Some results... I have pulses coming out of seven different pins. The fastest is 100KHz (that is a 10 uS period). All of them seem to have periods that stay within 0.05 uS of the desired period. That is 50 nS of jitter. I'm measuring with my digital 'scope so I don't 100% trust the measurement. Will use logic analyzer a few days. This is a proof of concept, no interface to higher level control yet and these output pins are only 3.3 volts But it looks like Accurate timing in a non-issue. I need to add a high level interface. Likely just plain old serial so it can connect to a PC but SPI or I2C as well so that it is easier to connect to a Pi3. I will add a queue with flow control to totally remove any need to realtime software in the PC/Pi3
How to generate pulses with 50nS jitter? Use hardware, not software. The uP has 10 hardware counter/compare timers built in and you can program them to divide down the a 1MHz clock. The timing pluses are routed to hardware pins directly and not seen by software. These ARM M4 chips were designed for real time control of things like motors. The lowest priced one that has 10 timers is the STM32F446RE But it is otherwise total gross overkill for this purpose. Cost so far is about $13. -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
