I want to amplify a signal with an AD620 inamp and read it on a PC through and Arduino.

This is my simulation in LTSpice that seemed to work quite well:

On a breadboard that could look like this:

This is actually a breadboard layout I design a while ago, but I apparently never did manage to read the output on the Arduino from which it is powered.

Testing in real life:

Between 0 AND 5 Volt, so readable on the Arduino!

After this I connected the Arduino to my laptop (unconnected from mains voltage) and used the Arduino's 5V to power the AD620 chip. This was the result on my laptop:

Next up: can I use a potmeter to change the gain on the fly? Yes, but even near the zero resistance the chart does not go all the way to 0-5 V. Perhaps the AD620 is not a 'rail-to-rail' inamp? I think the answer is no; the datasheet lists some values at 'Output swing' that might indicate that is only goes about as close as 1V to either Vs+ and Vs-.

Later I used an 8.2 V Lilon battery as supply for the AD620 which allowed me a much larger waveform.

Also, a potentiometer worked as a gain set resistor really well.