Basics
# scan peripherals
service bluetooth start
hcitool scan
# or
bluetoothctl scan on
# connect
rfcomm bind 0 $mac $channel_nb
rfcomm bind 0 $mac 6
# connect to the peripheral on channel 6
# AT terminal
AT*ESIL=1 # activates silence mode
AT+CMGS="+336875648" # sends SMS