Connection has been established but no response from AT Commands
Use the serial settings 19200-8-N-1 with Flow-Control-OFF. EOL as CrLf.
No response from AT Commands
Please ensure that your TX-RX lines are connected correctly.
At power-on OR after pressing RESET switch on LM551 board (Reset Module / S3), the LM961 sends a power on message on the Serial terminal “SPP+GapCentral_Message_Loop”/”Entering in MessageLoop” depending on the current firmware.
Make sure the EOL setting on Hercules is CrLf before issuing an AT command.
If you were not receiving Power On message before that should be the Tx-Rx connection error.
EOL setting is for issuing AT commands. Refer to the screenshots below for settings in Hercules.