saadc scan output order sdk 12.2.0

RE: saadc scan output order sdk 12.2.0

Jørgen Holmefjord — Tue, 15 May 2018 06:35:18 GMT

If you see a channel shift after calibration, this is most likely caused by errata 86. Please try to implement the suggested workaround.

RE: saadc scan output order sdk 12.2.0

dmf3030 — Mon, 14 May 2018 15:27:12 GMT

Looks like I may have solved this by doing a buffer convert on the buffer when it comes in on the EVT_DONE after calibration but before the EVT_CALIBRATEDONE comes in. I don't think the git example does this buffer convert, which is what threw me off.

RE: saadc scan output order sdk 12.2.0

dmf3030 — Mon, 14 May 2018 15:10:39 GMT

Any update on this, I'm seeing my channels shift position after my first calibration call, which happens roughly every 500 samples. After the first calibration call the channels seem to hold their new positions through any following calibration calls, so not sure if there is something special that happens on an initial calibration that doesn't happen later?

RE: saadc scan output order sdk 12.2.0

Jørgen Holmefjord — Wed, 12 Apr 2017 12:20:15 GMT

Hi,

The main issue in your code seems to be that you are setting up the buffer for conversion again before reading the values, by calling:

nrf_drv_saadc_buffer_convert(m_buffer_pool[0],SAADC_SAMPLES_IN_BUFFER);

Almost at the top of the SAADC callback handler. You should move this call to the end of the handler, to avoid that the buffer is overwritten by the sample task before you read the values in the buffer.

After placing this call after reading the buffer, I only see issues on the samples received after calibration (NRF_DRV_SAADC_EVT_DONE is called 4096 times between each time the buffer contains wrong values). I will do some more research on why this buffer is not correct.

Best regards,

Jørgen

RE: saadc scan output order sdk 12.2.0

Ryjan — Mon, 10 Apr 2017 19:51:41 GMT

It is uploaded to MyCase.

RE: saadc scan output order sdk 12.2.0

Jørgen Holmefjord — Mon, 10 Apr 2017 07:46:36 GMT

The whole project would be preferable, to check if there is some other components affecting the behavior. I'm not aware of any such directions, but it should be quite easy when you have created an account and follow this page. Some information can also be found in this article.

RE: saadc scan output order sdk 12.2.0

Ryjan — Fri, 07 Apr 2017 15:20:57 GMT

Do you want the whole firmware project or will the ADC stuff suffice? Is there a place with directions on how MyPage is used?

RE: saadc scan output order sdk 12.2.0

Jørgen Holmefjord — Fri, 07 Apr 2017 14:46:16 GMT

I'm looking into a similar case here. It would be usefull if you could share your firmware code, so we can see if we can find some common settings in these cases that cause this behaviour.

RE: saadc scan output order sdk 12.2.0

Ryjan — Fri, 07 Apr 2017 14:36:49 GMT

I'm using BLE and the S132 stack. I can try hacking out the BLE sections. The final product will need BLE in the end.

RE: saadc scan output order sdk 12.2.0

Jørgen Holmefjord — Fri, 07 Apr 2017 07:18:58 GMT

Are you using BLE in your application? If you do, do you still get unpredictable output if you disable BLE?