How to Use Here4 Blue Multiband RTK GNSS: Examples, Pinouts, and Specs

The Here4 Blue Multiband RTK GNSS (Manufacturer Part ID: CP-06279) is a high-precision Global Navigation Satellite System (GNSS) receiver developed by CubePilot. It supports multiple frequency bands and Real-Time Kinematic (RTK) technology, enabling centimeter-level positioning accuracy. This component is ideal for applications requiring precise navigation and positioning, such as surveying, mapping, autonomous vehicles, and robotics.

• Surveying and geospatial mapping
• Autonomous vehicle navigation
• Precision agriculture
• Drone flight control systems
• Robotics requiring high-accuracy localization

The Here4 Blue Multiband RTK GNSS features a standard connector with the following pinout:

1. Power Supply: Connect the VCC pin to a stable 5V DC power source and the GND pin to ground.
2. Communication Interface: Choose one of the supported communication interfaces (UART, I2C, or CAN):
   • For UART, connect the TX and RX pins to the corresponding UART pins on your microcontroller.
   • For I2C, connect the I2C_SCL and I2C_SDA pins to the I2C bus of your microcontroller.
   • For CAN, connect the CAN_H and CAN_L pins to the CAN bus.
3. Antenna Connection: Attach a compatible GNSS antenna to the SMA connector for optimal signal reception.
4. RTK Setup: If using RTK, configure the base station and rover settings as per your application requirements.

• Antenna Placement: Ensure the GNSS antenna is placed in an open area with a clear view of the sky for optimal satellite reception.
• Power Supply: Use a stable and noise-free 5V power source to avoid interference with GNSS signals.
• RTK Configuration: For RTK functionality, ensure the base station and rover are properly synchronized and within communication range.
• Firmware Updates: Regularly check for firmware updates from CubePilot to ensure compatibility and performance improvements.

Below is an example of how to interface the Here4 Blue Multiband RTK GNSS with an Arduino UNO using UART:

#include <SoftwareSerial.h>

// Define RX and TX pins for SoftwareSerial
SoftwareSerial GNSSSerial(10, 11); // RX = pin 10, TX = pin 11

void setup() {
  // Initialize serial communication with GNSS module
  GNSSSerial.begin(9600); // Set baud rate to 9600 (adjust if needed)
  
  // Initialize serial communication with PC for debugging
  Serial.begin(9600);
  Serial.println("Here4 Blue Multiband RTK GNSS Test");
}

void loop() {
  // Check if data is available from the GNSS module
  if (GNSSSerial.available()) {
    // Read data from GNSS module
    String gnssData = GNSSSerial.readString();
    
    // Print GNSS data to the Serial Monitor
    Serial.println(gnssData);
  }
}

Note: Adjust the baud rate in the code to match the default baud rate of the GNSS module.

1. No GNSS Signal Detected:

   • Ensure the antenna is properly connected and placed in an open area with a clear view of the sky.
   • Verify that the power supply is stable and noise-free.

2. RTK Not Working:

   • Check the base station configuration and ensure it is transmitting correction data.
   • Verify that the rover is within the communication range of the base station.

3. No Data Output:

   • Confirm that the communication interface (UART, I2C, or CAN) is correctly configured.
   • Check the wiring and ensure the correct pins are connected.

4. Intermittent Signal Loss:

   • Avoid placing the GNSS module near sources of electromagnetic interference (e.g., motors, power lines).
   • Use a high-quality GNSS antenna and cables.

Q: Can the Here4 Blue Multiband RTK GNSS be used indoors?
A: GNSS signals are weak indoors, so the module is best used outdoors. For indoor applications, consider using a GNSS repeater or alternative positioning systems.

Q: What is the maximum range for RTK communication?
A: The range depends on the communication method used (e.g., radio, Wi-Fi). Typically, RTK communication works within a few kilometers when using a radio link.

Q: How do I update the firmware?
A: Firmware updates can be downloaded from CubePilot's official website. Follow the provided instructions to update the module via the appropriate interface.

Q: Is the module compatible with Pixhawk flight controllers?
A: Yes, the Here4 Blue Multiband RTK GNSS is fully compatible with Pixhawk and other CubePilot flight controllers.