AnsweredAssumed Answered

STM32F429 External power supply issue

Question asked by mafull on Jul 4, 2016
Latest reply on Apr 10, 2018 by nguyen May
Hi all,

I'm working with an STM32F429 disco board and I can't seem to get it to work with an external power supply (USB cable not plugged in). When connected via USB, everything is functioning as required. I have one of the UART ports setup for PC logging.

When I disconnect the USB cable and power through one of the 5V pins, the LED labelled COM flashes, and the program does not run. Interestingly, a few characters do get sent through UART before it cuts out. It is definitely being supplied with 5V, and the same thing happens when connecting via a USB cable to a basic USB charger (this one is perhaps more understandable since there it probably expects some form of USB communication as opposed to just power).


I have an F407 disco board at home on a quadcopter that is powered from an ESC into a 5V pin - this functions correctly.

Anyone have any ideas?

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