• State
  • Locked Locked
  • Replies 5 replies
  • Subscribers 82 subscribers
  • Views 512 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LAUNCHXL-F28379D: FCL SFRA example not generating PWMs

GS
Prodigy 30 points

Part Number: LAUNCHXL-F28379D
Other Parts Discussed in Thread: CONTROLSUITE, , DRV8305

I'm trying to run the example from ControlSUITE with two-motor dyno setup. I'm using LAUNCHXL-F28379D with 2x DRV8305 booster packs. I'm following the manual for this example, but I'm stuck already on Level 1.

I've configured the jumpers, changed the power stages to DRV8305 and compiled the example with level 1 settings. When I go to debug and set EnableFlag to 1, it starts to run (IsrTicker is counting). I've verified the graph outputs, they look like in the manual. Then I connected the scope to monitor the PWM output signal on J4 pin 40 and there is no PWM. I've double-checked the peripheral registers: TBCTR is counting, CMPA is changing, GPAMUX1 GPIO0 is set to 01 to generate the EPWM1A output. But the voltage on the pin is constant 0V.

What could be the problem?

  • 0
    TI__Mastermind 27240 points

    Did you check the if the TripFlagDMC was set to 1?

    Were you able to test with the 3phGanInv booster pack?

  • 0
    Prodigy 30 points

    Helo Ramesh,

    Yes, the TripFlagDMC is set (I don't know why - the motor is not connected, so what could trip the overcurrent?). However, I tried to comment the code that sets the flag so it was kept at 0 and nothing changed - still no PWM output on the MCU pin.

    I don't have the GaN booster pack to try. 

  • 0 in reply to GS
    TI__Mastermind 27240 points

    The phase current feedbacks as seen by the MCU CMPSS are supposed to be within a certain voltage range (1.65V+- 1.20V or so) which is considered as the normal safe motor current. If these go beyond these range, CMPSS will generate the TRIP event and turn off the pulses. Suggest to review the booster pack schematic and the launch pad and see the corresponding connections and voltage ranges. Hope it helps.

  • 0
    Prodigy 30 points

    So I reviewed the code and it seems that there is a default current gain setting (x40) that overflows the unsigned int variable with a negative number. Changing the gain to something more reasonable fixed it (at least for the Level 1 - now I have the PWM output). I wasted the whole day debugging the faulty example code!

  • 0 in reply to GS
    TI__Mastermind 27240 points

    Sorry you had to go through this. It is bad and good. There is a time wasted, but it also helped get a sneak of debugging the solution.