keep lowest power consumption when saadc in no sampling state

RE: keep lowest power consumption when saadc in no sampling state

bing — Fri, 16 Jun 2017 08:23:16 GMT

Thanks. I tested the example you provided. It is what I want.

RE: keep lowest power consumption when saadc in no sampling state

Jørgen Holmefjord — Fri, 09 Jun 2017 11:14:54 GMT

It is no problem to extend the example to support scan mode and still keep it low power. I have posted an example of how this can be done in this thread. Just make sure you disable oversampling and burst mode, and set the SAADC_SAMPLES_IN_BUFFER define to the number of active channels. The current consumption with 5 enabled channels and the sampe rate of the example (250ms) should be ~6 uA. If you only sample once every 12 seconds, I see current consumption of ~2.4 uA.

RE: keep lowest power consumption when saadc in no sampling state

bing — Fri, 09 Jun 2017 09:42:56 GMT

My current consumption between the two sampling points is larger ~100uA than the state which let the input to the saadc is completely zero and uninit the saadc then put the AINx related gpio pins to output direction with 0 level. And I noticed that, only 1 channel can be used in the example you gived in the GitHub. But in my project, I used 5 channel and the scan mode of saadc. Anyhow, thanks for you comment, I will try just 1 channel to complete sampling the multi-inputs. In addition, what is the best way to change an AIN pin to the using saadc channel?

RE: keep lowest power consumption when saadc in no sampling state

Jørgen Holmefjord — Fri, 09 Jun 2017 09:15:45 GMT

Which current consumption are you having now? In general you should uninit the SAADC periheral between sampling to reduce the current consumption from EasyDMA interface. See this GitHub example.