A problem with using saadc of nrf52832 .config two channel ，only using one channel ，cause reading error data .

[hananddong]

I have a problem here with using saadc of nrf52832 .

The nrfx_saadC_init (), nrfx_saadC_channels_config (), nrfx_saadC_SIMPLE_mode_set (), and nrfx_saadC_buffer_set () functions were executed to set channel 0. Then run nrfx_saadc_init() and nrfx_saadc_channels_config() to set channel 1.（Nrfx_saadc_simple_mode_set () and nrfx_saadC_buffer_set () are not executed this time）. Finally, there was an error reading data from channel 0.  The initialization is shown below.

The function used to triggering  is shown below

[Jared]

Hi,

 

Finally, there was an error reading data from channel 0. 

 Please elaborate. What do you observe, how is there an error?

Also, note that the driver requires you to set the mode again after the channels has been configured with nrfx_saadc_channels_config().

regards

Jared 

[hananddong]

Hi！Jared

The value of the returned data is almost halved and the value is not stable.I now know that I have to set the mode.However, I am a little curious as to why it affects channel 0 when I only configured channel 4 without setting mode.

[Jared]

Hi,

What do you measure? Could you try measuring something stable such as a external voltage from a bench top supply?

regards

Jared