Hello, I am using the BoostXL-DRV8301 in combination with LaunchXL-F28069M. I am running the unloaded motor with a speed controller at fixed RPM (very stable)
I am measuring the motor Phase 1 current using the existing method in hal.h:
value1 = (_iq)ADC_readResult(obj->adcHandle,ADC_ResultNumber_1); // //9 should be B2
value1 = value1/4096*3.3; //3.3v scaling
I then offset (ie 1.65V) and divide by 0.01 to get the actual current flowing through the 0.01 ohm shunt resistor.
What is happening is that when I increase my supply voltage while keeping the motor speed constant - the DC power supply current decreases but the ADC current measurement value increases (I would expect decreases??) I do not have an explanation for this. Again the motor speed remains constant.
I am pretty sure this is not an issue with the sign/direction as to test I touched my hand to slow the motor down (increasing the torque) and the ADC current measurement increases in the same direction as when I increased the supply voltage.
Any ideas would be appreciated! Thanks.