Serial Communication Between Windows and RPi Over Bluetooth

Question

I have tried following a lot of posts online, but I could still not solve my issue.

I want to instantiate serial communication between my RPi and my Windows 11 computer.

Currently, I have connected them over Bluetooth, but I am struggling to create a serial port.

Before I connected, I ran this command: sudo nano /etc/systemd/system/dbus-org.bluez.service, and then added the compatibility flag -C and the SP profile line:

ExecStart=/usr/lib/bluetooth/bluetoothd -C
ExecStartPost=/usr/bin/sdptool add SP

After I connected using the GUI, I ran this on the pi:

pi@raspberrypi:~ $ sudo rfcomm connect hci0 xx:xx:xx:xx:xx:xx
Connected /dev/rfcomm0 to xx:xx:xx:xx:xx:xx on channel 1
Press CTRL-C for hangup

But when I try to create an incoming COM port on my Windows machine, Windows does not pick up on the Raspberry Pi. When I try to create an outgoing COM port on my Windows machine, it says "The device you have selected does not have a serial port service running".

I am not sure where to go from here.

Answer 1

Running bluetoothd with -C and the tool rfcomm are both deprecated and not recommended to use.

The official BlueZ example is at: https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/test/test-profile although it still requires a bit of knowledge to get running.

Another alternative for the RPi would be the Bluedot RFCOMM functionality: https://www.stuffaboutcode.com/2017/07/python-bluetooth-rfcomm-client-server.html.

It can also be done with standard Python sockets. For example: https://stackoverflow.com/a/62815818/7721752. There is also this useful blog https://blog.kevindoran.co/bluetooth-programming-with-python-3/