如何在不认识的情况下通过蓝牙连接两个设备

Question

I'm writing a python script that is running on a raspberry pi. An android app needs to be able to connect to the raspberry pi through bluetooth and send it some data.

I am not sure how to connect them because the server (pi) will not know the name of the android, and client (application) won't know the address and port of the raspberry pi. Is there a clean solution to the bluetooth connection?

Here is the current server code. The current solution is have the server run on a specific port, but this doesn't seem very clean as the mac address/port may be different each time.

import bluetooth

    hostMACAdress = '' # need to fill this in
    port = 3
    backlog = 1
    size = 1024
    socket = bluetooth.BluetoothSocket(bluetooth.RFCOMM)
    socket.bind((hostMACAdress, port))
        socket.listen(backlog)
        
try:
    client, clientInfo = socket.accept()
    while True:
        data = client.recv(size)
        if data:
            print(data)
            client.send(data) # Echo

Answer 1

The host MAC address in your script on the RPi will be the address of the RPi. You will have to declare a port, but many Android apps eg Serial Bluetooth Terminal will search for the port.

You will need to pair the RPi and the Android phone first. There is a good procedure at: https://bluedot.readthedocs.io/en/latest/pairpiandroid.html

There is an issue on recent versions of the RPi OS where PulseAudio can be using the RFCOMM Serial Port Profile (SPP) so you may have to stop PulseAudio if it is complaining about rfcomm already in use.

Finally, you don't need to use the bluetooth dependency. It can be done using the standard Python socket library. More details at:https://blog.kevindoran.co/bluetooth-programming-with-python-3/