MP6602 No Power to Motor while No Fault Condition

Apologies about the delayed response to your issue! Your patience is much appreciated.

After reading through all of what you have described, there are problems with SPI communication with the MP6602. The device seems to be enabled with the TSTP register advancing when using Ctrl.EN. Having no power to the motor even now really is puzzling. I am sure there are updates that you will have upon this response, but here are some things that I would recommend looking into:

  1. Ctrl.En and the EN pin work in tandem. If the external pin is low while Ctrl.EN is set, the device may not output to the motor. Given the behavior that you have described, try setting Ctrl.EN and the EN high as a combined enabled signal.

  2. While debugging, placing a voltmeter at xOUT1 and xOUT2 pins to monitor any small or fluctuating voltages would be useful in the sense that any small changes could show waveforms of incomplete enable or state drive signals. If these voltages are still absolutely 0V, then the MP6602 is not applying any drive signals at all.

  3. Another avenue of debugging lies in togging the Ctrl.EN pin by toggling low and observing any of the xOUT pins if this triggers any activity. Or you may enable the driver purely with Ctrl.EN while keeping the EN pin low. This may help isolate as to whether the EN pin or Ctrl.EN has some sort of gating effect that is preventing power output to your motor. Also in parallel, please conform

  4. If the xOUT pins are energized upon checking, the motor should atleast show signs of holding torque, even without stepping. Try gently turning the motor shaft to feel for any resistance. Also in parallel, please confirm that the motor winding resistance and connections are correct as an open winding may prevent current flow, even if the xOUT pins show they are outputting power.

  5. It is possible after checking all previous possible errors that there may be some issue with the protection logic of the MP6602. Overcurrent and undervoltage conditions may be active while not visibly triggering a fault. Re-check the VCC bit (which was previously cleared after resetting) and confirm that this remains clear after all setup steps.

In summary, I feel that the issue lies in the initialization sequence as opposed to the MP6602 IC itself. Working with the EN and Ctrl.EN, checking the xOUT voltage pins, and confirming motor connections / winding continuity will help further narrow down this debugging process in identifying issues with the enable signal logic or if there are any unwanted / unintended limitations by the internal protection

If these steps don’t yield fruitful steps in debugging, please contact MPS Now Support for more prompt and in depth help with this issue.

Also it would be good to monitor how the following post turns out as Steve comes back with an update:

Blockquote MP6602 Current Protection trips at 100mA - Motor Drivers/Sensors - Monolithic Power Systems’ Technical Forum

Thank you,
Krishan