SparkFun RTK Express Surveying Kit

We generally recommend using your cellular phone as the radio backhaul for RTCM but you can also use your own, higher power radios as long as they support 57600bps. We also recommend logging all data to your phone over Bluetooth. This is as simple as checking a box within SW Maps. But if you prefer to do long surveys, or need to deal with RAWX measurements where a phone will not be present, a microSD card should be purchased (any size up to 32GB).

Please keep in mind that you will need to provide your own mono-pod or tripod as well as a cell-phone type holder for securing the RTK Express to your mono-pod or tripod. We’ve found this style clamp and this style clamp work well. Your mileage may vary.

Note: The L1/L2 antenna has a 5/8″ thread which will fit most surveying platforms. The kit includes a 5/8″ to 1/4″ adapter as well which will fit most camera mono-pods and tripods. You may need additional adapters for your specific equipment.

Features

GNSS Receiver: ZED-F9P

• Concurrent reception of GPS, GLONASS, Galileo and BeiDou
• Receives both L1C/A and L2C bands
• Current: 68mA – 130mA (varies with constellations and tracking state)
• Time to First Fix: 25s (cold), 2s (hot)
• Max Navigation Rate:
  • PVT (basic location over UBX binary protocol) – 25Hz
  • RTK – 20Hz
  • Raw – 25Hz
• Horizontal Position Accuracy:
  • 2.5m without RTK
  • 0.010m with RTK
• Max Altitude: 50km (31 miles)
• Max Velocity: 500m/s (1118mph)

Bluetooth Transceiver: ESP32 WROOM

• Xtensa dual-core 32-bit LX6 microprocessor
• Up to 240MHz clock frequency
• 16MB of flash storage
• 520kB internal SRAM
• Integrated 802.11 BGN WiFi transceiver
• Integrated dual-mode Bluetooth (classic and BLE)
• Hardware accelerated encryption (AES, SHA2, ECC, RSA-4096)
• 2.5 A deep sleep current

Overall Device

• Internal Battery: LiPo 1300mAh with 500mA charging
• Radio Port: 3.3V TTL Serial (57600bps RTCM TX/RX)
• Data Port: 3.3V TTL Serial (115200bps NMEA)
• Embedded OLED Display for available satellites, data logging, and more.
• Push button controls
• Weight: 162g (entire device including battery)
• Dimensions: 132mm x 101mm x 32mm (5.2in x 3.9in x 1.2in)
• 1x Qwiic Connector

GNSS Multi-Band L1/L2 Surveying Antenna

• Gain: 5dBi
• LNA Gain: 40dB
• Reception Frequencies
  • L1: 1555 to 1615MHz
  • L2: 1198 to 1278MHz
• 50 Ohm Antenna Impedance
• Overall antenna weight: 335g
• Bare antenna element weight (including MMCX connector, with RF shield): 160g
• Dimensions: 148 x 55mm
• Waterproof IP67
• Connector: Female TNC

Included

• SparkFun RTK Express GNSS Receiver
• RTK Kit Carrying Case
• GNSS L1/L2 Multi-Band Antenna – TOP106
• Antenna Interface Cable – SMA to TNC (300mm)
• 1/4″ to 5/8″ Antenna Thread Adapter
• USB Wall Charger – 5V, 2A
• USB A to C Cable – 0.8m
• Data Cable
• Radio Cable

Not Included/Optional:

• Camera Mono-pole or Tri-pod
• Phone/Enclosure Holder
• Telemetry Radios – 500mW
• microSD Card – 16GB

Resources

• RTK Express Schematic
• RTK Express Hookup Guide
• TOP106 GNSS L1/L2 Multiband Antenna
• RTK Express Firmware Repo
• RTK Express Hardware Repo
• Certified OSHW: US002050