AnsweredAssumed Answered

My vdd readout is high. Using Vrefint ADC channel.

Question asked by Sandaker_Palm.He.001 on Jan 4, 2017
Latest reply on Nov 13, 2017 by Taras Chornenkyi


My vdd calculates to 3.49V but I measure it to 3.30V with a voltmeter.

The Vrefint calibration value at 0x1FFFF7BA is 1550.

The ADC value I read is 1465, fluctuating +/- 1.

Calculation is 3.3V * VrefintCalValue / AdcValue = 3.49V

I'm guessing it's my adc read value that is off, not the factory calibration value?


MCU is STM32F042G6Ux. ADC code is done in CubeMX.

ADC is clocked with a prescaler of /4 and sampletime is 239.5 cycles. So all signals should have plenty of time to settle between samples.


Code is inside this link -> Link to code