AnsweredAssumed Answered

STM32F407 ADC measurement to Voltage

Question asked by Dark Angel on Mar 29, 2016
Latest reply on Mar 29, 2016 by Dark Angel
Dear Friends,

I have a good experience in STM32F103, but trapped in STM32F407's ADC two weeks already. My HW plateform is STM32F407VGT.
Vref+ connect to 2.048V;   Vdda  connect to  3.1V
ADC resolution configured to be 12bits

Questions :
1. I can read and transfer ADC value to AdcValue, how to calculate to transfer ADCvalue to proper voltage? Is the formula :
  1-1. AdcValue x 3.1 / 4095... or
  1-2. AdcValue x (3.1 - 2.048) / 4095 ...or
  1-3. AdcValue x (2.048 -1.8) / 4095 .....or
  1-4. There is another proper formula..

Because I cannot find the proper reference in two weeks searching, while reading ADC-CH17, Vref (2.048V)  internal channel,  AdcValue is around 400.

Outcomes