I have minimal linux system (no GUI, raspberry pi like board, based on buildroot) which should be able to do the following:
- Allow all bluetooth clients to pair (no pin) after pressing a button for 60 seconds
- Allow connection using SPP (serial port profile)
- Endpoint of the SPP should be something like /dev/rfcomm
In an older version of buildroot (setup around 2016) I was able to do this using the following commands executed after the button press:
dbus-daemon &
bluetoothd --compat &
hciconfig hci0 up
hciconfig hci0 noauth
hciconfig hci0 sspmode 1
hciconfig hci0 class 0x080500
hciconfig hci0 name foobar
hciconfig hci0 piscan
sdptool add --channel=22 SP
rfcomm listen /dev/rfcomm0 22
I could then pair from my android phone without pin and connect to the SPP interface using this app. Since then hciconfig, sdptool and rfcomm where deprecated. If I try the above method I can't pair from my phone (got connection refused). Without pairing the SPP stuff can't work obviously.
What would be the preferred way in 2021 to setup a headless system which behaves as described above?