Now I have assembled a Rsense current testing setup. I found that 0.1 Ohm is not a good choice, because noise is 50mV. Finally I used 0.5 Ohm For 5 Ohm load and current around 2A. Rsense output of 1.1V looks good. This time is only pilot DC V testing. Next step is to measure DC motor and Stepper motor driver current, both chopper and non chopper mode.