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T B
T B
Associate III
Jan 29, 2018 11:02 AM UTC
Solved

STM32 Virtual COM Port and BREAK

Posted on January 29, 2018 at 12:02

Hello!

Is it possible to send a UART break (0.3 seconds) over the Virtual COM Port.

It seems that UART break is connected with NRST.

-Thomas

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    Andrew Neil
    Andrew NeilBest answer
    Super User
    Jan 29, 2018 4:08 PM UTC
    Posted on January 29, 2018 at 16:08

    So, if you want the BREAK to reach the target STM32, you'll have to use a separate connection direct to the target's UART pins (and break the links to the ST-Link UART if you want to use those pins)

    A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
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    13 replies

    Andrew Neil
    Andrew Neil
    Super User
    Jan 29, 2018 11:28 AM UTC
    Posted on January 29, 2018 at 12:28

    Is it possible to send a UART break (0.3 seconds) over the Virtual COM Port

    In which direction?

    • PC --> STM32?
    • STM32 --> PC?
    A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
    T B
    T BAuthor
    Associate III
    Jan 29, 2018 12:45 PM UTC
    Posted on January 29, 2018 at 13:45

    PC --> STM32 (The STM32 resets.)

    On the PC I generate the break with RealTerm or with pyserial. Both has the same effect.
    Andrew Neil
    Andrew Neil
    Super User
    Jan 29, 2018 2:12 PM UTC
    Posted on January 29, 2018 at 14:12

    Now I'm confused.

    So you're saying that you are sending a break, and that it causes your STM32 to reset?

    But you don't want the STM32 to reset?

    So why not use the debugger to see what happens when you send that break ... ?

    A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
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