PX4 Instructions

The ARK G5H RTK Heading GPS can be operated as a single-antenna GPS or with two antennas to provide GNSS-derived heading. Start with the Single GPS Configuration below, then add the Dual Antenna Heading Configuration if you want heading.

Single GPS Configuration

Connect the ARK G5H RTK Heading GPS to the flight controller's CAN port using a standard 4-pin JST-GH cable.

Flight Controller Parameters

Set the following in QGroundControl and reboot the flight controller.

Required

Parameter
Value
Description

2

Enable DroneCAN with dynamic node allocation

1

Subscribe to DroneCAN GPS messages

1

Subscribe to DroneCAN magnetometer messages

7

Enable GPS fusion (lon/lat + alt + 3D velocity)

Optional

Parameter
Description

Set to 1 to subscribe to DroneCAN barometer messages

Set to 1 to subscribe to DroneCAN RawIMU messages.

GPS offset from the vehicle center of gravity (meters)

CAN Node Parameters

Set the following on the GPS and reboot the node. CAN node parameters can be configured using either:

Required

Parameter
Value
Description

CANNODE_PUB_MAG

1

Publish magnetometer messages on the CAN bus

Optional

Parameter
Description

CANNODE_TERM

Set to 1 if this is the last node on the CAN bus

CANNODE_PUB_BARO

Set to 1 to publish barometer messages on the CAN bus

CANNODE_PUB_IMU

Set to 1 to publish RawIMU messages on the CAN bus.

SEP_OUT_RATE

Output rate for GNSS data messages: -1 = OnChange, or 50 / 100 / 200 / 500 ms

SEP_PVT_MODE

Bitmask of allowed PVT modes for Rover operation. Bits: 1 = StandAlone, 2 = DGNSS, 4 = RTKFloat, 8 = RTKFixed. Default 15 (all). The receiver uses the most accurate mode available

SEP_RCV_DYN

Receiver dynamics model: 0 = Static, 1 = Quasistatic, 2 = Pedestrian, 3 = Automotive, 4 = RaceCar, 5 = HeavyMachinery, 6 = UAV (default), 7 = Unlimited


Dual Antenna Heading Configuration

The G5H provides yaw estimation using two GNSS antennas on a single DroneCAN node. The mosaic-G5 P3H module handles the calculation internally and reports the heading over DroneCAN.

Hardware Setup

  • Connect the ARK G5H RTK Heading GPS to the flight controller's CAN port using a standard 4-pin JST-GH cable

  • Connect antennas to both the MAIN and ANT2 SMA connectors

  • Mount the antennas with a minimum of 30 cm separation (more is better for heading accuracy)

Flight Controller Parameters

Apply the Single GPS Configuration flight controller parameters above, then change/add the following in QGroundControl and reboot the flight controller.

Required

Parameter
Value
Description

1

Subscribe to DroneCAN GPS relative (heading) messages

15

Enable GPS fusion + GPS yaw (lon/lat + alt + 3D velocity + yaw). Overrides the value of 7 from the single GPS configuration

Optional

Parameter
Description

Clockwise rotation in degrees from the vehicle forward axis to the MAIN→ANT2 baseline (e.g. 0 if ANT2 is directly ahead of MAIN, 90 if ANT2 is to the right). Equivalent to the SEP_OFFS_YAW node parameter — use one or the other, not both

CAN Node Parameters

Apply the Single GPS Configuration CAN node parameters above, then add the following on the GPS and reboot the node.

Required

Parameter
Value
Description

SEP_DUAL_ANT

3

Enable dual antenna heading. Bitmask: 1 = Fixed (highest accuracy), 2 = Float (more robust), 3 = Fixed + Float (default, recommended — receiver uses best available)

Optional

Parameter
Description

SEP_OFFS_YAW

Clockwise rotation in degrees from the vehicle forward axis to the MAIN→ANT2 baseline. Range: -360 to 360. Equivalent to the EKF2_GPS_YAW_OFFSET flight controller parameter — use one or the other, not both

SEP_OFFS_PITCH

Pitch offset in degrees to compensate for vertical mounting differences between MAIN and ANT2. Range: -90 to 90. A positive pitch indicates the MAIN antenna is mounted lower than ANT2


Troubleshooting

  • Heading not appearing — verify UAVCAN_SUB_GPS_R is set to 1 and reboot the flight controller.

  • Verify antenna separation — ensure a minimum of 30 cm between antennas. Greater separation improves heading accuracy.

  • Yaw alignment — if the antennas are not aligned along the vehicle's forward axis, set the SEP_OFFS_YAW parameter on the G5H node to the clockwise rotation angle, or set EKF2_GPS_YAW_OFFSET on the flight controller.

  • See our GPS Placement guide for mounting best practices, interference sources, and antenna positioning.

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