Jeremy- Well done! I am certainly interested in learning more about your project. Are your charts available online, or would you mind sending me a copy (dwayne.esterline@krytronx.com) I am running an experiment using a 20mhz OCXO driving 32bit binary counter IC's (sn74lv8154 @ about $1), and sampling the count via Arduino Nano33IOT using an i2C bus, and writing the result to an online mySQL database via wifi. This gives 50ns resolution, but a relatively low sample rate due to the read time of the i2C bus. I can zero the counters and sample the counters very precisely with interrupts, but reading is a multi-byte data transfer process (on the order of 10's of milliseconds). My personal interest is in studying the fine structure of the short term variations and random behaviors of time measurement (what normal time-nuts call noise :-) Looking forward to watching your project develop, and have been learning much from the veterans of this mailing list- keep it coming. -Dwayne Esterline

Sorry, I forgot that time-nuts just sends text/plain and strips HTML and attachments -- I've uploaded my sample datasets to here: https://github.com/jelson/rulos/tree/master/src/app/timestamper/sample-data Your project sounds interesting and along similar lines to mine. I'm excited about the STM32 because it has such great hardware support. I haven't even tried to optimize sampling rate yet, but even the unoptimized code can easy sample once per microsecond. Honestly the limit at this point is probably how quickly I can write data out the serial port. In the next revision I hope to put a native USB interface on the timestamper so it can send data at full USB rates back to the host. Best, -Jeremy On Tue, Feb 16, 2021 at 9:32 AM Dwayne Esterline < Dwayne.Esterline@krytronx.com> wrote: > Jeremy- > > Well done! I am certainly interested in learning more about your project. > Are your charts available online, or would you mind sending me a copy ( > dwayne.esterline@krytronx.com) > > I am running an experiment using a 20mhz OCXO driving 32bit binary counter > IC's (sn74lv8154 @ about $1), and sampling the count via Arduino Nano33IOT > using an i2C bus, and writing the result to an online mySQL database via > wifi. This gives 50ns resolution, but a relatively low sample rate due to > the read time of the i2C bus. I can zero the counters and sample the > counters very precisely with interrupts, but reading is a multi-byte data > transfer process (on the order of 10's of milliseconds). > > My personal interest is in studying the fine structure of the short term > variations and random behaviors of time measurement (what normal time-nuts > call noise :-) > > Looking forward to watching your project develop, and have been learning > much from the veterans of this mailing list- keep it coming. > > -Dwayne Esterline > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. >