is doing and how I could use that for my purposes ... The chip was quickly removed and the program as well as configuration memory retrieved (luckily FEI didn't utilize the code/data protection) and together with high resolution scans and photos, a documented and verified assembler listing [2] reverse engineered. Here are the (IMHO) quite interesting findings: - both FREQx registers can be adjusted - the PHASE0 register can be adjusted - none of the changes is permanent, unless you explicitely save the settings - there are only a few commands, without any plausibility checks and/or protection - and yes, the buttons increment/decrement the FREQx settings and trigger a write to the EEPROM after every update. - the serial
Re: [time-nuts] FE-5680A DDS Board/PIC Code
Hi There's quite a bit less in the PIC code than I would have expected. If that's everything that's there, the PIC does very little heavy lifting. Nice job on the dis-assembly. Many of the 10 MHz out FE Rb's are actually the 1 pps version that has been converted to 10 MHz after the fact. The 10 MHz is not very clean on the FE's in any case. Bob On Feb 18, 2013, at 4:32 PM, Herbert Poetzl herb...@13thfloor.at wrote: I'm new to the time-nuts community, so I simply start with a short info on how I got into this situation :) (skip forward to ONTOPIC if not interested) Not long ago, I decided to build a reasonably good frequency counter for my personal use and maybe if the result is simple and elegant, I'll publish the details so that everybody can build one ... It was clear to me, that it had to be able to count up to at least 1GHz and thus show at least nine, better ten significant digits, so a precise time base is required. After some online searches and investigations, my best options seemed to get a very stable oscillator and a high quality time reference to sync with, which in turn brought me to the idea to use a cheap rubidium normal and somehow tune/measure/sync it via GPS or DCF-77/MSF-60. Reading a lot of documentation and blogs from all over the world (sometimes in translation :) shed some light on the rubidium normal requirements, which I defined as: - has to have a 10MHz output not just the 1PPS - has to be programmable (i.e. can be tuned) - must be cheap I quickly found two different RB standard models, readily available on ebay for a reasonable price, namely the Efratom FRS-C and the FEI FE-5680A. I finally decided to go with the FE-5680A, mainly because I liked the package. A seller was quickly found offering something titled: 'FE-5680A Rubidium Atomic Frequency Standard Oscillator Transceivers 10Mhz Out' 'Programmable from 1Hz to 20MHz' Little did I know what that actually meant ... When the units (I ordered two of them) arrived, I couldn't wait to test if they actually work and get a lock, so I quickly wired them up (according to the pinout) and provided them with the advised 15V at up to 2A each. To my astonishment, they heated up rather quickly and got a lock in a little under two minutes, so I happily got my scope out to check the 10MHz signal, just to find that there is no such signal available on the 9pin D-sub connector. Measuring pins against ground (pin 2) and 15Vx (pin 1) I figured that neither pin 7 (10MHz) nor pin 8/9 (the rs232 interface for programming) was connected. and to my great disappointment, pin 6 (1PPS) didn't output much either (I later discovered that this was due to a defective unit, which is now being replaced) After contacting the seller, I opened up the units to investigate my options (and of course, because I wanted to take a look inside :), which in turn led to a number of high resolution scans and photos of all the bits and pieces. A (this time) more thorough search on the internet resulted in a deeper understanding of the various options the FE-5680A can have (or usually doesn't have) and the inner workings of the different FE-5680A models (of course, all labeled FE-5680A :) The DDS board, which actually can be programmed to output certain frequencies derived from the 'locked' 1:136 frequency of the rubidium 6.8GHz transition, caught my attention, as it has both, the '10Mhz' output and the programming interface, so I decided to analyze it further ... ONTOPIC The central part on this specific DDS board [1] is the AD9830A a Direct Digital Synthesizer (DDS) which basically produces a sine wave at a well defined multiple and phase of a given reference frequency. Besides some other components, this board also includes an RS-232C line driver (Sipex SP233A) a PIC16F84 microcontroller and two 74HC595 8bit shift registers, with buffered outputs. I read somewhere, that the blue buttons on that DDS board can be used to adjust the output frequency, this should be avoided, mainly because every button press is an update and will cause a write to the EEPROM data wearing it out. Now as I've played with PIC microcontrollers for a long time, I wanted to know what this specific controller is doing and how I could use that for my purposes ... The chip was quickly removed and the program as well as configuration memory retrieved (luckily FEI didn't utilize the code/data protection) and together with high resolution scans and photos, a documented and verified assembler listing [2] reverse engineered. Here are the (IMHO) quite interesting findings: - both FREQx registers can be adjusted - the PHASE0 register can be adjusted - none of the changes is permanent, unless you explicitely save the settings - there are only a few commands, without any plausibility checks and/or protection - and yes, the buttons
Re: [time-nuts] FE-5680A DDS Board/PIC Code
In a message dated 18/02/2013 22:45:12 GMT Standard Time, paulsw...@gmail.com writes: Herbert Thanks for the assembly listing. Someone else on time-nuts had done quite the job of reverse engineering the schematics and other information. Seems like the two of you could collaborate. Sorry do not recall the name. Welcome to time-nuts. Regards Paul WB8TSL Was just thinking the same thing so checked through my archives. That was Elio, _eliocor@gmail.com_ (mailto:elio...@gmail.com) , messages posted here about a year ago. The messages will be in the list archives anyway but below is the text of two messages I saved. Regards Nigel GM8PZR -- From: elio...@gmail.com Reply-to: time-nuts@febo.com To: time-nuts@febo.com Sent: 15/02/2012 01:31:32 GMT Standard Time Subj: [time-nuts] FE-5680A Schematics (v0.1) at the following address: http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_schematics_v0.1.p df you will find the 0.1 release of the FE-5680A schematics. New additions: - pinout of the unpopulated (24 pin) connector (J9) behind the DB9 - connections between CPU/MAX3232 and the *TWO* serial ports!!! - component values of the 10MHz filter + option on PCB to output a square 10MHz wave on DB9 - connections between CPU and MAX1246 (A/D converter) - connections between XC9572 and MAX392 (quad analog switch) - unknown pins marked as '?' As you can see, it seems FE-5680A fully supports 2 serial ports: one on DB9 and the other one on the unpopulated connector (J9) behind DB9. Any comments/suggestions are welcome. . ciao _Elio. _ From: elio...@gmail.com Reply-to: time-nuts@febo.com To: time-nuts@febo.com Sent: 24/02/2012 01:03:56 GMT Standard Time Subj: [time-nuts] FE-5680A Schematics and scans Thanks to Ignacio (EB4APL) and the generosity of Mike Harrison, today I received a PCB of a disassembled FE5680A. I provided to make some scans of the board at 2400DPI resolution: the picture size is about 7700x11500 pixel (9MB) Top face (with and without ICs): http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_Top001.jpg http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_Top001_noIC.jpg Bottom face (with and without ICs): http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_Bottom001.jpg http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_Bottom001_noIC.jp g Being able to remove the ICs, I was able to correct some flaws in the previous schematics: http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_schematics_v0.2.p df During the next week I will continue to write down the logical part of the circuit and I hope will be able to dump the 8032 firmware _ Elio. _ ___ 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] FE-5680A DDS Board/PIC Code
Hi Herbert, Nice work ! A few comments that may help you in your quest. There are two primary methodologies used in the FEI-5680A Rubidium. It appears, from your picture, what you have is the older style that is analog for control of the Rubidium frequency control loop. A VERY GOOD THING ! Why, because the analog C field pot is active in such a unit, permitting adjustment allowing you to put it right on the mark. This easily allows you to extend, externally, the C field control and be able to put it in an external loop with a GPS without much trouble. In the first methodology, the original designed was, totally, an analog control. The micro controller is used to talk to only the DDS which is outside of the Rubidium control loop. The Rubidium control loop starts with a 50.+ MHz oscillator frequency multiplied up to the Rubidium and the feedback from the photo multiplier is fed back to control the 50.+ MHz oscillator. This 50.+ MHz is the reference frequency for the DDS on the board in your picture. The second methodology is a bit more complicated because FEI switched to digital control of the Rubidium frequency loop. Here, an internal 60. MHz oscillator is used as a base signal. A DDS, whose reference is from the same 60 MHz oscillator generates the required offset and mixed with the 60 MHz to produced the final multiplied signal to the Rubidium filter. The photo multiplier is sensed and eventually runs a DAC to control the 60 MHz oscillator. The problem with this approach, due to the computerization and digital stepping, is you can get close but not necessarily right spot on for frequency. Depending upon your house standards, that may or may not be an issue. To put it in perspective, I think the adjustment process in the newer methodology is either parts in the 10E-12 or -13. The output frequencies that the customer sees are derived via circuitry outside the loop like the old method except they have switched to using either an ASIC or FPGA of some sort making it quite difficult to determine what is going on. Equally so is the fact that the ASIC/FPGA's are controlled by software. Of course, FEI is not going to be forthcoming on the internals, nor do they want to tell how to use their computer link to control the Rubidium unless you are a customer. As a hobbyist, you are left with a much harder unit to integrate into external control mechanisms. Even though the C field pot is still there it is not active in the unit. Someone or more have been investigating methods to find a proper point with which to inject an outside DC signal to attempt a C field like control. I do not know what their success has been. FEI's part number system is really two different processes. The FEI-5680A number is the generic case and layout style, etc. and another order number is attached that tells what is actually arranged inside. So, the upshot is the older arrangement is easier to play with. Hope this has been helpful, BillWB6BNQ Herbert Poetzl wrote: I'm new to the time-nuts community, so I simply start with a short info on how I got into this situation :) (skip forward to ONTOPIC if not interested) Not long ago, I decided to build a reasonably good frequency counter for my personal use and maybe if the result is simple and elegant, I'll publish the details so that everybody can build one ... It was clear to me, that it had to be able to count up to at least 1GHz and thus show at least nine, better ten significant digits, so a precise time base is required. After some online searches and investigations, my best options seemed to get a very stable oscillator and a high quality time reference to sync with, which in turn brought me to the idea to use a cheap rubidium normal and somehow tune/measure/sync it via GPS or DCF-77/MSF-60. Reading a lot of documentation and blogs from all over the world (sometimes in translation :) shed some light on the rubidium normal requirements, which I defined as: - has to have a 10MHz output not just the 1PPS - has to be programmable (i.e. can be tuned) - must be cheap I quickly found two different RB standard models, readily available on ebay for a reasonable price, namely the Efratom FRS-C and the FEI FE-5680A. I finally decided to go with the FE-5680A, mainly because I liked the package. A seller was quickly found offering something titled: 'FE-5680A Rubidium Atomic Frequency Standard Oscillator Transceivers 10Mhz Out' 'Programmable from 1Hz to 20MHz' Little did I know what that actually meant ... When the units (I ordered two of them) arrived, I couldn't wait to test if they actually work and get a lock, so I quickly wired them up (according to the pinout) and provided them with the advised 15V at up to 2A each. To my astonishment, they heated up rather quickly and got a lock in a little under two minutes, so I happily got my scope out to check the 10MHz signal, just to find that there is no such
Re: [time-nuts] FE-5680A DDS Board/PIC Code
Hi, Probably Elio will jump in and tell us more on this, but I must advice that the unit where he did his forensic examination was a FE-5680A of the 10 MHz fixed frequency output variety (not accounting for the small adjustment margin)and also has a fixed 1 PPS. This unit doesn't have the two blue buttons and is essentially different from the programmable units. Its DDS is used in a very different way and the PIC program should be totally different. Regards, Ignacio, EB4APL On 18/02/2013 23:54, gandal...@aol.com wrote: In a message dated 18/02/2013 22:45:12 GMT Standard Time, paulsw...@gmail.com writes: Herbert Thanks for the assembly listing. Someone else on time-nuts had done quite the job of reverse engineering the schematics and other information. Seems like the two of you could collaborate. Sorry do not recall the name. Welcome to time-nuts. Regards Paul WB8TSL Was just thinking the same thing so checked through my archives. That was Elio, _eliocor@gmail.com_ (mailto:elio...@gmail.com) , messages posted here about a year ago. The messages will be in the list archives anyway but below is the text of two messages I saved. Regards Nigel GM8PZR -- From: elio...@gmail.com Reply-to: time-nuts@febo.com To: time-nuts@febo.com Sent: 15/02/2012 01:31:32 GMT Standard Time Subj: [time-nuts] FE-5680A Schematics (v0.1) at the following address: http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_schematics_v0.1.p df you will find the 0.1 release of the FE-5680A schematics. New additions: - pinout of the unpopulated (24 pin) connector (J9) behind the DB9 - connections between CPU/MAX3232 and the *TWO* serial ports!!! - component values of the 10MHz filter + option on PCB to output a square 10MHz wave on DB9 - connections between CPU and MAX1246 (A/D converter) - connections between XC9572 and MAX392 (quad analog switch) - unknown pins marked as '?' As you can see, it seems FE-5680A fully supports 2 serial ports: one on DB9 and the other one on the unpopulated connector (J9) behind DB9. Any comments/suggestions are welcome. . ciao _Elio. _ From: elio...@gmail.com Reply-to: time-nuts@febo.com To: time-nuts@febo.com Sent: 24/02/2012 01:03:56 GMT Standard Time Subj: [time-nuts] FE-5680A Schematics and scans Thanks to Ignacio (EB4APL) and the generosity of Mike Harrison, today I received a PCB of a disassembled FE5680A. I provided to make some scans of the board at 2400DPI resolution: the picture size is about 7700x11500 pixel (9MB) Top face (with and without ICs): http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_Top001.jpg http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_Top001_noIC.jpg Bottom face (with and without ICs): http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_Bottom001.jpg http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_Bottom001_noIC.jp g Being able to remove the ICs, I was able to correct some flaws in the previous schematics: http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_schematics_v0.2.p df During the next week I will continue to write down the logical part of the circuit and I hope will be able to dump the 8032 firmware _ Elio. _ ___ 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.
