PX4 Instructions

The ARK G5 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 G5 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
UAVCAN_ENABLE	2	Enable DroneCAN with dynamic node allocation
UAVCAN_SUB_GPS	1	Subscribe to DroneCAN GPS messages
UAVCAN_SUB_MAG	1	Subscribe to DroneCAN magnetometer messages
EKF2_GPS_CTRL	7	Enable GPS fusion (lon/lat + alt + 3D velocity)

Optional

Parameter	Description
UAVCAN_SUB_BARO	Set to 1 to subscribe to DroneCAN barometer messages
UAVCAN_SUB_IMU	Set to 1 to subscribe to DroneCAN RawIMU messages.
EKF2_GPS_POS_X / EKF2_GPS_POS_Y / EKF2_GPS_POS_Z	GPS offset from the vehicle center of gravity (meters)

CAN Node Parameters

The node publishes GPS, magnetometer and barometer data with its default parameters. To terminate the bus, fix the node ID, publish IMU data or change the receiver's output rate, PVT modes or dynamics model, see Node Parameters.

---

Dual Antenna Heading Configuration

The G5 provides yaw estimation using two GNSS antennas on a single DroneCAN node. The mosaic-G5 module computes the heading and reports it over DroneCAN.

Hardware Setup

• Connect the ARK G5 RTK Heading GPS to the flight controller's CAN port using a standard 4-pin JST-GH cable

• Connect an antenna to MAIN (SMA) and one to ANT2 (U.FL), through an SMA-to-U.FL cable

• 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
UAVCAN_SUB_GPS_R	1	Subscribe to DroneCAN GPS relative (heading) messages
EKF2_GPS_CTRL	15	Enable GPS fusion + GPS yaw (lon/lat + alt + 3D velocity + yaw). Overrides the value of 7 from the single GPS configuration

Antenna Mounting

The node reports the heading of the MAIN→ANT2 baseline. Set where the antennas are mounted on the flight controller:

PX4 version	Parameters
v1.18 and earlier	EKF2_GPS_YAW_OFF: clockwise angle in degrees from the vehicle forward axis to the MAIN→ANT2 baseline (0 if ANT2 is directly ahead of MAIN, 90 if ANT2 is to the right)
main	SENS_GNSSn_HDG 2 (Dual antenna) in the GPS's slot (SENS_GNSSn_ID, n = 0 for a single receiver), SENS_GNSSn_OFFX/Y/Z the position of MAIN and SENS_GNSSn_AUXX/Y/Z the position of ANT2, in meters in the body frame

PX4 v1.17 and earlier use the heading only while the position is RTK fixed.

CAN Node Parameters

On the P6 and P8, set SEP_ANT_MODE to 2 and reboot the node. The P3H ships with dual antenna saved in the receiver and needs no change. The node reports a heading only with fixed ambiguities. To disable heading (SEP_DUAL_ANT 0), see Node Parameters.

---

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 offset — check the Antenna Mounting parameters against the actual MAIN and ANT2 positions.

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