You can see the ACS712 in the photo above, but for my GP tester, I think I will build it into an old crusty DMM so I can use the rotary switches, banana plugs, and the meter's current shunt.
I've started modifying my previous code to have a much faster sampling rate. Right now I have the loop time down to ~350µs; that includes sampling and summing two ADCs, then running a boundary test on each computed value. From there, the loop runs again if the boundary condition passes and otherwise bails to a fail-safe routine. I was thinking this test case could have a number of case scenarios that would call a variety of actions, such as controlling current flow through a fet...