RE: Sync between PWM and SAADC

mrono — Thu, 20 Aug 2020 10:40:17 GMT

I've never tried it, but there is a PWM event called PWMPERIODEND. It seems like this could be used to trigger sampling on each period like in the illustration.

RE: Sync between PWM and SAADC

Einar Thorsrud — Thu, 20 Aug 2020 10:27:50 GMT

Hi,

There are a few different options:

Connect a GPIO input pin to the PWM output pin, and use PPI to trigger SAADC sampling when there is a transition in the PWM signal. This would give you a predictable delay of a few 16 MHz clock cycles which may or may not be a problem. I suspect this is the best option.
Use the EGU and PPI to trigger the start task for both SAADC and PWM. This would start them at the exact same time, but I suspect this is not what you want in this case (by looking at the image).