[EE]: Bi-Directional 20A current shunt Using Single supply OPAMP

I would like to condition the output of a 1.1mV/A current shunt to drive
the analog input of a WEMOS D1 Mini (0 - 3.3V).

The target application is easy monitoring (wifi) of anything 12V with an
Anderson plug. i.e. Vehicle to Caravan charge line, Solar Panel to Battery,
Battery to Electric Blanket/Fridge etc.

The device is to be powered from the circuit it is monitoring which will be
around 12.8V.

I am a long way from a bench so have resorted to LTspice.  The attached
circuit (5KB so I hope it gets thru) appears to behave exactly as desired.

However, 2 diodes in series to raise the reference to allow for the
negative swing seems to work in LTspice but I am curious what others think
about this approach.


Justin