• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 82 subscribers
  • Views 623 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.

Cannot see PWM pulses with oscilloscope

Don McCune
Intellectual 385 points
Other Parts Discussed in Thread: CONTROLSUITE

I cannot see the PWM pulses with an oscilloscope when I run "epwm_deadband" or "epwm_updown".

I am using a recent version of controlSUITE and CCS version 5.1.0.09000.  I am using the controlCARD TMDXCNCDH52C1 with the XDS100v2 emulator. I am able to load, flash run and debug both programs.

I am probing a pin that has continuity to Concerto pin 5 and comparing it to ground -- in this case I am using pin 3 of J6 on the controlCARD for ground.  I am expecting to see a 3.1 volt square wave, but only see low voltage noise.  In addition to PA0, I have probed PA1, PA2, PA3, PA4, and PA5 while the programs are running and I see nothing on any of them.

The board and the example programs are original and unmodified.

Is there a switch setting that could make a difference?  Does this work for any one else?

  • 0
    Intellectual 385 points

    This problem was solved by running "setup_m3" on the M3 before running the epwm_deadband.

    The following paragraph is in the comment section of spia_loopback_c28.c but is NOT in epwm_deadband_c28.c.  Perhaps it should be.

    //! Before loading this example, execute the setup_m3 project on the Master

    //! Subsystem.  The setup_m3 project is in the F28M35x_examples_Control

    //! directory. This project sets up the PLL and releases the Control

    //! Subsystem from reset.

  • 0 in reply to Don McCune
    TI__Expert 3520 points

    Hello Don,

    Glad you got the example running properly!  For future reference further information on running the examples, what they do, and how to start a new project can be found in the Concerto F28M35x section in controlSUITE under Devices in the F28M35x Firmware Development Package User's Guide.  Under section 3 Control Subsystem Example Applications steps needed to get all the control examples running is explained as well as the need to run the setup_m3 project before loading any control example.

    Hope this document helps,

    Mark-