stop and restart SAADC to power saving

RE: stop and restart SAADC to power saving

mdido — Thu, 15 Nov 2018 12:48:31 GMT

Hello,

you're right. The semaphore was not volatile. Thank you for the quick support.

Best regards

RE: stop and restart SAADC to power saving

Einar Thorsrud — Thu, 15 Nov 2018 11:22:21 GMT

Hi,

This sounds like a typical thing you could see if the semaphore is not volatile. Is it?

RE: stop and restart SAADC to power saving

mdido — Thu, 15 Nov 2018 10:03:17 GMT

Hello, I used a semaphore in saadc_callback and I wait until is cleared before of saadc_unint. If Optimization level is setted "none" everything works fine, but if I set Optimization level as "Optimize for size" seems that micro does not exit from the saadc callback. Do you have any suggest?

Best regards

RE: stop and restart SAADC to power saving

mdido — Thu, 11 Oct 2018 11:35:53 GMT

Ok, that's all clear.

Thank you for the support

Best regards

RE: stop and restart SAADC to power saving

Einar Thorsrud — Thu, 11 Oct 2018 10:55:28 GMT

Hi,

You are right that if you don't wait for the sampling to finish before disabling you will never get any samples (in the code snippet in my previous answer you can see this by commenting out 78). This is because you uninitialize the driver before sampling has finished, so you never actually get the callback with the sample.

If this is what you are seeing, then I would say you have a bug in your code, as you uninitialize the driver before you are done using it (have not yet received the sample).

RE: stop and restart SAADC to power saving

mdido — Tue, 09 Oct 2018 15:11:38 GMT

Hello,

thank you for the example. Yes, your example differs from my code. I see you used a semaphore in saadc_callback and you wait until is cleared before of saadc_unint. With this change my code works fine.If you do not use the semaphore in your code, do you get the same brhaviour as my previous code?

Best regards

RE: stop and restart SAADC to power saving

Einar Thorsrud — Tue, 09 Oct 2018 13:34:55 GMT

Hi,

That's odd. It should be straight forward, as demonstrated by this example application (adapted and simplified from the SAADC example in SDK 15.0.0):

devzone.nordicsemi.com/.../main.c

Can you compare with the example and see in what way it differs from your implementation?

RE: stop and restart SAADC to power saving

mdido — Tue, 09 Oct 2018 11:47:06 GMT

Hello,the sequence of the operation is:

connection

saadc_init

nrf_drv_saadc_sample

saadc interrupt handler is triggered

disconnection

nrf_drv_saadc_uninit

connection

saadc_init

nrf_drv_saadc_sample

but at this point the saadc interrupt handler is not triggerd; SDK returns no error

Best regards

RE: stop and restart SAADC to power saving

Einar Thorsrud — Tue, 09 Oct 2018 10:45:15 GMT

Hi,

It is fine to call nrf_drv_saadc_uninit() as you do, but then you also have to initialize everything again before the next use. iI is not clear to me whether you do that or not? If not, you should get an assert from the driver if you have built the application with the DEBUG_NRF preprocessor define set (used by default in the Debug target for SES projects in the SDK).

If this is not the problem, can you explain in more detail what you do and how the "interrupt handler of SAADC no longer works"?