I am using Oriental's PK-243-03A stepper motor in bipolar series configuration. The driver I am using is TI's DRV8825. I want to measure my motor's current in order to plot a Speed - Current graph. I have figured out a way to measure speed using photo - interrupter, but I am a little confused on how I should measure the motor's current. I have a couple of questions.
The driver IC I am using has an Isense pin in it which uses an Rsense resistor to set current threshold value for my motor, maybe I can measure the current from there somehow, but how?
Or can I attach an ammeter in series with the VMx pin of the driver and measure current?
Is there any tested or proven method for measuring current? I can really use the help.
Thanks in advance!