NUCLEO-L432KC external power how is it done?

[MFrie.6]

I have a NUCLEO-L432KC like the title says and I want to power it from an external source. I am using the ST-Link debugger as an 8mhz clock input, and when the st-link is not powered it pulls the RST pin low and I don't get my 8mhz clock input. I have a 5v power supply going into the 5v pin. SB1 and SB17 are bridged. I am open to suggestions and alternate options.

Thanks

[Piranha]

Update the ST-LINK firmware and read my post there:

https://community.st.com/s/question/0D53W00001t46n6SAA/stm32f767zi-on-external-power-supply-is-stuck-until-reset-button-is-pressed

[MFrie.6]

Ok so I updated the st-link firmware, and the NRST pin is now high if the st-link is powered via usb. Is that 100ms hse timeout configurable? I just feel like I don't understand the problem well enough to ask an intelligent question.

[MFrie.6]

I think now I am starting to understand the 2 second delay after I hooked up a logic analyzer:So if I could just figure out how to delay the hse timeout it could work.

[MFrie.6]

That post was with basically a dumb usb power and this capture is a usb host:

This one has about half a second delay

[MFrie.6]

Changing the HSE timeout doesn't make a difference. How would a person debug this problem?

[MFrie.6]

So here is another capture. The CPU is getting reset after the ST-link starts sending a clock pulse. That doesn't make any sense to me then why it is not booting up. Any thoughts?

[MFrie.6]

I figured out why it wasn't starting when it gets plugged in. You have to put

STARTUP_FROM_RESET

in preprocessor definitions. The catch with it is that you don't want to use it while debugging because the debugger doesn't have full controll with that enabled. I am using Crossworks for arm, so I don't know if it is the same for other IDEs. Now I just have to figure out how to power the st-link from the 5v pin.