In a previous post about bluetooth we have seen how to connect to a low cost HC-06 or Sparkfun Mate Gold module connected to an Arduino and establish a serial communication with it using minicom.

In this quick article we will see how to establish connections with two modules and a PC running Ubuntu 16.04.

Scan devices

userk@dopamine:~$ hcitool scan
    Scanning ...
        20:15:12:08:62:95    HC-06
        00:06:66:68:20:61    RNBT-2061

From this command we get the addresses of two modules and their names.

Configure Rfcomm

Edit your configuration file and add the second device. I have just copied the settings for rfcomm0 and changed the name to rfcomm2

userk@dopamine:~$ sudo vim /etc/bluetooth/rfcomm.conf

Bind devices

Make sure that the channels are correct. Here I chose the first channel for both.
Select the device file to associate to each bluetooth module.

userk@dopamine:~$ sudo rfcomm bind 0 20:15:12:08:62:95 1
userk@dopamine:~$ sudo rfcomm bind 2 00:06:66:68:20:61 1

Minicom

Open in two different terminals Minicom as root and save two new configurations blue1 and blue2, the first one listening to port /dev/rfcomm0 and the second to /dev/rfcomm2.

minicom1

Select Serial port setup.

bluetooth

Set the correct ports. And save the configurations as blue1 and blue2 profile.

bluetooth

Exit pressing Ctrl A + X. Now you can connect easily by calling the minicom profile.

userk@dopamine:~$ sudo minicom blue1
userk@dopamine:~$ sudo minicom blue2

Future connections will require the bind command we have seen above.