ArduSimple simpleRTK2B

The ArduSimple simpleRTK2B is the most popular low-cost RTK board, built around the u-blox ZED-F9P multi-band GNSS module. It tracks GPS, GLONASS, Galileo, and BeiDou on L1/L2 frequencies and delivers centimeter-level accuracy with RTK corrections. The newer simpleRTK3B uses the u-blox ZED-F9R with built-in IMU for dead reckoning. Both boards are compatible with the ArduSimple RTK Handheld kit and the RTK Calibrated Surveyor kit. This guide covers two setup methods: Bluetooth to phone (fieldwork) and direct USB to PC (bench testing).

Requirements

• ArduSimple simpleRTK2B or simpleRTK3B board with GNSS antenna and clear sky view

• Method A: Smartphone with Bluetooth and the Lefebure NTRIP Client or SW Maps app (Android)

• Method B: Windows PC with USB cable and u-blox u-center installed

• RTKdata.com account with active RTK credentials (username starting with rtk)

• ArduSimple Bluetooth module (XBee socket) if using Method A

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Method A: Bluetooth to Phone (Lefebure or SW Maps)

This is the recommended method for field use. Your phone runs the NTRIP client and forwards RTCM corrections to the F9P over Bluetooth.

1

Prepare the board

1. Insert the ArduSimple Bluetooth module into the XBee socket on the simpleRTK2B.

2. Connect your GNSS antenna to the board and place it with a clear sky view.

3. Power the board via USB or battery. The green power LED should be solid.

4. Confirm UART2 is configured for RTCM input at the correct baud rate. The default is 38400 for UART2. If you have changed it, use 115200 for best performance.

If UART2 is not configured to accept RTCM input, corrections from the phone will be ignored. In u-center, go to UBX-CFG-PRT and enable RTCM3 on UART2 input.

2

Pair Bluetooth on your phone

1. On your Android phone, go to Settings > Bluetooth and scan for devices.

2. Pair with the ArduSimple module (typically named RTK_GNSS or ArduSimple).

3. Note the paired device name for the next step.

3

Configure the NTRIP client app

Open Lefebure NTRIP Client or SW Maps and create an NTRIP profile with these settings:

North America

• Host (domain): rtk.rtkdata.com

• Host (IP fallback): 13.56.117.10

• Port: 2101

• Username / Password: From RTK Credentials in the internal dashboard (not website login)

• Mountpoint (ALL CAPS): AUTO (recommended) — or AUTO_WGS84, AUTO_ITRF2020, AUTO_ITRF2014

Europe

Australia

• Send NMEA GGA to Server: ON (critical — without GGA, RTKdata cannot compute corrections)

• Receiver connection: Select your paired ArduSimple Bluetooth device.

4

Connect and verify RTK Fix

1. Tap Connect in the NTRIP client. The app streams RTCM corrections over Bluetooth to the F9P.

2. Monitor the solution status: 3D Fix > DGPS > Float > Fix.

3. Once the board achieves RTK Fix, accuracy drops to 1-2 cm. Convergence typically takes 30-90 seconds.

4. The No RTK LED on the simpleRTK2B should turn off when Fix is achieved.

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Method B: USB to PC with u-center

This method is ideal for bench testing, firmware updates, and initial board configuration.

1

Connect the board to your PC

1. Plug the simpleRTK2B into your PC via USB. Windows should install the driver automatically (u-blox or FTDI).

2. Open u-center and select the correct COM port under Receiver > Connection.

3. Set the baud rate to 115200 (or 38400 if default).

4. Confirm you see satellite data in the satellite view panel.

2

Enable the u-center NTRIP client

1. Go to Receiver > NTRIP Client Settings.

2. Enter the connection details for your region:

North America

• Address: rtk.rtkdata.com

• Port: 2101

• Username / Password: Your RTK credentials

• Mountpoint: AUTO

Europe

Australia

1. Enable Send GGA and set the interval to 5 seconds.

2. Click OK to connect.

If GGA is not being sent, you will see "0 GGA sessions" in the RTKdata dashboard and the caster will reject the connection. Always verify GGA is enabled.

3

Verify RTK Fix in u-center

1. Open the Data View panel (View > Data View). The Fix Mode field will show the current solution.

2. Watch the progression: 3D > DGNSS > Float > Fix.

3. The horizontal accuracy estimate (hAcc) should drop below 0.02 m at Fix.

4. The u-center map view will show your position converging to a stable point.

Vertical reference (heights)

Heights from RTKdata.com are ellipsoidal, not orthometric (mean sea level). Apply a geoid model in your GIS or surveying software if MSL heights are required.

Troubleshooting

Problem	Cause	Fix
No GGA sent (0 GGA sessions on dashboard)	GGA output disabled in app or u-center	Enable Send NMEA GGA in Lefebure / SW Maps, or enable Send GGA in u-center NTRIP settings.
Wrong COM port in u-center	Multiple USB devices connected	Open Device Manager and confirm which COM port is assigned to the u-blox or FTDI device.
UART2 not receiving corrections	RTCM input not enabled on UART2	In u-center, navigate to UBX-CFG-PRT > UART2 and enable RTCM3 under Protocol In.
Mountpoint error	Typed in lowercase	Enter AUTO in ALL CAPS. Do not browse the mountpoint table.
Bluetooth pairs but no data flows	Baud rate mismatch	Ensure the Bluetooth module and UART2 are both set to the same baud rate (38400 or 115200).
Slow convergence or no Fix	Outdated firmware	Update the ZED-F9P firmware via u-center (Tools > Firmware Update). Use the latest HPG firmware from u-blox.

Tips and tricks

• Update your F9P firmware first. Newer HPG firmware versions significantly improve Fix time and multi-constellation support. Download from the u-blox website.

• Method A is best for fieldwork and pairs well with the ArduSimple RTK Handheld kit. Method B is best for initial configuration and bench testing.

• Set UART2 to 115200 baud for faster RTCM throughput, especially when using multiple constellation corrections.

• The simpleRTK3B (F9R) adds dead reckoning via its built-in IMU. The NTRIP setup is identical to the simpleRTK2B.

• For the RTK Calibrated Surveyor kit, the board comes pre-configured with correct UART settings. Skip the UART2 configuration step.

• Log raw data to the onboard microSD (if equipped) for PPK post-processing as a fallback when NTRIP connectivity is intermittent.