SparkFun
RTK Express GNSS Surveying Kit
· MPN: GPS-18380
This field-ready kit is made for centimetre-level global positioning measurements using GNSS RTK. It centres on the RTK Express, a Bluetooth® enabled multi-b...
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This field-ready kit is made for centimetre-level global positioning measurements using GNSS RTK. It centres on the RTK Express, a Bluetooth® enabled multi-band GNSS receiver based on the Espressif ESP32 and u-blox ZED-F9P.
The kit is supplied in a carrying case and includes the 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 and Radio Cable.
It works with common GIS software on Android and iOS, and can send NMEA data over Bluetooth or TCP. For RTCM corrections, SparkFun generally recommends using a mobile phone as the radio backhaul, though external higher-power radios can be used if they support 57600bps.
You will need to provide your own mono-pod or tripod and a phone/enclosure holder. The RTK Express is not designed for permanent outdoor mounting; for fixed installations, keep the receiver indoors or protected from the elements and run an SMA cable to the outdoor antenna.
Features:
- SWMaps (Android and iOS)
- ArcGIS Survey123
- Field Genius
- SurvPC
- Survey Master
- Vespucci
- QGIS
- QField (Android and iOS)
- Any GIS software that uses Bluetooth SPP or BLE
- Any GIS software that supports NMEA over Bluetooth or TCP
Specifications:
- GNSS Receiver: ZED-F9P
- Concurrent reception: GPS, GLONASS, Galileo and BeiDou
- Bands received: L1C/A and L2C
- Current: 68mA - 130mA (varies with constellations and tracking state)
- Time to First Fix: 25s (cold), 2s (hot)
- PVT (basic location over UBX binary protocol): 25Hz
- RTK: 20Hz
- Raw: 25Hz
- Horizontal Position Accuracy without RTK: 2.5m
- Horizontal Position Accuracy with RTK: 0.010m
- Max Altitude: 50km (31 miles)
- Max Velocity: 500m/s (1118mph)
- Approximate accuracy out of the box: 300mm
- Accuracy with RTCM corrections: 14mm
- Bluetooth® Transceiver: ESP32 WROOM
- Microprocessor: Xtensa® dual-core 32-bit LX6 microprocessor
- Clock frequency: Up to 240MHz
- Flash storage: 16MB
- Internal SRAM: 520kB
- WiFi transceiver: Integrated 802.11 BGN WiFi transceiver
- Bluetooth®: Integrated dual-mode Bluetooth® (classic and BLE)
- Encryption: Hardware accelerated encryption (AES, SHA2, ECC, RSA-4096)
- Deep sleep current: 2.5 µA
- 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)
- Display: Embedded OLED Display for available satellites, data logging, and more.
- Controls: Push button controls
- Weight: 162g (entire device including battery)
- Dimensions: 132mm x 101mm x 32mm (5.2in x 3.9in x 1.2in)
- Qwiic Connector: 1x Qwiic Connector
- GIS software compatibility: Works with common GIS software including: SW Maps, SurvPC, Field Genius, et al.
- Antenna: GNSS Multi-Band L1/L2 Surveying Antenna
- Gain: ≥5dBi
- LNA Gain: 40dB
- L1: 1555 to 1615MHz
- L2: 1198 to 1278MHz
- Antenna Impedance: 50 Ohm
- Overall antenna weight: 335g
- Bare antenna element weight: 160g
- Bare antenna element weight details: including MMCX connector, with RF shield
- Antenna dimensions: 148 x 55mm
- Waterproof rating: IP67
- Antenna connector: Female TNC
- Antenna thread: 5/8"
- Included antenna thread adapter: 5/8" to 1/4"
- External radio support: 57600bps
- microSD card support: any size up to 32GB
- Certified OSHW: US002050
Optional items not included are a camera mono-pole or tri-pod, phone/enclosure holder, Telemetry Radios - 500mW and microSD Card - 16GB.
Jargon buster
Plain-language definitions for the technical terms used above.
- 3.3V TTL
- 3.3V TTL means the serial logic signals use 3.3 volt levels rather than 5 volts. This matters because connecting it directly to a 5V-only signal can damage the module or cause unreliable communication unless level shifting is used.
- BLE
- BLE stands for Bluetooth Low Energy, a Bluetooth mode designed for low power use and broad compatibility with modern phones and computers. It connects well to battery-powered and mobile devices, including Apple hardware, though it behaves differently from Bluetooth Classic and its serial-style profiles.
- deep sleep
- Deep sleep is a low-power mode where the microcontroller turns off most functions while keeping just enough circuitry active to wake up later. It is important for battery-powered projects because it can greatly extend how long the device runs between charges.
- ESP32
- ESP32 is a family of low-cost microcontroller chips and modules from Espressif with built-in WiFi and Bluetooth. They support programmable firmware and over-the-air updates, and are commonly programmed with toolchains such as the Arduino core and ESP-IDF.
- Galileo
- Europe’s satellite navigation system. Galileo support can improve satellite availability and accuracy, especially when combined with GPS and other constellations.
- GLONASS
- Russia’s satellite navigation system. A receiver that can also use GLONASS has more satellites to choose from, which can improve positioning reliability when the sky view is partly blocked.
- GNSS
- GNSS stands for Global Navigation Satellite System, an umbrella term for satellite positioning networks such as GPS, GLONASS, Galileo and BeiDou. Receivers use these satellites to determine position, and high-precision units can output a steady stream of serial position data.
- GPS
- The US satellite navigation system used by GNSS receivers to calculate position and time. Support for GPS is important because it is widely available and often used together with other constellations for more reliable positioning.
- Impedance
- Impedance is the total opposition a component or circuit presents to alternating current, measured in ohms, combining resistance with frequency-dependent reactance. It appears in many contexts, such as matching a speaker's impedance (for example 4 ohm or 8 ohm) to an amplifier or the input and output impedance of signal circuits, and a correct match helps avoid weak signals, distortion or damage.
- IP67
- An ingress protection rating meaning the enclosure is dust-tight and can survive temporary immersion in water under specified test conditions. This matters when choosing a sensor for outdoor, wet, or wash-down environments.
- L1C/A
- A GPS signal band used by many GNSS receivers for standard positioning. Support for this band helps determine which satellite signals the receiver can use and how well it can maintain a location fix.
- L2C
- A second GPS signal band used by dual-band GNSS receivers to improve precision and reduce errors caused by the atmosphere. It matters for RTK and high-accuracy applications because using two bands can produce faster and more reliable centimetre-level fixes.
- LiPo
- A LiPo (lithium polymer) battery is a rechargeable lithium battery widely used in portable projects because it is light and compact. LiPo cells need correct charging circuitry and careful handling to stay safe, so equipment that supports LiPo generally includes charging or protection hardware suited to that battery type.
- microSD card
- A microSD card is a small removable flash memory card used to store data such as audio, images, logs or program files. Its capacity and formatting (often FAT32 or exFAT) affect how much can be stored and whether the card needs preparing before use.
- OLED
- OLED stands for organic light-emitting diode, a display type where each pixel produces its own light. It matters because OLED screens are thin, high-contrast and easy to read for small status displays, but they can be more sensitive to image burn-in than some other display types.
- PVT
- Position, velocity and time data reported by a GNSS receiver. Knowing the PVT update rate helps you judge how often the board can provide basic navigation information to your project.
- Qwiic
- Qwiic is a plug-in connector system for I2C devices that uses small 4-pin cables, so you can connect compatible sensors without soldering. It matters because your controller or adapter also needs Qwiic, or you will need a cable or breakout to wire it up.
- RF
- RF means radio frequency, referring to signals used for wireless communication and other high-frequency electronics. A low-noise, stable power supply is important for RF circuits because power noise can affect signal quality and measurements.
- RTK
- Real-Time Kinematic positioning is a GNSS technique that uses correction data from a base station to greatly improve location accuracy. It matters if you need centimetre-level positioning for robotics, mapping, surveying, or tracking rather than ordinary metre-level GPS accuracy.
- RX
- RX means receive, usually showing data being received by the board. An RX indicator LED can help with troubleshooting USB or serial communication.
- Shield
- An add-on board that plugs into a main controller board to give it extra features such as sensing, motor control or communication. Knowing a product supports shields helps you judge whether it can connect neatly into an existing maker-board setup.
- SMA
- SMA is a small threaded coaxial (RF) connector widely used to attach antennas and other radio-frequency cables. A device with SMA antenna ports needs antennas or pigtails with matching SMA connectors, or a suitable adapter, to connect to them.
- SRAM
- Fast temporary memory used by a processor while a program is running. More SRAM helps with projects that handle larger data buffers, networking, displays, or more complex code.
- Thread
- A low-power wireless mesh networking standard designed for smart home and IoT devices. It matters because Thread devices can relay messages through each other, helping build reliable networks for sensors and controllers.
- TTL serial
- A simple serial data connection that uses microcontroller logic-level voltages (typically 3.3 V or 5 V) rather than the higher, inverted voltages of computer RS-232. When a device lists TTL serial, it can usually wire straight to a microcontroller's UART pins or to a USB-to-TTL serial adapter, but it needs a level converter before connecting to a true RS-232 port.
- TX
- TX means transmit, usually showing data being sent from the board. A TX indicator LED can help you see when the board is communicating or uploading code.
- UBX binary protocol
- UBX is u-blox’s binary communication protocol for sending configuration commands and receiving detailed navigation data. It matters when you want faster, more compact, or more complete data than standard text-based GPS messages can provide.
- ZED-F9P
- A u-blox GNSS receiver module designed for high-precision positioning, including RTK rover and base-station use. The exact module matters because it determines the supported satellite bands, update rates, correction formats and achievable accuracy.
Find this product in
RTK Express Schematic
Schematic · 221.1 KB · Click any page to view full size
TOP106 GNSS L1/L2 Antenna Datasheet
Datasheet · 924.7 KB · Click any page to view full size
Supplier page — sparkfun.com
Supplier Description · 803.7 KB · Click any page to view full size
Source Code
Open-source libraries, firmware & example projects for this product
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65a503a
20 days ago
· 2.8k commits
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9a1a280
over 1 year ago
· 55 commits
- .github Update issue templates over 4 years ago
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