• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 84 subscribers
  • Views 880 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

Problem of C2000 LaunchPad GPIO12 Pull-Down

Kelvin Leung
Prodigy 20 points
Other Parts Discussed in Thread: CONTROLSUITE, LAUNCHXL-F28027

I am working on the C2000 launchpad and experienced a problem in EpwmTZ example in controlsuite.  I measure the voltage of GPIO12 which is 1.218V.  It seems that the on-board 10kohms pull-low resistor is not small enough to pull-down voltage at GPIO12 completely.  The datecode of my launchxl-f28027 is 1227.  I tested 2 boards and both show same symptom.  Is it a real problem or I made a mistake of understanding the design of this section? 

Kelvin

  • 0
    Intellectual 695 points

    Have you tried making the measurement while holding the part in reset?  or looked at it with a scope?  

  • 0
    TI__Mastermind 22025 points

    Kelvin,

    Good catch!  I hadn't noticed that myself, but it appears to be a real issue.  The reason you are seeing the 1.2V on the pin is because of the internal pullups.  By default each pin has an internal pullup which is enabled by default.  If you disable this pullup, you should see the voltage go down to GND on this pin.  Then, when you push the switch it will go up to 3.3V.

    Trey