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SARTHAK KELAPURE
SARTHAK KELAPURE
Associate III
Apr 11, 2018 4:49 AM UTC
Solved

USB DP-DM Pins

Posted on April 11, 2018 at 06:49

I am using STM32L072 on my custom board. I connected DP DM pins on USB connector directly to the DP DM pins on the MCU. I was hoping it gives me a DEBUG UART but it didn't work that way. What could be the problem?

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    Tesla DeLorean
    Tesla DeLoreanBest answer
    Guru
    Apr 11, 2018 8:03 AM UTC
    Posted on April 11, 2018 at 08:03

    Ok, so unless you software implements a USB device the pins will do nothing. With BOOT0 pulled High it should come up as a USB DFU device if I'm looking at the right App Note.

    The Debug UART of the DISCO/NUCLEO boards comes from the ST-LINK device

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    3 replies

    Tesla DeLorean
    Tesla DeLorean
    Guru
    Apr 11, 2018 5:13 AM UTC
    Posted on April 11, 2018 at 07:13

    Did you load any software onto the part? Is BOOT0 pulled HIGH?

    Check VDDA and NRST levels.

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    SARTHAK KELAPURE
    SARTHAK KELAPUREAuthor
    Associate III
    Apr 11, 2018 7:59 AM UTC
    Posted on April 11, 2018 at 07:59

    I flashed a 'HELLO WORLD' firmware which prints HELLO WORLD on UART. The boot0 pin is not pulled HIGH.

    Tesla DeLorean
    Tesla DeLoreanBest answer
    Guru
    Apr 11, 2018 8:03 AM UTC
    Posted on April 11, 2018 at 08:03

    Ok, so unless you software implements a USB device the pins will do nothing. With BOOT0 pulled High it should come up as a USB DFU device if I'm looking at the right App Note.

    The Debug UART of the DISCO/NUCLEO boards comes from the ST-LINK device

    Tips, Buy me a coffee, or three.. PayPal Venmo (See Profile) Up vote any posts that you find helpful, it shows what's working..
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