Today I tested a DC driver with a STM32 MCU. The schematic is like this:
I have a problem with the ENABLE Signal between the DRV8840 and the MCU.
When the DC Motor is disconnected, I toggle the EN pin and I can see +12V and -12V alternatively on the out pins of the DRV8840. Everything is OK.
When the DC Motor is connected. The MCU init is OK. When I set the EN Signal, the motor runs. But when I ask to toggle the EN Signal, it keeps 3.3V and the motor can't stop.
I can't toggle the EN Pin when the motor is running. WHY?
I don't understand why. My GPIO Pin is configured as Push Pull Output.