[Paul] knew that he could get an oscilloscope that would measure the microamp signals with the kind of resolution he was after, but it would cost him a bundle. But he has some idea of how that high-end equipment does things, and so he just built this circuit to feed precision data to his own bench equipment.
He’s trying to visualize what’s going on with the current draw of a microcontroller at various points in its operation. He figures 5 mA at 2.5 mV is in the ballpark of what he’s probing. Measurements this small have problems with noise. … Read the rest