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Graduate II
April 30, 2025
Question

RED LED On due to unknown reason!

  • April 30, 2025
  • 3 replies
  • 836 views

I am using STM32F767ZI board for my projects. But due to some unknown reason, the RED led is turned ON in my nucleo board. I am sharing my code along. The code is very simple and I enabled only a single GPIO to be output. Please let me know my mistake! Where am I going wrong. What is my issue.! Also i haven't enable any GPIO that concerns RED Led. Please let me know the answer!

Thanks! 

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    3 replies

    Super User
    April 30, 2025

    @vbk22398 wrote:

    I am using STM32F767ZI board for my projects.  


    Do you mean the NUCLEO-F767ZI ?
    https://www.st.com/en/evaluation-tools/nucleo-f767zi.html


    @vbk22398 wrote:

     the RED led is turned ON  


    You mean LD3 ?

    AndrewNeil_0-1745996819662.png

     


    @vbk22398 wrote:

    due to some unknown reason,  


    Have you tried stepping through your code in the debugger to see exactly when it comes on?

     

    PS:

    You can download the schematics from the 'CAD Resources' Tab on the board's Product Page:

    https://www.st.com/en/evaluation-tools/nucleo-f767zi.html#cad-resources

    Graduate II
    April 30, 2025

    Which LED do you mean?
    Several LEDs on the Nucleo, and some connected to the on-board ST-Link, some at the power supplies...

    Super User
    April 30, 2025

    @LCE wrote:

    Several LEDs on the Nucleo, and some connected to the on-board ST-Link, some at the power supplies...


    Indeed.

    @vbk22398 here's the full list:

     

    AndrewNeil_1-1745998751545.png

    AndrewNeil_2-1745998763482.png

    So there's four LEDs which could possibly show red ...

    AndrewNeil_3-1745998919618.png

     

    vbk22398Author
    Graduate II
    April 30, 2025

    LD3.

    vbk22398Author
    Graduate II
    April 30, 2025

    @Andrew Neil I tried to enter into debug mode but it doesn't start from main, it starts outside main and if i go inside the function, then it opening a function inside the main, whilst the debug is still outside in some random line.!

    Graduate II
    April 30, 2025

    Like it ended up in Error_Handler?

    Or it's just running some completely different code? Double check build completes and you download correctly. 

    Perhaps mass erase and confirm LED goes off.