For the complete documentation index, see llms.txt. This page is also available as Markdown.
Autopilot Connections
There are two communication channels between the Jetson and the flight controller: USB and serial. Both are direct board-to-board connections tested up to 3 Mbps.
Type
Jetson device path
Flight Controller
USB
/dev/ttyACM0
USB
Serial
/dev/ttyTHS1
Telem2
We recommend running MAVLink on USB and XRCE-DDS on serial. ARK-OS's defaults do exactly this — see Services.
USB
The flight controller's USB connection is muxed with the external Micro USB port. While a Micro USB cable is connected, the flight controller is disconnected from the Jetson. After unplugging, reboot the Jetson to restore the connection.
For the flight controller's USB to enumerate, its VBUS_SENSE pin must be driven high by the Jetson. This is set in the Jetson pinmux at boot, so it works out of the box.
Serial
The serial connection is Jetson UART1 (/dev/ttyTHS1) to Telem2 on the flight controller, tested to 3 Mbps. When running MAVLink on Telem2, set flow control to off: MAV_x_FLOW_CTRL = 0.
Flight Controller Reset
The Jetson can hard-reset the flight controller via a GPIO reset line. The reset is gated by the nARMED signal — the Jetson cannot reset the flight controller while it is armed.
