nRF51 and nRF52 ADC calibration information

[Masahiro Kondo]

Hello. I have read a topic about ADC calibration (gain and offset error in 0x10000024) of nRF51822 here but I can't find the document describing it. Could anyone point me where the description of this register is (is it part of FICR?)? And also, does nRF52832 have the same register that I can use to adjust gain and offset inside firmware?

Thank you for the help.

[Stefan Birnir Sverrisson]

Sorry for late reply. Yes, +-2% is worst case before any calibration is applied. So if you apply the calibration numbers applied for third revision hardware at address 0x10000024, then you will be having considerably lower error than +-2%. How much lower, I am not sure, the spec does not state how much of the error is a result of temperature changes, but I know that majority of the temperature error is close to the edges of the temperature range of the nRF51 chip, i.e. close to -25 deg C and +75 deg C. So if your device is generally close to room temperature and you apply the calibration numbers, then you should have relatively accurate ADC readings.