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I need to make an application that communicates through an RFCOMM socket to a Raspberry Pi, without pairing. On the Android side, I have the MAC address of the RPi and I'm trying to connect to the server using this code:

BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
BluetoothSocket mmSocket = null;

    try {
        mmSocket = device.createRfcommSocketToServiceRecord(UUID);
        mmSocket.connect();
        Log.d(TAG, "mmSocket returned");
    }
    ...

UUID is the same as on the server-side, and i've also tried using the createInsecureRfcommSocket method.

On the Raspberry Pi side, I used the pybluez example of an rfcomm server(here is the example)

It once worked but I don't understand why it did or why it doesn't anymore, in the sense that when I tried to initiate the connection from the phone I got a pairing request on the Raspberry Pi without a pairing request on the phone, and the socket object on android had successfully connected.

Does anyone know what I am doing wrong, or any ideas that might help me, and is such a thing even feasible. Thanks in advance.

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1 回答 1

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我发现了这个悬而未决的问题，我认为至少对于我的情况我有一个可行的解决方案。

我需要做的就是调用这三个命令：

sudo hciconfig hci0 piscan 
sudo hciconfig hci0 sspmode 1
sudo hciconfig hci0 class 0x400100

前两行使 RPi 可以从这个答案中被发现，它还声称 RPi 应该自动配对。这对我不起作用。它仍然需要在两个设备上进行 PIN 确认，这对于无头 RPi 来说是不幸的。

在这个答案中找到的第三行至关重要，它允许将 RFCOMM 套接字连接到未配对的 RPi。 有可能改class会让其他BT服务停止工作，不确定，我只需要RFCOMM。

在此之后，以下示例适用于我的 RPI 4B 和我的 Win10 笔记本电脑：

import socket
from contextlib import closing

# MAC address of RPi, can be obtained with `bluetoothctl list` on RPi.
rpi_addr =  'e4:5f:01:7d:8A:A3' 
# 1-32, some might be used already, e.g. 3 for me, in that case bind fails.
channel = 15
def server():

    print("Creating socket")
    with closing(socket.socket(socket.AF_BLUETOOTH, socket.SOCK_STREAM, 
    socket.BTPROTO_RFCOMM)) as s:
        print("Binding socket")
        s.bind((rpi_addr ,channel))
        print("Listening socket")
        s.listen()

        s_sock, addr = s.accept()
        with closing(s_sock):
            print ("Accepted connection from "+str(addr))

            data = s_sock.send(b"Hello from RPi")

def client():

    print("Creating socket")
    s = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_STREAM, 
    socket.BTPROTO_RFCOMM)
    print("Connecting socket")
    s.connect((rpi_addr,channel))
    print("Connected")

    data = s.recv(1024)

    print(f"Received {data}")
于 2022-01-13T10:33:31.250 回答