SparkNavi F9P GPS Module Setup

The SparkNavi F9P module uses a 6-pin connector:

Connecting to SparkNavi Blue GPS1

GPS1 on SparkNavi Blue is an 8-pin connector. The first 5 signal pins map 1-to-1 with the F9P module; pins 6–7 (SAFETY_SWITCH / LED) on Blue are not used by this module.

Connecting to SparkNavi Blue GPS2

GPS2 on SparkNavi Blue is a 6-pin connector — a direct 1-to-1 match with the F9P module.

For a single SparkNavi F9P module connected as GPS1, the default ArduPilot serial settings (GPS UART at 230 400 baud) already work. The key parameters to verify:

After Write Params and Reboot, Mission Planner Status should show:

• gpsstatus ≥ 3 (3D fix); 4 = DGPS, 5 = RTK Float, 6 = RTK Fixed
• satcount typically 20–30+ with clear sky view (multi-constellation)

When using two SparkNavi F9P modules (GPS1 + GPS2), both are identical multi-band F9P units. The recommended switching strategy is Blend.

GPS_AUTO_CONFIG controls whether ArduPilot rewrites the GPS module's internal configuration on boot:

When two GPS units are connected, GPS_AUTO_SWITCH decides which solution ArduPilot uses:

EKF3 also supports GPS affinity with lane switching: an EKF lane can be bound to a specific GPS instance, and the whole lane is switched out if that GPS becomes unhealthy. When GPS_PRIMARY is used for a lane and GPS_AUTO_SWITCH is enabled, the lane will follow the auto-switch decision.

For operations in contested or RF-noisy environments (a common requirement for defense and industrial UAV platforms), ArduPilot provides EKF3 jamming mediation:

Setting EK3_OPTIONS bit 0 (JammingExpected) changes EKF3 behavior such that, when GPS lock is lost for more than 2 seconds and dead-reckoning navigation is possible, the preflight alignment GPS quality checks (EK3_GPS_CHECK, EK3_CHECK_SCALE) must pass again before GPS is re-used.

This prevents corrupted GPS data from being immediately consumed by the EKF after re-lock — a likely failure mode under deliberate jamming or spoofing.

The onboard BMM150 is detected automatically by ArduPilot over the I²C2 bus.

After connecting and rebooting, in Mission Planner Setup → Mandatory Hardware → Compass:

1. Verify detection — the BMM150 should appear as an external compass (typically priority 1 if no other external compass is connected)
2. Disable internal compasses — for best yaw performance, deselect the FC's internal compasses if external compasses are healthy (SparkNavi Blue has no internal compass, so this step is automatic)
3. Set orientation — set COMPASS_ORIENT to match the physical mounting of the GPS module (the arrow on the PCB silkscreen should point toward the front of the aircraft; if rotated, set COMPASS_ORIENT accordingly)
4. Calibrate — perform the on-board or Mag Cal procedure, rotating the airframe through all axes

After full setup, the Mission Planner HUD should show:

• 3D Fix or better within 30 seconds outdoors
• Sat count typically 20–30+ with clear sky
• HDOP below 1.0 within 1 minute
• RTK Fixed within ~35 seconds when a base station / NTRIP correction is active

For RTK operation, set GPS_INJECT_TO = 127 and stream RTCM3 corrections from Mission Planner (Initial Setup → Optional Hardware → RTK GPS Inject) or a custom NTRIP client.

• ArduPilot — GPS, Compass, Optical Flow, and Other Sensors
• ArduPilot — Common u-Blox GPS Setup
• ArduPilot — GPS for Yaw (Moving Baseline)
• u-blox ZED-F9P Product Page
• SparkNavi Blue GPS1 / GPS2 pinout