{"title":"SparkFun GPS-RTK Dead Reckoning pHAT for Raspberry Pi","handle":"sparkfun-gps-rtk-dead-reckoning-phat-for-raspberry-pi-1","url":"/products/sparkfun-gps-rtk-dead-reckoning-phat-for-raspberry-pi-1","description":"The SparkFun GPS-RTK Dead Reckoning pHAT brings high-precision GNSS positioning with automotive dead reckoning to the Raspberry Pi. Built around the u-blox ZED-F9R module, it fuses GNSS measurements with an integrated 3D IMU (accelerometer and gyroscope), wheel ticks, and a vehicle dynamics model to maintain accurate positioning even under poor signal conditions.\n\nThe 184-channel ZED-F9R receives GPS, GLONASS, Galileo, and BeiDou signals on L1 and L2 bands, achieving 10 mm horizontal accuracy with RTK corrections. Position updates run at up to 30 Hz, and dead reckoning maintains continuous positioning through tunnels, parking garages, and urban canyons where satellite signals are blocked or degraded.\n\nPre-soldered headers allow the pHAT to stack directly onto a Raspberry Pi or any single-board computer with a 2×20 GPIO header (including NVIDIA Jetson Nano and Google Coral). Communication uses the Pi's serial UART by default. A Qwiic (I²C) connector and additional 2.54 mm breakout pins are also available.\n\nKey Features\n\n\nu-blox ZED-F9R Module – 184-channel multi-constellation GNSS receiver with integrated 3D IMU for dead reckoning\n\n10 mm RTK Accuracy – Centimetre-level horizontal positioning with correction data (rover only; requires base station)\n\nDead Reckoning – Continuous positioning through signal loss using sensor fusion\n\n30 Hz Navigation Rate – High-rate position updates for real-time applications\n\nDual-Band Reception – L1C/A and L2C for improved accuracy and faster convergence\n\nPre-Soldered Headers – No soldering required; stacks directly onto the Pi GPIO header\n\nOnboard RTC Battery – Reduces time-to-first-fix from ~24 s (cold) to ~2 s (hot start)\n\nU.FL Antenna Connector – Use with an external active GNSS antenna\n\nQwiic Connector – I²C interface for additional peripherals\n\n\nSpecifications\n\n\nConstellations – GPS, GLONASS, Galileo, BeiDou (concurrent)\n\nHorizontal Accuracy – 10 mm with RTK\n\nVelocity Accuracy – 0.5 m/s\n\nHeading Accuracy – 0.2°\n\nTime Pulse Accuracy – 30 ns\n\nMax Navigation Rate – 30 Hz\n\nOperational Limits – ≤ 4 G, 80 km altitude, 500 m/s velocity\n\nProtocols – NMEA, UBX, and RTCM over UART\n\nVoltage – 5 V or 3.3 V (all logic is 3.3 V)\n\nCurrent Draw – ~85–130 mA (varies with constellation tracking)\n\nBoard Dimensions – 65.0 × 56.5 mm\n\nWeight – 20.7 g\n\n\nSoftware Features\n\nConfigurable via u-blox u-center (Windows)\nGeofencing, odometer, and spoofing detection\nExternal interrupt and pin control\nLow power mode\n\n\nIdeal For\n\nAutonomous robotics and vehicle navigation\nPrecision positioning in urban environments\nFleet tracking with dead reckoning through tunnels and covered areas\nRaspberry Pi-based GNSS data logging\n\n\n\nImportant: An external GNSS antenna with U.FL connector is required (not included). The ZED-F9R operates as a rover only — a base station or correction service is needed for RTK accuracy.\n\n\nPackage Contents\n\n1× SparkFun GPS-RTK Dead Reckoning pHAT (v1.1)\n\n\nResources\n\nHookup Guide\nSchematic (PDF)\nEagle Files\nBoard Dimensions\nZED-F9R Datasheet (PDF)\nProduct Summary (PDF)\nIntegration Manual (PDF)\nu-blox Interface Description (PDF)\nu-blox ECCN (PDF)\nGPS Python Module (GitHub)\nPython Module Documentation (ReadtheDocs)\nHardware Design (GitHub)\n","vendor":"SparkFun","product_type":"physical","in_stock":true,"options":[],"variants":[{"id":1220,"title":"Default Title","sku":"SF-GPS-21305","mpn":"GPS-21305","price":719.95,"on_sale":false,"in_stock":true,"available_quantity":76,"option1":"Default Title"}]}