How can i get the Vbat actual value from ADC?

[MQasi.2]

Hello,

i'm using STM32G070, The firmware i have programmed converts the analog voltage to didital using ADC. the code is below:

the values i get from this is :

OUTPUT:

In the datasheet it is mention that a resister bridge for VBAT is 39K ohm which has ratio 3 on VBAT measurement .

so according to this the ADC value should be around 1365 which wil give us a voltage vaue of 1.1 but the result is voltage:0.48 and adc value:600.

please give me any suggestion, whats wrong with it.

thanks in advance.

[S.Ma]

I would do:

1- Configure the ADC and perform calibration if possible

2- Do your Vbat mesurement, the real value you will sense is Vbat / 3., the measurement is respective to Vdda for 2047 full scale 12 bit value. (3.0, 3.3, 3.6V etc... )

3- Run a Vref measurement to deduct VddA value in mV

4- Walk back the path to deduct accurately Vbat.