A little follow up. After more tests, it became clear that temperature change, including board self heating, was problematic for the desired long term stability. Tests were done to try and control temperature drift, but the dynamics appeared too difficult toward achieving stable operation within a few tenths of a degree. So, I ran tests to determine a timing correction coefficient versus temperature. It was found to be a simple linear relationship and an equation easily applied. A thermocouple input module will be added (when it arrives) such that the Teensy board can report on its own (xtal area) temperature. The host computer can then acquire the data and make the appropriate corrections. This has been tested manually with good results.
Defragster, thanks for the tip on com ports greater than 9. The Windows thing was that nearly all com ports were busy - even though only two +Teensy USB ports were in use. I still need to sort that out. BenS
Defragster, thanks for the tip on com ports greater than 9. The Windows thing was that nearly all com ports were busy - even though only two +Teensy USB ports were in use. I still need to sort that out. BenS