I was experimenting with the same setup for STM32 MCU. This microprocessor has accept the sine wave from external OCXO or GPSDO. No problem with this. The only thing: I was need to start MCU from slow "watch" crystal first. And then switch it to work to external one. In another case I got incorrect timing settings for MCU. Later, I decide to implement LTC6957-3 chip to "share" REFCLOCK source, since that chip has two equal CMOS-level outputs. Unfortunately I have no tool to measure the phase noise and jitters on each setup. > It turns out all of this is built into the AVR chip. There is a > counter > and logic to copy the current counter value to a register on a PPS > pulse > raising edge. The counter keeps running and every second its value > is > trapped. > > I can connect the OCXO and the PPS directly to the AVR pin. The AVR > has > hardware (a fast comparator) to "square" a low amplitude sine wave and > trap > the counter on a zero crossing. So it looks like I can get rid of > ALL of > the external chips. The built in DAC is working well also but it > needs > some external resisters and caps. > > No need for '74 FFs or '373' or counter chips. I do get precision > timing > with no time critical software, no 74xxx chips. -- WBW, V.P.

Good afternoon very interested in the work you are doing with the STM board. As I mentioned far earlier in this thread I am attempting to use it to correct the BPSK WWVB signal here. Initial thoughts were using FORTH to program the STM board. Very curious what you are using as examples. My experience in FORTH is from many years ago and have done very poorly at C. But this may be the case to have something of interest to actually do. In either language. Regards Paul WB8TSL On Mon, Apr 14, 2014 at 12:27 PM, d0ct0r <time@patoka.org> wrote: > > > I was experimenting with the same setup for STM32 MCU. This microprocessor > has accept the sine wave from external OCXO or GPSDO. No problem with this. > The only thing: I was need to start MCU from slow "watch" crystal first. > And then switch it to work to external one. In another case I got incorrect > timing settings for MCU. Later, I decide to implement LTC6957-3 chip to > "share" REFCLOCK source, since that chip has two equal CMOS-level outputs. > Unfortunately I have no tool to measure the phase noise and jitters on > each setup. > > > > > It turns out all of this is built into the AVR chip. There is a counter >> and logic to copy the current counter value to a register on a PPS pulse >> raising edge. The counter keeps running and every second its value is >> trapped. >> >> I can connect the OCXO and the PPS directly to the AVR pin. The AVR has >> hardware (a fast comparator) to "square" a low amplitude sine wave and >> trap >> the counter on a zero crossing. So it looks like I can get rid of ALL >> of >> the external chips. The built in DAC is working well also but it needs >> some external resisters and caps. >> >> No need for '74 FFs or '373' or counter chips. I do get precision >> timing >> with no time critical software, no 74xxx chips. >> > -- > 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. >

Perhaps this thread should go off line not to distract from the originators thread. Regards Paul. On Mon, Apr 21, 2014 at 4:29 PM, paul swed <paulswedb@gmail.com> wrote: > Good afternoon very interested in the work you are doing with the STM > board. > As I mentioned far earlier in this thread I am attempting to use it to > correct the BPSK WWVB signal here. Initial thoughts were using FORTH to > program the STM board. > Very curious what you are using as examples. > My experience in FORTH is from many years ago and have done very poorly at > C. But this may be the case to have something of interest to actually do. > In either language. > Regards > Paul > WB8TSL > > > On Mon, Apr 14, 2014 at 12:27 PM, d0ct0r <time@patoka.org> wrote: > >> >> >> I was experimenting with the same setup for STM32 MCU. This >> microprocessor has accept the sine wave from external OCXO or GPSDO. No >> problem with this. The only thing: I was need to start MCU from slow >> "watch" crystal first. And then switch it to work to external one. In >> another case I got incorrect timing settings for MCU. Later, I decide to >> implement LTC6957-3 chip to "share" REFCLOCK source, since that chip has >> two equal CMOS-level outputs. >> Unfortunately I have no tool to measure the phase noise and jitters on >> each setup. >> >> >> >> >> It turns out all of this is built into the AVR chip. There is a counter >>> and logic to copy the current counter value to a register on a PPS pulse >>> raising edge. The counter keeps running and every second its value is >>> trapped. >>> >>> I can connect the OCXO and the PPS directly to the AVR pin. The AVR has >>> hardware (a fast comparator) to "square" a low amplitude sine wave and >>> trap >>> the counter on a zero crossing. So it looks like I can get rid of ALL >>> of >>> the external chips. The built in DAC is working well also but it needs >>> some external resisters and caps. >>> >>> No need for '74 FFs or '373' or counter chips. I do get precision >>> timing >>> with no time critical software, no 74xxx chips. >>> >> -- >> 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. >> > >

               +--- STM32 -- (Pulse Counter, TTL Generator, DDS 

Actually GCC supporting Cortex. So, I am using Raisonance IDE plus GCC Toolchain as a development environment. My current project functional diagram is following: +--- STM32 -- (Pulse Counter, TTL Generator, DDS driver, GPSDO monitor) GPSDO--LTC6957-3--| | | | +--- AD9852 -- VFO -> | | v +------------------------------------------- TADD3 -- (1PPS, TTL) --> As I'll finish it more or less, I'd like to compare the 1PPS which comes directly from GPSDO with 1PPS which I could create on MCU (and probably on DDS). As I mention before, each STM MCU comes with very useful Peripheral Library. That Library has tonnes of different examples. Regards, V.P. On 2014-04-21 16:29, paul swed wrote: > Good afternoon very interested in the work you are doing with the STM > board. > As I mentioned far earlier in this thread I am attempting to use it to > correct the BPSK WWVB signal here. Initial thoughts were using FORTH > to program the STM board. > Very curious what you are using as examples. > My experience in FORTH is from many years ago and have done very > poorly at C. But this may be the case to have something of interest to > actually do. In either language. > Regards > Paul > WB8TSL > > On Mon, Apr 14, 2014 at 12:27 PM, d0ct0r <time@patoka.org> wrote: > >> I was experimenting with the same setup for STM32 MCU. This >> microprocessor has accept the sine wave from external OCXO or GPSDO. >> No problem with this. The only thing: I was need to start MCU from >> slow "watch" crystal first. And then switch it to work to external >> one. In another case I got incorrect timing settings for MCU. Later, >> I decide to implement LTC6957-3 chip to "share" REFCLOCK source, >> since that chip has two equal CMOS-level outputs. >> Unfortunately I have no tool to measure the phase noise and jitters >> on each setup. >> >>> It turns out all of this is built into the AVR chip.   There is a >>> counter >>> and logic to copy the current counter value to a register on a >>> PPS pulse >>> raising edge.    The counter keeps running and every second its >>> value is >>> trapped. >>> >>> I can connect the OCXO and the PPS directly to the AVR pin.  The >>> AVR has >>> hardware (a fast comparator) to "square" a low amplitude sine >>> wave and trap >>> the counter on a zero crossing.   So it looks like I can get rid >>> of  ALL of >>> the external chips.   The built in DAC is working well also but >>> it needs >>> some external resisters and caps. >>> >>> No need for '74 FFs or '373' or counter chips.    I do get >>> precision timing >>> with no time critical software, no 74xxx chips. >> -- >> 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 [1] >> and follow the instructions there. > > > > Links: > ------ > [1] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts -- WBW, V.P.

Hi! If it is all the same for you, I prefer this thread continue "in the open" as I am interested both in using an Arduino-like for my first GPSDO and STM32 for event capture and timming. Regards, Edésio On Mon, Apr 21, 2014 at 04:29:35PM -0400, paul swed wrote: > Good afternoon very interested in the work you are doing with the STM board. > As I mentioned far earlier in this thread I am attempting to use it to > correct the BPSK WWVB signal here. Initial thoughts were using FORTH to > program the STM board. > Very curious what you are using as examples. > My experience in FORTH is from many years ago and have done very poorly at > C. But this may be the case to have something of interest to actually do. > In either language. > Regards > Paul > WB8TSL > > > On Mon, Apr 14, 2014 at 12:27 PM, d0ct0r <time@patoka.org> wrote: > > > > > > > I was experimenting with the same setup for STM32 MCU. This microprocessor > > has accept the sine wave from external OCXO or GPSDO. No problem with this. > > The only thing: I was need to start MCU from slow "watch" crystal first. > > And then switch it to work to external one. In another case I got incorrect > > timing settings for MCU. Later, I decide to implement LTC6957-3 chip to > > "share" REFCLOCK source, since that chip has two equal CMOS-level outputs. > > Unfortunately I have no tool to measure the phase noise and jitters on > > each setup. > > > > > > > > > > It turns out all of this is built into the AVR chip. There is a counter > >> and logic to copy the current counter value to a register on a PPS pulse > >> raising edge. The counter keeps running and every second its value is > >> trapped. > >> > >> I can connect the OCXO and the PPS directly to the AVR pin. The AVR has > >> hardware (a fast comparator) to "square" a low amplitude sine wave and > >> trap > >> the counter on a zero crossing. So it looks like I can get rid of ALL > >> of > >> the external chips. The built in DAC is working well also but it needs > >> some external resisters and caps. > >> > >> No need for '74 FFs or '373' or counter chips. I do get precision > >> timing > >> with no time critical software, no 74xxx chips. > >> > > -- > > 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. > > > _______________________________________________ > 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.