Hi,
I am using custom board (nRF9160) and zephyr V2.6 and I would like to make sure that I understand the ADC settings correctly in the device tree:
channel@1 {
reg = <1>;
zephyr,gain = "ADC_GAIN_1_4";
zephyr,reference = "ADC_REF_VDD_1_4";
zephyr,vref-mv = <845>;
zephyr,acquisition-time = <ADC_ACQ_TIME(ADC_ACQ_TIME_MICROSECONDS, 3)>;
zephyr,input-positive = <NRF_SAADC_AIN3>; /* P0.16 */
zephyr,resolution = <14>;
zephyr,oversampling = <8>;
};
1- "ADC_REF_VDD_1_4"; means I am using the board power supply as a ref ? it is 3.38V
2- vref-mv is 3.38 / 4
3- oversampling = <8>; is this the sampling rate ? so every time I execute adc_read_dt function, 256 samples will be collected ?
4- I am measuring the voltage every 100ms once, is ADC_ACQ_TIME_MICROSECONDS, 3 considered suitable ?
5- when the voltage is 33mV the ADC reads it as 23mV, I measured the physical pin and it is 33mV, why such difference ?
