https://devzone.nordicsemi.com/f/nordic-q-a/24760/writing-in-sd-card-at-fixed-time-intervals-by-reading-from-adcHi, I have successfully sampled my signal using SAADC example at a sampling frequency of 10 Hz. I am using a flag in the saadc_callback() function which I read from the main() function and accordingly instruct to write the sampled data in the SD carden-USTelligent Community 13Wed, 30 Aug 2017 07:38:06 GMThttps://devzone.nordicsemi.com/thread/97520?ContentTypeID=1Wed, 30 Aug 2017 07:38:06 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d0a4efeb-a671-419c-acaf-e934468509efMartinBL<p>Hi, Have you considered using <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/saadc.html?cp=2_1_0_36_5#saadc_easydma">EasyDMA</a> and <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/ppi.html?cp=2_1_0_21#concept_sxf_21l_1s">PPI channels</a>? It is possible to configure a timer to trigger SAADC sampling at accurate intervals and then have the SAADC store the sample in memory without using the CPU. This means that the timer and SAADC can do their thing in the background and your application can process the collected data whenever it has time. In more advanced cases it should also be possible to make the timer trigger SAADC sampling, and then have the SAADC trigger SPI transfers when the sampling is done. However, I&#39;m not that familiar with SD cards, but I imaging that you might have to format the data, and maybe send some commands before being able to store the data on the card, so it might be difficult to do everything in the autonomously.</p><div style="clear:both;"></div>