RE: Parallel time-stamps of GPIO edges with PPI? (timer capture)

Cedric Honnet — Thu, 30 Nov 2017 15:04:31 GMT

Great! Little note: that's probably a kind of typo but the "Counter register is incremented by one each time the COUNT task is triggered": infocenter.nordicsemi.com/index.jsp So the most appropriate to time-stamp the GPIO edges is probably the timer mode ;) Thanks a lot for your answer!!

PS: In our case we need to time-stamp 4 rising edges + 4 falling edges, so the trick is to use 2 timers as there are not enough otherwise ;)

RE: Parallel time-stamps of GPIO edges with PPI? (timer capture)

Alexis — Wed, 23 Aug 2017 00:55:26 GMT

You can easily do that :

Configure your GPIO to generate events on each rising (or falling or toggle) edge through register CONFIG[n]. You can have up to 8 pins generating events on nRF52840.
Configure the timer in counter mode and start it.
Through PPI connect each pin event to a capture channel task of your timer. You have 6 capture register on nRF52840.

Then every time a pin receive the correct edge, the capture register connected to it will latch the current timer value. All this events can happen at the same time or not, it doesn't matter.

Good luck :)