Why, (voltage)

Hi

I would like to measure the voltage of an
1 cell Lipo. Why doesn’t this work with
this sketch?

int val = analogRead(1);
voltage = (5.0 * val3)/1.024;

it always shows me 4995 what means 4.9V but the
lipo has a voltage of 3.94V

Bat+
|
|
R1=1K ohm
|
Analog Pin 1

Bat-
|
|
GND

Thx
Geko

val != val3 ?

Shouldn't it be:

int val = analogRead(1);
voltage = (5.0 * val)/1024;

You're dividing by 1.024 (that is one and 24 thousandths).

Andrew

yeah ok I forgot to change val to val3 in this code but not in the real sketch! I got the mistake. It is my Battery configuration: It should look like this: Bat+ | R1 | Arduino 1 | R1 | Bat-

Thx Geko