2011-10-09 04:49 AM
We are currently evaluating STM32F103 series as replacement in a current product, and it was quite a surprise to discover no ADC Vref pin is present in the smaller packages. It is internally connected to Vdda ( supply ), which in our case is not very accurate ( 3.0..3.6 V ).
Is there a clever way to overcome this without using a larger package ? #adc2011-10-09 08:53 AM
Connect one channel of ADC to a precision reference (e.g. 2.5V) and use the measurement from this to calibrate your other channels in software. I did this on our last project and it worked nicely.
2011-10-09 10:00 PM
This is not a bad solution. I also noticed the internal 1.2V ref is readable by the ADC. I think we will continue with this.
Thanks Trevor2011-10-10 02:12 AM
I remember the internal ref not being accurate/stable enough for what we needed at the time. Can't remember figures but worth checking before you commit to using it.
2011-10-11 08:05 PM