Serial communication with arduino over bluetooth

Question

I am using rfcomm to connect to an Arduino nano (HC-06 bluetooth module) from my RPI 4B+. It works flawlessly and the two devices are able to communicate with no issues. I need to be able to connect several of these same bluetooth devices over bluetooth and communicate with them serially. Right now, I have to manually connect each device like this:

sudo rfcomm connect 0 98:D3:41:FD:6B:EB Connected /dev/rfcomm0 to 98:D3:41:FD:6B:EB on channel 1 Press CTRL-C for hangup

And I can communicate perfectly with each device very easily using python:

import serial s = serial.Serial("/dev/rfcomm0", 9600) s.write(bytes("0",'utf-8'))

This works fine for one device, but I would like each device to connect automatically on startup without myself having to initialize anything. How can I use rfcomm to connect and communicate with multiple devices over serial? I simply want my rpi to pair with each device on startup and be ready for communication.

Answer 1

I think the Python Socket module can do this https://docs.python.org/3.3/library/socket.html.

Not many documented examples, maybe this socket client would be a good example to follow: http://blog.kevindoran.co/bluetooth-programming-with-python-3/

There is also a useful API in the Blue Dot library:

https://bluedot.readthedocs.io/en/latest/btcommapi.html#bluetoothclient