Gravity: GNSS-RTK High Precision Positioning Kit-US

1. Getting StartedNew

Starting with the basics of GPS/GNSS and the principles of RTK centimeter-level positioning, this book gradually analyzes the RTK data link and the NMEA 0183 GGA statement fields.

2. Example Code for Arduino-Reading Data via UARTNew

Read latitude, longitude, and positioning status from the GNSS-RTK kit using the UART protocol with Arduino IDE.

3. Example Code for Arduino-Reading NMEA Data via I2C Protocol

Read NMEA data from the GNSS-RTK kit using the I2C protocol with Arduino IDE.

4. Example Code for Raspberry Pi-UART Tutorial

Read GNSS data from the GNSS-RTK kit using the UART protocol with Raspberry Pi.

5. Example Code for Raspberry Pi-I2C TutorialNew

Read GNSS data from the GNSS-RTK kit using the I2C protocol with Raspberry Pi.

Reference

文档提供GNSS Arduino API Reference，涵盖getUTC、getDate、getLat、getLon、getAlt、getNumSatUsed等定位接口及setModule、setModuleBaud、setCallback等模块控制函数，并附GNSS Protocol Specification

1. Specification

1.1 Base Station

Parameter	Details
Power Supply	Type-C Terminal: 5~10V
GNSS Antenna Interface	SMA
Reception Bands	GPS/QZSS: L1 C/A, L5 GLONASS: L1 Galileo: E1, E5a BDS: B1I, B2a
Default Constellations	GPS + GLONASS + Galileo + BDS + QZSS
Concurrent Constellations	4 + QGNSS
Function	Base station
Sensitivity	Acquisition: -147 dBm Tracking: -165 dBm Reacquisition: -159 dBm
Dynamic Performance	Max Altitude: 10000 m Max Velocity: 500 m/s Max Acceleration: 4g
Raw Data Update Rate	1 Hz
Protocol	NMEA 0183 / RTCM 3.x

1.2 Mobile Station (RTK Mobile)

Parameter	Details
Operating Voltage	3.3V~5V
Output Signal	I2C/UART
Antenna Interface	SMA
Reception Bands	GPS/QZSS: L1 C/A, L5 GLONASS: L1 Galileo: E1, E5a BDS: B1I, B2a
Default Constellations	GPS + GLONASS + Galileo + BDS + QZSS
Concurrent Constellations	4 + QGNSS
SBAS	WAAS, EGNOS, MSAS, GAGAN
Function	RTK
Horizontal Positioning Accuracy	Autonomous: 1 m RTK: 5 cm + 1 ppm
Velocity Accuracy	0.03 m/s
1PPS Accuracy	20 ns
RTK Convergence Time	<10 s
Sensitivity	Acquisition: -145 dBm Tracking: -165 dBm Reacquisition: -157 dBm
Dynamic Performance	Max Altitude: 10000 m Max Velocity: 500 m/s Max Acceleration: 4g
Navigation Update Rate(RTK)	1 Hz
Raw Data Update Rate(GNSS)	1 Hz
Protocol	NMEA 0183 / RTCM 3.x
LoRa Parameters	RF Chip Semtech: LLCC68 Operating Frequency: 915MHz Modulation: LoRa Spread Spectrum Max Transmit Power: 22dBm Receiver Sensitivity: -129dBm
Weight	700g

2. Appearance and Interface

2.1 Mobile Station

Mobile

Name	Description
RTK	RTK status LED: Blinks at 1Hz for state 5 (positioning); Steady for state 4; Off for other states.
PWR	Power indicator
UART I2C	Toggle switch for UART/I2C communication interface
Gravity I2C&UART	Gravity interface for data output

2.2 Base Station

Base Station

Name	Description
Type-C	Type-C power interface
PWR	Power indicator
PWR IN	External terminal power (5~10V)

3. Product Features

LoRa Data Transmission: Utilizes LoRa wireless technology for stable, long-range, and low-power communication of RTCM correction data between the base station and rover(s).
User-Friendly: Designed for ease of use with a pre-configured data link, enabling rapid setup and operation right out of the box.
Low Cost of Use: Provides an accessible entry point into high-precision positioning technology, minimizing initial investment and complexity.
Centimeter-Level Accuracy in Open Areas: Achieves high-precision centimeter-level positioning under optimal open-sky conditions.
Single Base Station Supports Multiple Mobile: One base station can broadcast correction data to several Mobile units simultaneously, improving efficiency and scalability.