I'm working on a STM32L031 project, and I need to read 10 digital 0V-3v3 Inputs.
Everything works fine if i'm reading 5 inputs (PA3, PA4, PA5, PA6, PA7). It is also working if I'm reading 5 other inputs (PB3, PB4, PB5, PB6, PB7).
But as soon as I plug both PA3, PA4, PA5, PA6, PA7 and PB3, PB4, PB5, PB6, PB7, it stops working.
I checked using a voltmetre in the 10 inputs config, and 4 inputs don't rise to 3v3, but only 1V.
So It only reads 3 inputs of (PA3, PA4, PA5, PA6, PA7) and 3 inputs of (PB3, PB4, PB5, PB6, PB7).
Would it be a problem of current sinking ? or just a wrong software configuration ?
I tried configuring inputs with and without pull down.
I checked GND is common to every inputs.
Any ideas ?
thanks for your time.