U-blox ZED-F9 GNSS Module Controller Library

A lightweight C++ library for communicating with u-blox ZED-F9 series GNSS modules on Linux systems, designed for headless environments where u-center is not available.

Features

• Serial communication with u-blox GNSS modules
• UBX protocol message formatting and parsing
• Checksum calculation and validation
• ACK/NAK response handling
• Extensible message support system
• Header-only implementation for easy integration

Supported Messages

Currently implemented messages:

• UBX-MON-VER - Retrieves software and hardware version information

Prerequisites

• Linux-based operating system
• C++ compatible compiler
• Serial port access to u-blox device (typically /dev/ttyACM0)
• Proper permissions to access serial devices

Installation

1. Clone the repository:

git clone <repository-url>
cd ublox-controller

2. Include the header in your project:

#include "lib/ublox_controller.h"

3. Compile your application with the necessary flags:

g++ your_application.cpp -o your_application

Basic Usage

#include "lib/ublox_controller.h"

int main() {
    UbloxController controller("/dev/ttyACM0");
    
    if (!controller.openSerialPort()) {
        std::cerr << "Failed to open serial port" << std::endl;
        return 1;
    }
    
    // Send a message with empty payload (poll request)
    if (controller.sendUBXMessage(0x0A, 0x04, {})) {
        std::vector<uint8_t> response;
        if (controller.readUBXMessage(0x0A, 0x04, response)) {
            // Process response
        }
    }
    
    controller.closeSerialPort();
    return 0;
}

Message Implementation Format

To add support for new UBX messages, create a new .cpp file following this format:

File Naming Convention

Use the format: UBX-{CLASS}-{ID}.cpp (e.g., UBX-CFG-PRT.cpp)

Implementation Template

#include <iostream>

#include "lib/ublox_controller.h"

// UBX message definitions
#define UBX_CLS_EXAMPLE 0xXX  // Replace with actual class
#define UBX_ID_EXAMPLE 0xXX   // Replace with actual ID

using namespace std;

int main() 
{
    UbloxController controller;
    if (!controller.openSerialPort()) {
        cout << "Failed to open serial port" << endl;
        return 1;
    }
    
    // Create payload if needed, or use empty vector for poll requests
    vector<uint8_t> payload = {
        // Add payload bytes here
    };
    
    cout << "Sending UBX message..." << endl;
    if (!controller.sendUBXMessage(UBX_CLS_EXAMPLE, UBX_ID_EXAMPLE, payload)) {
        cerr << "Failed to send message." << endl;
        return 1;
    }

    // Wait for ACK/NAK if required
    int ackResult = controller.waitForAck(UBX_CLS_EXAMPLE, UBX_ID_EXAMPLE);
    if (ackResult != ACK) {
        cerr << "Message not acknowledged" << endl;
        return 1;
    }

    // Read response if expected
    vector<uint8_t> response;
    if (controller.readUBXMessage(UBX_CLS_EXAMPLE, UBX_ID_EXAMPLE, response)) {
        // Parse response according to message specification
        cout << "Response received successfully" << endl;
        
        // Add your parsing logic here
    }

    controller.closeSerialPort();
    return 0; 
}

Contributing New Messages

I welcome contributions to expand the library's message support! To add a new UBX message:

1. Study the message specification in the u-blox protocol documentation
2. Create a new .cpp file following the naming convention above
3. Implement the message using the provided template
4. Test thoroughly with your hardware
5. Submit a pull request with your implementation

Required Information for New Messages

• UBX class and message ID
• Payload structure (if any)
• Response format (if any)
• Any special handling requirements

Error Handling

The library provides several error codes:

• ACK (1): Message acknowledged
• NAK (0): Message not acknowledged
• ERROR_TIMEOUT (-1): Response timeout
• ERROR_CHECKSUM (-2): Checksum validation failed
• SOCK_NOT_OPEN (-3): Serial port not open

Serial Configuration

The library configures the serial port with these settings:

• Baud rate: 38400 (default for ZED-F9 modules)
• 8 data bits, no parity, 1 stop bit
• No flow control
• Raw mode (non-canonical)

Resources

• u-blox ZED-F9R Protocol Specification
• u-center Software (for testing and validation)

Support

For issues and questions:

1. Check the u-blox protocol documentation
2. Review existing message implementations
3. Create an issue in the GitHub repository

Disclaimer

This library is not affiliated with or endorsed by u-blox. Always verify message formats and behaviors against the official u-blox protocol documentation.