Development Guide

Companion Computer for Pixhawk class

Interfacing a companion computer (Raspberry Pi, Odroid, Tegra K1) to Pixhawk-family boards always works the same way: They are interfaced using a serial port to TELEM2, the port intended for this purpose. The message format on this link is MAVLink.

Pixhawk setup

Set the SYS_COMPANION parameter (in the System group) to one of these values.

  • 0 to disable MAVLink output on TELEM2 (default)
  • 921600 to enable MAVLink output at 921600 baud, 8N1 (recommended)
  • 157600 to enable MAVLink in OSD mode at 57600 baud
  • 257600 to enable MAVLink in listen-only mode at 57600 baud

Companion computer setup

In order to receive MAVLink, the companion computer needs to run some software talking to the serial port. The most common options are:

Hardware setup

Wire the serial port according to the instructions below. All Pixhawk serial ports operate at 3.3V and are 5V level compatible.

The safe bet is to use an FTDI Chip USB-to-serial adapter board and the wiring below. This always works and is easy to set up.

1 +5V (red) DO NOT CONNECT!
2 Tx (out) 5 FTDI RX (yellow) (in)
3 Rx (in) 4 FTDI TX (orange) (out)
4 CTS (in) 6 FTDI RTS (green) (out)
5 RTS (out) 2 FTDI CTS (brown) (in)
6 GND 1 FTDI GND (black)