What opamp are you using there? I deliberately chose to put the shunt at a lower potential than the µC or
opamp for very good reason - why have you changed this?
Where is the shunt regulator to give 3.3V?
UNI-T:
The grounds are completely separateEDIT
I tried hooking it up the following way and it seems to work.
However since it’s grounded through the power supply it’s a lot of noise. Making it almost impossible seeing the signal.
Is there a way around this or a better solution?
The more I think about these statements the less I understand.
grounds are separate, yet you are picking up noise through the PSU ground (which isn't labelled in the
diagram). It seems to work, yet its almost impossible seeing the signal...
Have you tried my circuit? You can probably subsitute a blue LED for 3.3V zener, BTW