Beaglebone Black

The AlarmDecoder AD2PI also supports other embedded systems that can use TTL RS-232 such as the BeagleBone Black. It's a fairly simple process to wire everything up and configure the BeagleBone to communicate with your device.

What you need

  • An AlarmDecoder AD2PI
    • NOTE: The AD2PI pictured is a development board with an extra long pin header. You'll need to solder the connection or go in through the bottom.
  • A BeagleBone Black
  • Wire & solder


  1. Make sure your BeagleBone and AD2PI are disconnected from power and the panel, respectively.
  2. Connect the pins between CONN2 on the AD2PI and P9 on the BeagleBone Black. See the images on the sidebar if you need a visual reference.
    BeagleBone Black
  3. Conn AD2PI CONN2 Pin BeagleBone P9 Pin
    GND 6 1
    3.3V 1 3
    RX 10 11
    TX 8 13
    Note the AD2Pi also supports 5v TTL just provide 5V and it will deliver 5v signals on TX/RX
  4. Connect power to your BeagleBone and boot it up.
  5. Enable UART4:
    • echo BB-UART4 >/sys/devices/bone_capemgr.*/slots
    • Your device should now show up as /dev/ttyO4.
  6. Test your device:
    1. Open the serial port with screen:
      • screen /dev/ttyO4 115200
    2. Confirm communication with the device by rebooting it with =.
    3. Exit screen by typing Ctrl+A+K.
  7. Optional: Enable the overlay at boot:
    • Add capemgr.enable_partno=BB-UART4 to /boot/uEnv.txt
    • NOTE: I've been unable to actually get this to work yet. May be an issue with my kernel.