hcitool scan

Then, use the rfcomm command to connect to the specified MAC: (it must be as root):

sudo rfcomm connect /dev/rfcomm0 AA:BB:CC:DD:EE:FF 1

This will create the rfcomm0 file inside your /dev/
Now just use any terminal to write to and read from it:

picocom /dev/rfcomm0

or just write to it using echo:
echo “Test” >> /dev/rfcomm0

no baud-rate information is needed, as is the Bluetooth that dictates the speed