Voltage output from analogRead


I'm pretty new to this, so maybe this is a simple question. I'm wondering how I can get the output from the analogRead in volts. I have a gyroscope (IDG1215) with a sensitivity of 15 mV/°/s, bias of 1.35V and working on 5V. I know that the analogRead() function returns a value between 0 and 1023. But how do I get the voltage from that value?


Each count represents 5 / 1023 volts. (unless you’ve set a different analogue reference)


So the same with my accelerometer that is working on 3.3V:

Value(in V) = analogRead()*3.3/1023?

Only if you have 3.3V as your analogue reference.

No, I dont have analogue reference.

Yes, you do. It is almost certainly 5V.

Ah! I get it now!

Thx for the help!

Look in the reference area and read the cautions on AREF.