5 years, 11 months ago.

Nucleo F401RE board - External 3.3V - SWD ERROR

Hi, I've just cutted off STLINK PCB from my Nucleo F401RE board and reconnected to the STLINK via SWD pins (CN4).

If I power up the F401RE board with +5V on Vin pin (with JP6 ON and SB2 ON) then STLINK works well and program the MCU. If I power up the F401RE board with +3.3V the board works, the firmware runs, but STLINK won't see the board and says "SWD ERROR".

Is there something that I don't understand?

Please help

1 Answer

5 years, 9 months ago.

"When NUCLEO is power supplied by +3V3, the ST-LINK is not powered thus the programming and debug features are unavailable."


Section 5.3.3