nrf52 saadc current

RE: nrf52 saadc current

Stefan Birnir Sverrisson — Fri, 01 Jul 2016 09:54:38 GMT

There is an saadc low power example now available on Github. It also includes a lof of explanation on how the low power is obtained, both at the top of the main.c file and in code comments.

RE: nrf52 saadc current

Jorgewu — Tue, 14 Jun 2016 13:39:40 GMT

Hi Kirkus: According the sample I referred, I have not call the function of nrf_drv_saadc_sample_convert(), and I am using the nrf_drv_saadc_sample(). Is any sample codes can be referred ? Thanks..

RE: nrf52 saadc current

kirkus — Tue, 14 Jun 2016 12:25:36 GMT

@Jorgewu I ended up editing the nrf_drv_saadc.c file in the SDK directly. I added TASK_STOP to nrf_drv_saadc_sample_convert() and it works fine without having to use uninit. So here's the code snippet with the added STOP:

uint32_t timeout = HW_TIMEOUT;
while (0 == nrf_saadc_event_check(NRF_SAADC_EVENT_END) && timeout > 0)
{
    timeout--;
}
nrf_saadc_task_trigger(NRF_SAADC_TASK_STOP);
nrf_saadc_event_clear(NRF_SAADC_EVENT_END);

RE: nrf52 saadc current

Jorgewu — Tue, 14 Jun 2016 04:01:06 GMT

I met same problem by SDK 11.0. I want to　decrease the power by deinit SADDC after get the battery level, however the power consumption is increased after I call the function of nrf_drv_saadc_uninit. How can I fix it??

RE: nrf52 saadc current

Airsource Ltd — Wed, 13 Apr 2016 19:41:13 GMT

The answer is devzone.nordicsemi.com/.../ if anyone finds this question first, as I did.

RE: nrf52 saadc current

kirkus — Sat, 09 Apr 2016 17:50:24 GMT

Any updates on this issue? I'm using Rev 1 silicon, release SDK 11.0.0 and release SoftDevice 132 2.0.0 and I'm seeing a constant 2 mA draw as soon as I do nrf_drv_saadc_sample_convert(). I'm only calling it once every minute or so, but it never drops down after that first call.

EDIT: Never mind, saw the answer on another question.

RE: nrf52 saadc current

MartinBL — Fri, 26 Feb 2016 14:05:05 GMT

I believe the extra current you see is the current drawn by the EasyDMA used by the SAADC. EasyDMA draws about 1.2 mA, and added to the 700 uA SAADC current it sums to ~2 mA. Unfortunately the EasyDMA current is not documented anywhere. Nor is the SAADC driver taking it into account and disabling the EasyDMA feature when not needed. The issue is reported internally and a workaround will be available in the final release of SDK V11.0.0.