Timer is not stable(phase/duty change all the time).

RE: Timer is not stable(phase/duty change all the time).

FormerMember — Thu, 04 May 2017 08:10:17 GMT

The reason for the seemingly inaccurate timer is because "software" interrupts/interrupt handler can be somewhat inaccurate because the softdevice has higher priority. To get accurate pin toggling, use ppi and gpiote instead. I have attached a modified version of your main.c that uses ppi and gpiote to toggle a pin accurately: main.c

RE: Timer is not stable(phase/duty change all the time).

Stanley — Wed, 03 May 2017 09:26:12 GMT

The following web link is the SDK v12.2.0 tested on nRF52(pca10040) for your reference. By the way, Have you even an example for a counter to count a duty of pulse?

app.box.com/.../ahlxo4f8vwhnjovbzmr3m7zo2d7v2vd3

RE: Timer is not stable(phase/duty change all the time).

FormerMember — Thu, 20 Apr 2017 11:56:56 GMT

It was Easter vacation here last week, so I didn't get a chance to look at your code. Would you mind uploading it again?

RE: Timer is not stable(phase/duty change all the time).

Stanley — Mon, 17 Apr 2017 07:55:30 GMT

Hi Kristin, Have any advices?

RE: Timer is not stable(phase/duty change all the time).

Stanley — Sun, 09 Apr 2017 14:41:09 GMT

I changed the timer number from 0 to 1. It seems more stable, but some issues came with. The major issue is that the frequency I toggled on P0.07 should be around 50KHz. But it was just around 28KHz. I uploaded another file for your reference. By the way, It would be unstable if I the parameter of time_us to 10.

app.box.com/.../dkilsil96szkuage6e6i8pega7b39huh

RE: Timer is not stable(phase/duty change all the time).

Stanley — Sat, 08 Apr 2017 17:00:04 GMT

The following web link is the reference file of my tested at my box cloud. Would you download it and check for us? app.box.com/.../v3vti1ox4h6s55pvn72k5c70nlge58hr

RE: Timer is not stable(phase/duty change all the time).

Stanley — Sat, 08 Apr 2017 16:52:44 GMT

I have tried on the nRF52 EVB(pca10040) to check this issue. It also came out. I will upload the file(main.c) for your reference.

RE: Timer is not stable(phase/duty change all the time).

FormerMember — Fri, 07 Apr 2017 11:51:02 GMT

You can create a new support case on myPage from www.nordicsemi.com, upload the file there and refer to this thread.

RE: Timer is not stable(phase/duty change all the time).

Stanley — Fri, 07 Apr 2017 11:28:04 GMT

I separate the original main.c to several c files. I can send it to you for reference. Where should I send to?

RE: Timer is not stable(phase/duty change all the time).

FormerMember — Thu, 06 Apr 2017 12:15:45 GMT

I would only need the relevant part of main.c, so I can test it here.

RE: Timer is not stable(phase/duty change all the time).

Stanley — Wed, 05 Apr 2017 12:57:10 GMT

Hello Kristin, Thanks for your reply. Should I open the complete C code to you? Please let me know if any questions. I have doubt as you mentioned. But also as I mentioned, it will get stable when I changed the priority of Timer to 1.(// Priorities 0,2 (nRF51) and 0,1,4,5 (nRF52) are reserved for SoftDevice) The value from nrf_drv_timer_us_to_ticks() is 0x140. I think it could the reason of the other timers againsting the timer1 when I set it as priority 3.

RE: Timer is not stable(phase/duty change all the time).

FormerMember — Wed, 05 Apr 2017 10:34:49 GMT

Could you share more of your code so that it is easier to get an overview?

It is most likely not related, but what is the value returned by nrf_drv_timer_us_to_ticks()? From what I can see, the arguments should be the time in microseconds and the frequency of the timer..