Maybe this question is obvious, but I'll try.
I am trying replicate this potentiostat without R5:
In the interests of calibrating it I've joined the reference and the counter electrode to resistor of 10k ohm in the other extreme of the resistor I've connected the working electrode.
Later I set Ard D9 such as the potential drop was -0.58V measured with the multimeter (with positive pin in CE-RE and negative pin in WE) so the question is:
The current in the resistor as Ohm's law states is the output of the voltage follower V divided by R_6, which must be equal, in magnitude, to 0.58/10000 = 58uA.
How can I measure the voltage in WE with the multimeter? It must stay constant.
I know a little bit more handling Arduino but instrumentation it is too hard for me.