Hi,
I'm running an ADC sampling every 8msec, sampling the output value of an op-amp as well as a reference voltage. I subtract the two in firmware. I was implementing the NRF_DRV_SAADC_EVT_CALIBRATEDONE task before starting a data capture session.
However I've notice that over the course of a couple bench tests this SAADC Calibration routine introduces error. I see about a 4.53% variation of a steady state input between Data Collection sessions. If I skip the Calibration Task and just sample the ADC, the variation goes not to 2.91%. Thus the SAADC Calibration is introducing more error at room temperature.
I'm scared to permanently remove this as my device will be used in cold temperatures. But the amount of error introduced is not acceptable in my application. Is this something thats been see before?
I'm using SDK 12.3, SAADC resolution 12bit, 4x oversampling, Buffer size=2, Acquisition Time = 20usec, Gain 1/4.
Thanks guys.
