ST-Link "No target found" error on STMF303RE

[DAppi.1]

Recently bought an STM32F303RE and when I power the board through USB and try to use the STM32CubeProgrammer to connect to the board I get the error: "Error: No STM32 target found!.".

 

When using the STM32CubeIDE to program the board I get a similar error:

"Error in final launch sequence:

Failed to start GDB server

Failed to start GDB server

Error in initializing ST-LINK device.

Reason: (4) No device found on target."

I'm on Windows 10 and already downloaded the ST-link driver (STSW-link009, https://www.st.com/en/development-tools/stsw-link009.html) and have upgraded to the latest ST-link firmware through the CubeProgrammer (V2J38M27).

If I'm understanding correctly, the ST-link can't talk to the MCU for some reason? Anyone have an idea of what I'm missing? Thanks

[TDK · Accepted solution]

Your board is just sitting on top of the breadboard and not plugged into it, right? Seems like a bad idea to have that on a breadboard as it doesn't take much for pins to connect to each other.

It's reporting a voltage of 4.8V, which is way outside of the allowable range.

[DAppi.1]

Yikes this is embarrassing haha. I had it connected to the breadboard and just assumed the bottom pins weren't used for anything but that. Didn't realize the voltage was supposed to read 3.3V. Should have read the user manual more closely, lesson learned! I took it out of the breadboard and just like that it connected properly and the voltage is at the correct reading. Thank you for correcting my mistake!

[TDK]

Glad you got it fixed! Everyone makes dumb mistakes in electronics, it's just part of the job.
I would have expected 4.8V to kill it and am surprised it still works. U5V goes right into VDDA if you plugged it into the board.