STM32WL55JC not connectable, shows f5 error, but led blink works

[Frank Hefter]

I'm not able to connect the

NUCLEO-STM32WL55JC1 board (Updated FW today to V3.J7) to the

STM32CubeMonitor V.1.1.0

Fun facts: Blink connection test works and the firmware is reported correctly in the connection config box.

Error message reads: "not connected | JTAG/SWD error/f5)

In addition: Please fix the copy & paste bug of the Mac version (1.1.0). Known for at least 8 months.

[stephane.legargeant · Accepted solution]

Hello Franck

Many STM32WL examples disable the debug port and enable sleep mode. This is good to optimize power/security,but STM32CubeMonitor is then not allowed to connect with SWD. (I have tested with LoRaWan_AT_Slave)

To have a stable debug connection, the debug must be enabled and sleep disabled :

For this example, in in the file sys_conf.h,

• Set: #define DEBUGGER_ON    1
• Set #define LOW_POWER_DISABLE 1
• Then fully rebuild the project, flash the board

The connection should work.

Let us know if you are able to connect, it can be useful information for many users.

Best regards

Stephane

[Frank Hefter]

Hallo Stephane,

thank you. This was the correct answer.

Regards, Frank