Use ST32_Programmer_CLI for monitoring the serial port.

[ubaldot]

I am using the following command

./STM32_Programmer_CLI --connect port=/dev/cu.usbmodem103 P=none

but I get the following error:

Error: Activating device: KO. Please, verify the boot mode configuration and check the serial port configuration. Reset your device then try again...

However, if I add "console" at the end of the above command I can connect and I can write/send files but i cannot read. 

How to fix that? 

[shiwasreet]

Maybe try setting the boot pin high. in my case, i set the rtsEnable to high and dtrEnable to high and then low and then send "7F" command. if it replies back "79", it's in boot mode. maybe different as per your board.