Hi，guys. I have a problem when dealing with NRF52's SAADC using nRF5_SDK_13.0.0_04a0bfd. The problem is after downloading and run the program using JLink, everything works fine, the values sampled by SAADC have little jitters. But if we shutdown NRF52 then power it on, sampled results get large periodic jitters. Below are two plot pictures contains the raw data sampled by SAADC in two situations with 500HZ sample rate.The input signal is 5HZ sin wave, you can see from the first figure that the sampled signal is just ok, but the second has large jitters. The only difference is we issued a power on sequence in the second situation. In all situations we usenrf_drv_saadc_sample_convert to get the adc result. the configuration of saadc is single end, 1/6 gain,burst enabled and 4x oversamle.
Another thing is that, when we use nRF5_SDK_12 with ppi and DMA, there're no such jitters in whatever situation. Any suggestions to figure out such problem? Thanks!
