Unable to disable SAADC on NRF52832

RE: Unable to disable SAADC on NRF52832

Jørgen Holmefjord — Thu, 04 Jul 2019 09:13:21 GMT

I have updated the link.

RE: Unable to disable SAADC on NRF52832

t_m — Thu, 04 Jul 2019 08:40:30 GMT

Hello

The link to the Errata page is broken. Can you please send me an updated link. I seem to have similar problem. I do simple floating calculation of adding adc samples in a buffer and calculating the average. The AIN pin stays high (3.3v) during sleep mode.

RE: Unable to disable SAADC on NRF52832

Jørgen Holmefjord — Fri, 29 Sep 2017 08:54:46 GMT

Yes, there seems to be a typo. Thanks for reporting this. Most likelyt this is not implemented in sd_app_evt_wait() since this function is supposed to be general for all revisions of the chip. Not all revisions are affected by the same issues, which is why it is important to allways check the errata sheet for your chip revision.

RE: Unable to disable SAADC on NRF52832

Mike — Fri, 29 Sep 2017 08:36:06 GMT

The errata you linked to appears to have a typo(?)

_set_FPSCR(_get_FPSCR() & ~(0x0000009F));

should probably be

__set_FPSCR(__get_FPSCR() & ~(0x0000009F));

i.e., missing underscores.

RE: Unable to disable SAADC on NRF52832

Mike — Fri, 29 Sep 2017 08:23:12 GMT

Thanks Jørgen, indeed it was the issue. I'd never figured that out.

Are there any particular reasons why sd_app_evt_wait() don't have this fix implemented?

RE: Unable to disable SAADC on NRF52832

Jørgen Holmefjord — Fri, 29 Sep 2017 07:27:05 GMT

Are you doing some floating point calculations in your code? If you are, please check if you are affected by Errata 87 - CPU: Unexpected wake from System ON Idle when using FPU. The current you are seeing indicates that the CPU is prevented from going to sleep mode.