Are you using STLINK or DFU upload (no USB on Qvadrans)?
If STLINK: you need to have nRST (PG10) connected to the STLINK, it looks like it’s on a different header for the board than the SWD pins (PA13/14)
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Yeah, Im using stlink with SWO, SCLK, nRST, GND, and VCC (3v) connected with my stlink V3Mini, & no usb on the Qvadrans. When i pull that pin to ground manually it resets, so im not sure why pio is having trouble there. Pretty much every time i go to upload it gets that failed to reset error. The ST-Link utility works without any problems most of the time, excepting the occasional error that goes away when i try again.
PIO doesn’t seem to use “connect under reset” by default, so the nRST is not used. The STLink utility can be configured to use connect under reset. So one works, the other (PIO) doesn’t.
Try looking here for a way to change the PIO script to use “connect under reset”
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I found this:
So actually I guess the reset is actually set via SWD protocol, not pulling nRST low, unless you have “connect under reset” configured (you learn something every day!).
I don’t know why this works for me and not you - are you sure your STSTM platform in PIO is up to date? You can run pio update or pio upgrade from the command line and it should update some stuff, in case you’re running an old platform. Are you on Windows?
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You got it again - my PIO core was up to date and I’d checked that before, but I missed updating my STSTM platform. After that updated, uploads work without any problems 
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my PR to STSTM platform for adding generic G431 was merged today 
so it should be easier in the future to use this chip. No need for .json board files or any special config.
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