Counter Configuration in Zephyr

[moose]

Hello, how can we configure the counter in an nrfx52840 dev board to count pulses on an input pin in zephyr? There is a counter driver in zephyr, but there doesn't seem to be a way to configure it to count outside transitions. We know the nrf52 hardware can do it. Any inputs? Thx! 

[Håkon Alseth]

Hi,

 

In order to count pulses, you need to place the TIMER instance in COUNTER mode.

If you search for "timer counter mode" on the forum, you can find several examples on how to setup a timer instance in this mode.

 

If you want to count and time the pulse, you should consider to use one TIMER in COUNTER mode, one TIMER in normal capture/compare, GPIOTE IN channels, and PPI.

This setup will only require cpu interaction for setup and the "end interrupt". Please see this implementation for nRF9160 (uses DPPI, so needs a bit of porting) for such a scenario:

https://github.com/Rallare/fw-nrfconnect-nrf/blob/nrf9160_samples/samples/nrf9160/nrfx_timed_signal/src/main.c

 

You can also search on the forum for how to setup this bare-metal/using nrfx drivers directly.

 

Kind regards,

Håkon