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Intermittent USB VCP Com Port

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
1 ACCEPTED SOLUTION

Accepted Solutions
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.

View solution in original post

4 REPLIES 4
Posted on May 13, 2017 at 22:03

Hi guys,

Please help, thank you

Posted on May 16, 2017 at 05:01

Hi guys,

any advice please? i would very much appreciate it.

Thank you.

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.

Smo.1
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I'm also looking for the same device to record my game of Golf ball in the ground. Where can I get that?