Program not running when powering from external source

Question

I have an L432KC and to test it, I created a simple blinking program which I uploaded via USB, which works just fine. When connecting my MCU to my external 5V power supply though, my program does not run. Looking at some posts, I found people suggesting to pull down the Boot0 pin to ensure that it loads the user program, I am not able to find the Pin name on the board of the Boot0 pin of the L432KC though.

I'd appreciate it if someone could help me out.
Thanks in advance!

Andrew Neil · Accepted Answer

@DavidL_ wrote:How would I „break“ this link? What exactly does that mean?It's here: The photo in the UM shows a zero-ohm resistor fitted:To break the link, you need to remove that zero-ohm link.There's no need to be particularly careful with it - you don't need to keep it - so just heat it up with a soldering iron until it comes off. @mƎALLEm @STTwo-32 I've noted before that this needs to be better documented:https://community.st.com/t5/stm32-mcus-products/docmentation-of-solder-bridges/m-p/689362 #BreakSolderBridge #SolderBridge #SB

TDK · Answer

You're connecting 5V to CN4 pin 4 and GND to GND somewhere?

Are you relying on the clock from the ST-Link chip? Use HSI instead.

Unlikely BOOT0 is the issue here as it is pulled down by default, unless you've modified solder bridges.

Sign up

Login with SSO

Login to the community

Login with SSO

Scanning file for viruses.

This file cannot be downloaded