Forward Bluetooth socket to serial port

Question

I've been trying to figure out how to turn my Raspberry Pi into a USB to Bluetooth serial adapter. I want to be able to send data over Bluetooth to the Pi which has a USB thermal printer registered at /dev/usb/lp0.

Using only standard command line apps such as hciconfig, hcitool, rfcomm, and sdptool I have been able to see the Pi as visible, and pair to it from an Android tablet using a Bluetooth SPP app on the Store. However, the tablet disconnects immediately, and no data is sent. rfcomm listen /dev/rfcomm0 1 also waits for a connection forever.

I think I'm able to achieve what I need without custom code, using solely standard command line apps, but I'm not entirely sure. socat will likely be of use to finally connect the sockets.

Answer 1

Figures that I'd get it right after posting. To anyone else looking to do something similar:

1. Pair with bluez-simple-agent
2. Create your serial port channel with sdptool add --channel=x sp
3. Listen for a connection on that channel with sudo rfcomm listen /dev/rfcomm0 x
4. Cross the streams with socat /dev/rfcomm0 /dev/usb/lp0

Beautiful. It's all so simple now.