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TMS320F28379D: Inappropriate connection of launchpad jumpers

Part Number: TMS320F28379D
Other Parts Discussed in Thread: LAUNCHXL-F28379D

Hello community!

I am using a LAUNCHXL-F28379D. unfortunately, I have connected the jumpers inappropriately and now the board doesn't work properly. I have supplied 5V and 3.3V externally while the JP1,2, and 3 were connected and JP4, 5, and 6 were disconnected.

Now when I connect the board directly to the PC through USB (JP1,2,3,4,5 are connected and JP6 is disconnected), the DSP works and it executes my code, however, none of the GPIOs are performing correctly. as an example, while the Blinky code is running, the LED is always "ON"!

What should I do? Is it repairable by replacing for example its buffers?

Regards.

  • Armin,

    Most of the folks are out of office due to US holidays. Please expect response by Jan 5 or 6. Sincere apology for late response.

  • Hi Armin,

    Can you toggle other GPIOs and probe them to see if they change state properly?

    The voltage supply contention could have damaged some components. You may be able to repair the board if you can identify and replace (re-solder) the components.

    Can you try the isolated case and use a current limiting power supply (limit to 500mA). Does it work OK in this case? Does the power supply hit the current limit?

    Best,

    Kevin

  • Hi Kevin,

    Thanks for the reply.

    Actually, at this time I don't have access to a controlled power supply in my home. I will check it in the lab. However, I have connected the board to the USB, then I have seen that the output of U17 is 3.24 instead of 3.3. In addition, when connecting the JP1, 2, and 3, when the board is supplying from USB, 5-volt pins provide a lower voltage (4.87 V).

    When I have programmed it, toggling pin 74 (GPIO14) results in a toggle between the 0.3V to 0.5V !

    The DSP IC does not warm up considerably.

    regards

  • Hi Armin,

    OK, I think testing the proper isolation case (removing JP1, 2, & 3 and using an external power supply) should give a better idea as to what is wrong or what is damaged. If the isolated case works properly then you know the F2837x side of the board is OK.

    I found the blog post below on considerations when applying an output voltage to a DC/DC converter. May have some useful information and explain if / why U17 is damaged.

    https://e2e.ti.com/blogs_/b/powerhouse/archive/2017/01/20/can-i-apply-an-output-voltage-to-my-dc-dc-converter

    Best,

    Kevin

  • Hi Kevin,

    Thanks for the reply

    Please don't close this thread. I'm trying to find another launchpad board to compare it's current with that of mine.

    Would you please let me know if the GPIO of the DSP may have been damaged while its core is still working?

    Regards.

  • Hi Armin,

    OK, current consumption may vary depending on what code, if any, is flashed on each device. If more modules / peripherals of the C2000 device are being used then the current consumption will be higher.

    Armin Miremad said:
    Would you please let me know if the GPIO of the DSP may have been damaged while its core is still working?

    Yes, it's possible that only some of the IO buffers were damaged.

    Best,

    Kevin