Usage Guide

RTK Rover refers to the use of the LG290P module as a mobile station, connecting and receiving RTCM data streams from services like Qianxun Positioning (China mainland) or other reference base station service provider to achieve high-precision centimeter-level positioning.
RTK Base refers to using the LG290P as a base station to establish a CORS (Continuous Operational Reference System), providing RTCM data streams to other devices, thereby enabling real-time centimeter-level positioning for those devices.

Windows

This section is the introduction to quick setup and use of LG290P series modules using QGNSS software on Windows PCs. For detailed instructions on using QGNSS software, please refer to the Quectel_QGNSS_User_Guide_V3.2.pdf file from QGNSS_2.2.zip

Install CH343 Driver

Download and double-click to install CH343 Windows VCP driver

Implement RTK Mobile Station Positioning

• Download and open QGSS tool, 1️⃣click NTRIP client, 2️⃣click view, ️3️⃣select Data View to open, 4️⃣open the satellite signal bar graph interface, 5️⃣configure the following Addressh and Port parameters to the corresponding location:

 Address:    ntrip.geodetic.gov.hk
 Port:                        2101
 Mount Point:               HKCL_32
 Username:                    Leave blank
 Password:                    Leave blank

6️⃣click Update NTRIP Source Table, 7️⃣ select HKCL_32 node, 8️⃣turn on ON, the button turns green, and the communication with the base station is successful. NTRIP Client prints the following information:

Received (14)bytes from server : 
ICY 200 OK

Wait for 2-15 minutes until the latitude, longitude, and Float RTK prompts appear in the Data View window on the right to achieve RTK positioning, 9️⃣Open the deviation chart to see the positioning accuracy 

RTK Base RTK Caster RTK Rover

• Before setting up the base station module, first understand that NTRIP (Networked Transport of RTCM via Internet) is an acronym for transmitting RTK differential data over the Internet. This allows for the expansion of RTK networks with an unlimited number of bases and mobile stations. A network with multiple NTRIP devices is called an NTRIP network. There are three roles in an NTRIP network: NTRIP Caster, which is a server responsible for receiving and sending GNSS differential data. It collects RTK correction data (i.e., RTCM data) from one or more base stations and distributes it to RTK mobile stations. Emlid Caster and rtk2go, etc., are cloud-based public Casters that can transmit RTCM data by uploading it to these relay stations, eliminating the cumbersome steps of setting up a Caster. Below, we will test by setting up the Emlid Caster public Caster as an example.

 Configure the My mount points from the above image to the base station, and configure the My rovers parameters to the mobile station

• Open the QGNSS tool, 2️⃣enter the parameters obtained from the Emlid Caster in the NTIRP Server window

 ADDRESS:              164.90.243.252
 PORT:                           2101
 MOUNT POINT:                MP24981d
 PASSWORD:                     62XXXX

• Then check "Start", and after successfully connecting to the server, print

Connect to caster success 
ICY 200 OK; 

#Configure module working mode to base station mode
$PQTMCFGRCVRMODE,W,2*29

#Command executed successfully
$PQTMCFGRCVRMODE,OK*64

#Save configuration
$PQTMSAVEPAR*5A

#Command executed successfully
$PQTMSAVEPAR,OK*72

#Restart the module (either by sending the relevant command or by pin reboot of the hardware RESET_N, using the command to restart here)
$PQTMSRR*4B

#Waiting for the module to power on
#Configure the base station Survey-in mode, with 60 positioning (convergence) times, and a 3D location accuracy threshold of 15.0 meters)
$PQTMCFGSVIN,W,1,60,15.0,0,0,0*3E

#Command executed successfully
$PQTMCFGSVIN,OK*70

#Configure PQTMSVINSTATUS through PQTMCFGMSGRATE to output once per positioning to view Survey-in status (this step is optional)
$PQTMCFGMSGRATE,W,PQTMSVINSTATUS,1,1*58

#Command executed successfully
$PQTMCFGMSGRATE,OK*29

#Save configuration
$PQTMSAVEPAR*5A

#Command executed successfully
$PQTMSAVEPAR,OK*72

#Restart the module (either by sending the relevant command or by pin reboot of the hardware RESET_N, using the command to restart here)
$PQTMSRR*4B

#Output the mean base station convergence ECEF coordinates via RTCM3-1005 (this statement is output by default when the module is in base station mode)
D3 00 13 3E D1 22 03 3B 54 97 DA 6F 8C 99 B2 AF 40 06 4C FC 1A 4B 1E 7D F1

#View the convergence mean of the ECEF coordinates of the base station from the start of the convergence to the completion of the convergence via PQTMSVINSTATUS (this step is optional and it is recommended to turn off the output of the statement after the convergence is complete)
$PQTMSVINSTATUS,1,291264000,1,,11,1,60,-2005560.2218,5411825.5447,2706139.7061,1.8691*0C
$PQTMSVINSTATUS,1,291265000,1,,11,2,60,-2005560.1264,5411824.9421,2706139.6738,4.9992*09
$PQTMSVINSTATUS,1,291266000,1,,11,3,60,-2005560.1137,5411824.5510,2706139.6722,4.3119*0B
$PQTMSVINSTATUS,1,291267000,1,,11,4,60,-2005560.2000,5411824.9447,2706140.0627,1.3000*04
…
$PQTMSVINSTATUS,1,291320000,1,,11,57,60,-2005559.8625,5411823.2315,2706139.4103,1.7206*36
$PQTMSVINSTATUS,1,291321000,1,,11,58,60,-2005559.8577,5411823.2160,2706139.4067,1.6716*3A
$PQTMSVINSTATUS,1,291322000,1,,11,59,60,-2005559.8530,5411823.2016,2706139.4032,1.7830*31
$PQTMSVINSTATUS,1,291323000,2,,11,60,60,-2005559.8481,5411823.1873,2706139.3995,1.8075*3F
$PQTMSVINSTATUS,1,291324000,2,,11,60,60,-2005559.8481,5411823.1873,2706139.3995,1.8075*38
$PQTMSVINSTATUS,1,291325000,2,,11,60,60,-2005559.8481,5411823.1873,2706139.3995,1.8075*39

#After convergence is completed, close PQTMSVINSTATUS via PQTMCFGMSGRATE
$PQTMCFGMSGRATE,W,PQTMSVINSTATUS,0,1*59

#Command executed successfully
$PQTMCFGMSGRATE,OK*29

#Save configuration
$PQTMSAVEPAR*5A

#Command executed successfully
$PQTMSAVEPAR,OK*72

#Restart the module (either by sending the relevant command or by pin reboot of the hardware RESET_N, using the command to restart here)
$PQTMSRR*4B

• Open Data View at the same time to check the base station convergence3️⃣. After successful convergence, you will obtain the base station's latitude and longitude. After about 12 hours, you can get relatively accurate base station coordinates
• This data will be transmitted to the mobile station through the caster relay station, so the corresponding parameters of the caster also need to be configured for the mobile station

 ADDRESS:              164.90.243.252
 PORT:                           2101
 MOUNT POINT:                MP24981d
 USERNAME                      u92454
 PASSWORD:                     35XXXX

• Wait for several hours until both the base station and mobile station are stable, then Float RTK appears and RTK positioning is successful

Raspberry Pi

This section is an example of testing instructions using a Raspberry Pi and an LG290P HAT; in fact, Linux operating systems are largely similar, and they can also be adapted to common Linux series motherboards like Jetson and RDK. Tested under an open, clear ☀️ sky, the more open and clearer the weather ☀️, the more accurate the RTK positioning

Environment Setup

• By connecting via USB to a Linux host, the latest version of the Raspberry Pi system already has the CH343 driver built-in, and it loads the default serial port as ttyACM0

• Download and run a Python3 program in the Raspberry Pi terminal shell interface. Enter the generated IP + port number in the browser to get the Ntrip Client window interface. Enter relevant parameters for Hi-Target, Chihiro, Trimble, or self-built base stations, etc. Here, we test with Hi-Target's CORS account as an example:

wget https://files.waveshare.com/wiki/LG290P-GNSS-RTK-Module/Demo/LG290P-GNSS-RTK-Module-Demo.zip
sudo unzip LG290P-GNSS-RTK-Module-Demo.zip
cd LG290P-GNSS-RTK-Module-Demo/Raspberry_Pi/Python/RTK_Rover/
sudo python3 web_rtk.py

• Please copy the IP address and port number displayed by the program, then paste it into the address bar of a Raspberry Pi or a computer on the same local network：

http://192.168.10.10:5000

• Configure the corresponding serial port number, the default is ttyACM0, copy the Hi-Target RTK parameters to the configuration box, click Start RTK

RTK BASE

Windows systems can use STRSVR to upload base station information to the server. For Linux systems, you can refer to the following steps to install the rtkbase tool to upload the server. Here, the Raspberry Pi is used as an example for testing. The testing steps for Linux hosts such as Jetson are similar, and the demo can be shared:

• Copy the following command lines to the Raspberry Pi terminal

https://github.com/Stefal/rtkbase
git clone https://github.com/Stefal/rtkbase.git
cd rtkbase/tools
sudo ./install.sh --all release

sudo apt-get update --allow-releaseinfo-change

sudo apt-get update --allow-releaseinfo-change --allow-unauthenticated

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 0E98404D386FA1D9 6ED0E7B82643E131

• After correctly installing the tool on the web page, the following prompt will appear:

• Then directly open the browser and access the local address (Raspberry Pi IP) (here it is 192.168.10.87), and on the Raspberry Pi side, you need to open the corresponding button to enable the server to be online

ESP32 Test

• LG290P GNSS RTK Module is connected to ESP32 via UART, and the antenna is also connected. Place the module in the open outdoors, or at least place the positioning antenna receiver under the visible sky for testing, the pin connection diagram is as follows:

• Take the ESP32-S3 test as an example, set up an ESP32-S3 environment, modify the following parameters in the demo:

//Connect ESP to WiFi to enable access to base station server data
const char* ssid         = "mate60";   //Hotspot SSID
const char* wifiPassword = "131433";  //Corresponding password

// ---------- NTRIP(Here is an example of Hi-Target CORS, modify the following parameters accordingly)----------
const char* ntripHost  = "120.253.226.97";
const int   ntripPort  = 8001;
const char* mountpoint = "RTCM33_GRCEJ";
const char* ntripUser  = "cvmh11286";
const char* ntripPass  = "fyxxx";

• Compile and flash the GetGPS-RTK.ino program to the esp32, and the indoor test results are shown in the figure below:

• It is not possible to achieve GNSS and RTK positioning indoors. Bring a laptop to the visible sky and test the results as shown in the following figure. The laptop does not have Arduino environment installed. Here, we use SSCOM to demonstrate:

Raspberry Pi Pico Test

• If you need to use RTK functionality, use the Raspberry Pi Pico 2 W series, and implement RTK positioning similar to ESP32 steps. Here, using the Raspberry Pi Pico 2 as an example, we test standard GNSS positioning. GNSS positioning is also the most basic function of the LG290P GNSS RTK Module. The wiring diagram is as follows:

• Opening and running demos in Thonny allows you to obtain the original GNSS messages, as shown in the figure below:

Resources

Documents

• Schematic

Engineering Drawings

• 3D Drawings

Demos

• Demo

Software

• Windows RTK debugging tools:

QGNSS_V2.2 or QGNSS_V2.1

• CH343 driver
• SSCOM debugging assistant

Datasheets

• LG290P GNSS protocol specifications
• NMEA0183

FAQ

Support

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