How to measure current to detect motor stall on H-Bridge driven motor?
Put your current sensor in one of the supply lines that feeds the H-bridge. Either put a high-side sensor in series with the positive supply, or put a low-side sensor in series with its ground connection. Regardless of which way the motor is turning, the current flows through these points in only one direction.







simulate this circuit &ndash; Schematic created using CircuitLab

The advantage of low-side sensing is that your feedback signal is automatically ground-referenced. But you can get ICs from several vendors that make high-side sensing just as easy.

I've shown resistors, but you could instead use a Hall-effect sensor in either position and also get a ground-referenced output.