keep lowest power consumption when saadc in no sampling state

[bing]

I am using saadc to periodically sample a voltage (per about 12 seconds). The voltage cannot be shutdown and always is a value neigher zero nor VDD (1.25v, 2.5v, 1.0v, etc.). During the no sampling time, how to change the pin configuration to keep the whole system in the lowest power consumption? I have tried to set the pin to GPIO input (without pullup/pulldown register) and give it its default state by the call driver API nrf_gpio_cfg_default(). Both the 2 methods have no effect to reduce the current consumption.
I am using SDK11 and S132 (2.0.0). And the hardware platform is nrf52832. Is there any suggestion to sovle this problem?

[Jørgen Holmefjord]

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.

[bing]

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?

[Jørgen Holmefjord]

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.

[bing]

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