nRF9160 > Count pulse on GPIO

[Oleh]

Dear Team,

what is the way to do it in Zephyr? 

I have a signal up-to 10kHz, what is the best way to keep the counter in the background?

Thank you and best

Oleh

[Didrik Rokhaug]

Hi.

You can use Zephyr's GPIO driver to configure interrupts. 

Have a look at the documentation here.

Best regards,

Didrik

[Oleh]

Hi Didrik,

thank you, I'm new to Zephyr so trying to map my nrf knowledge to zephyr

To complement and test the counter on gpio, I thought to put the second DevKit board into generation mode. Could you please point on the right track with how can the generation on-off be done in background on Zephyr?

thanks & best

Oleh

[Oleh]

thank you, now I am trying to make it working on the latest ncs git... but getting errors...

 is there anything I have to change?

***** Booting Zephyr OS build v1.14.99-ncs3-snapshot2-2647-gd6e67554cfeb *****
starting application...
starting init gpiote...
prepare time 1 cfg...
uninit time 1...
init time 1...
prepare time 2 cfg...
uninit time 2...
init time 2...
nrfx_timer_ms_to_ticks...
nrfx_timer_extended_compare...
gpiote_setup...
gpiote_setup...
gpiote_evt_addr: 0x5000d100
NRF_GPIOTE_EVENTS_IN_0: 0x00000100
NRF_GPIOTE1_NS: 0x40031000
gpiote_evt_addr - NRF_GPIOTE0_S: 0x0ffdc100
[00:00:00.069,274] <err> os: ***** BUS FAULT *****
[00:00:00.069,274] <err> os:   Precise data bus error
[00:00:00.069,274] <err> os:   BFAR Address: 0x40010088
[00:00:00.069,305] <err> os: r0/a1:  0x00000000  r1/a2:  0x00000001  r2/a3:  0x80000000
[00:00:00.069,305] <err> os: r3/a4:  0x40010088 r12/ip:  0x00000030 r14/lr:  0x0000061f
[00:00:00.069,305] <err> os:  xpsr:  0x29000000
[00:00:00.069,305] <err> os: Faulting instruction address (r15/pc): 0x00000632
[00:00:00.069,335] <err> os: >>> ZEPHYR FATAL ERROR 0: CPU exception
[00:00:00.069,335] <err> os: Current thread: 0x20000274 (unknown)
[00:00:00.140,075] <err> os: Halting system

[Didrik Rokhaug]

Hi.

A pull request for a sample demonstrating how to use the nrfx drivers in Zephyr was just opened.

Hopefully, it is able to help you.

https://github.com/zephyrproject-rtos/zephyr/pull/20089/files

Best regards,

Didrik

[Oleh]

Hello and thank you!

short question: what is the best way to suspend / resume the ppi in this sample? 

and how to safely reset counters?

[Didrik Rokhaug]

Hi, and sorry for the late reply.

For resetting counters, I would use the nrfx_timer_clear function.

For suspending/resuming DPPI, you would have to either stop the events from being generated, not publish the events, or subscribe to them (or all at once).

[Oleh]

Hi and thank you for your input.

I managed to update and make the code working! great! thank you!

Regarding the Suspend/Resume, just for info: I need it in order to save power, as the sensor is external and connected to a stepup convertor, so when not in use -- I would like to power it off. Thus also disable DPPI. 

Best regards

Oleh

[Didrik Rokhaug]

After digging some more through the nrfx drivers, I also found the nrfx_dppi_channel_disable (and _enable) functions, which should let you stop and start the specific DPPI channel.

[Oleh]

Hi Didrik, 

you just rock! thank you for all your support!

Best

Oleh