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Visitor II
May 11, 2017
Solved

Intermittent USB VCP Com Port

  • May 11, 2017
  • 4 replies
  • 1552 views
Posted on May 11, 2017 at 12:58

Hi,

i designed a flight controller board based on STM32F303. i have a weird problem where each time i assembled a complete board, initially there will be no problem and PC will be able to detect and connect with the board via USB VCP. but after a while, the board will be disconnected and USB VCP com port is not detected.

i have to resolder usb pins (PA11 pin32 & PA12 pin33) or reflow the whole board, test it again, no problem but after awhile USB VCP is missing again. if i repeat the whole reflow & retest eventually the USB VCP missing problem goes away.

the board is a two layer PCB with HASL lead surface finish. did i get a faulty STM32F303 batch or should i have used immersion gold surface finish for better solder connection?

Please help me with this weird problem, thank you.

#stm32 #usb #stm32f3 #vcp
    This topic has been closed for replies.
    Best answer by Nor Muzakkir Nor Ayobv_2
    Posted on May 29, 2017 at 18:07

    Hi,

    i've found the problem. The USB data+ connection was pulled high to 5V with 1K5 resistor which is supposed to be pulled high to 3V3.

    so i changed the resistor with 2K2.

    Thank you.

    4 replies

    Visitor II
    May 13, 2017
    Posted on May 13, 2017 at 22:03

    Hi guys,

    Please help, thank you

    Visitor II
    May 16, 2017
    Posted on May 16, 2017 at 05:01

    Hi guys,

    any advice please? i would very much appreciate it.

    Thank you.

    Visitor II
    May 29, 2017
    Posted on May 29, 2017 at 18:07

    Hi,

    i've found the problem. The USB data+ connection was pulled high to 5V with 1K5 resistor which is supposed to be pulled high to 3V3.

    so i changed the resistor with 2K2.

    Thank you.

    Visitor II
    October 6, 2020

    I'm also looking for the same device to record my game of Golf ball in the ground. Where can I get that?