I'm using a stm32f407vg board. Suddenly I can't download my code to flash memory. It gives me this error " Debugger - Cortex-M error: no target connected". In options for target > Debug > Settings in SW Device tab I see " SWDIO: Error No target connected".
How can I solve this?
I had this same issue with my STM32F446RE Nucleo board. This is what I had to do to get my onboard ST-Link to talk to uVision again:
-Download the STM32 ST-LINK Utility tool and try to connect to the board.
STM32 ST-LINK Utility: www.st.com/.../stsw-link004.html
-If the Utility tool fails to connect with the board try tying your boot0 pin high, resetting the board, and reconnecting. On my board this meant using one of the extra jumpers from CN11/12 and connecting pins 7 (boot0) and 5 (VDD) together. Your board's User Manual will tell you where the boot0 pin is and might also tell you how to tie it high. If this doesn't work then the rest of my instructions may not work for you.
-Once connected to the board, in Utility go to menu option ST-Link -> Firmware update. A new window will appear, select "device connect". The window will determine if your ST-Link firmware is out dated and give you the option to update it, select "yes>>>>".
-Return to uVision and try flashing to your device again without boot0 tied high.
-If still failing, tie boot0 high again and retry flashing the device in uVision. If this works, then retry flashing with boot0 tied low again.
This worked for me, hope it helps.
This worked, thanks!