Nucleo L432kc 5V power

Electronics and hardware Boards
1

Hi everyone,

I’m currently powering a Nucleo-L432kc from the 5V pin with an external battery. I previously used a pullup resistor to prevent the unpowered ST-LINK from holding it under reset but I’ve now opted to remove SB9 to circumvent this as the additional power consumption was unnacceptable in my case. This has worked nicely however I am now unable to load new programs onto the board, with it stuck running the last blinky test program I loaded. I should add that I was able to program it a few times after I removed the solder bridge before I began receive errors.

I receive a “pyocd deploy failed” error in MBED studio and STM32Cube is unable to detect the device.

2

Hi all - I’m having the same issue here and noticed some discussions have been around, since a while, over the same subject (see this one for example: ST Community)
Requirements are quite straightforward: use external power when USB is not used, still make the internal ST-Link usable when USB is connected.
So, I wonder if a permament and efficient external power solution is ever possible, straight out of the box, or if some external circuitry is needed. If so, does any source or reference exist?

Thanks
Fabio