TNC-X for the Beaglebone Black
TNC-Black is a special version of TNC-X designed to interface directly with the Beaglebone Black computer. Like the Raspberry Pi, the Beaglebone Black is an inexpensive single board computer. But the BBB has a beefer processor with better graphics and MUCH more I/O. It can be configured to connect to any one of four available serial ports on the BBB, so it is possible to stack four TNC-Black's on the same Beaglebone Black. You can also connect the TNC to the BBB using it's I2C bus, which will allow even more TNC's to be stacked.
The firmware for TNC-Black is based on the original TNC-X code by John Hansen, W2FS as modified by John Wiseman, G8BPQ to support the I2C protocol as well as the original serial port connection.