Projet 03 - float voltage = (sensorVal/1024.0) * 5.0 ;

Other Hardware Sensors
1

Hi
Could someone explain me that line? 1024 ok that 1024 possibilities with 10bits. That all what I understand.

2

More detail would be good, but it looks like an attempt to calculate what voltage was present when checked with analogRead.

3

Replace the "5.0" in that line with the actual voltage powering the Arduino, to get a better estimate of the voltage applied to the ADC input.

Measure it with your multimeter.