CellularPi

A modern Qt6-based cellular modem testing interface with SMS capabilities and REST API testing functionality. This application provides a user-friendly GUI for controlling cellular modems and testing internet connectivity on Linux systems.

Blogs

1. The Implementation Chronicles: A7670E USB Modem: Part 1
2. Driver Support for A7670E: Kernel Module Implementation: Part 2
3. Testing A7670E Modem Features with CellularPi: Part 3

Features

SMS Management

• Send SMS messages through cellular modem
• Real-time delivery status updates
• Message length tracking and validation
• Queue management for multiple messages
• Automatic retry mechanism
• Error handling and user feedback

Internet Connectivity

• REST API testing interface
• Support for common HTTP methods (GET, POST, PUT, DELETE)
• JSON request/response visualization
• SSL/TLS support
• Built-in demo API integration

Requirements

System Requirements

• Linux-based operating system
• ModemManager service installed and running
• Qt 6.7.0 or later
• CMake 3.16 or later
• C++17 compliant compiler

Qt Modules Required

• Qt Core
• Qt Quick
• Qt Network
• Qt DBus
• Qt Concurrent

Project Structure

CellularPi/
├── CMakeLists.txt              # Main CMake configuration
├── Modem/                      # Modem management module
│   ├── CMakeLists.txt
│   ├── modem.h/cpp            # Core modem functionality
│   └── modemdbusmanager.h/cpp # D-Bus communication
├── REST/                       # REST client module
│   ├── CMakeLists.txt
│   └── restclient.h/cpp       # REST API functionality
├── Qml/                       # QML interface files
│   ├── CMakeLists.txt
│   └── Main.qml              # Main application window
└── README.md

Cross-Compilation

Option 1: Native Development on Raspberry Pi

Follow the comprehensive setup guide at QTonRaspberryPi to properly configure your Raspberry Pi for Qt development. This includes:

• Installing required packages
• Setting up Qt development tools
• Configuring the build environment

Option 2: Cross-compilation for ARM64 (Recommended)

For faster development and build times, we recommend using cross-compilation. Here's how to set it up:

1. Clone the development environment repository:

git clone https://github.com/learnqtkenya/QTonRaspberryPi.git
cd QTonRaspberryPi

2. Clone CellularPi into the project directory:

rm -rf project && git clone https://github.com/learnqtkenya/CellularPi.git project

3. Create a build script (build.sh):

#!/bin/bash

# Function to run a command and print a warning if it fails
run_command() {
    "$@"
    if [ $? -ne 0 ]; then
        echo "Warning: Command failed: $@"
    fi
}

# Run each command using the run_command function
run_command rm -rf appCellularPi
run_command docker rm tmpbuild
run_command docker build -t qtcrossbuild . 
run_command docker create --name tmpbuild qtcrossbuild
run_command docker cp tmpbuild:/build/project/appCellularPi ./appCellularPi
echo "Build script completed."

4. Make the script executable and run it:

chmod +x build.sh
./build.sh

This will create a Docker container with the necessary cross-compilation environment, build CellularPi, and copy the resulting binary to your host machine.

5. Deploy to Raspberry Pi:

scp appCellularPi pi@raspberrypi:/home/pi/

Build Verification

After deploying to the Raspberry Pi, verify the build:

# On the Raspberry Pi
chmod +x appCellularPi
./appCellularPi 

User Interface

• Modern, responsive design
• Universal theme support
• Dynamic scaling for different screen sizes
• Tabbed interface for organized functionality
• Real-time status updates

Usage

SMS Functionality

1. Launch the application
2. Enter the recipient's phone number in international format (e.g., +1234567890)
3. Type your message (160 characters max)
4. Click "Send SMS" to transmit

REST API Testing

1. Switch to the "Internet" tab
2. Select an endpoint from the dropdown or enter a custom one
3. Use the GET/POST buttons to make requests
4. View formatted responses in the response area
5. Test custom APIs by modifying the base URL

Technical Details

Modem Integration

• Uses ModemManager's D-Bus interface
• Asynchronous message handling
• Queued message processing
• Automatic retry mechanism for failed messages

REST Client Features

• Based on Qt 6.7's new REST client features
• Support for modern REST APIs
• JSON parsing and formatting
• Error handling and retry logic
• SSL/TLS certificate handling

Architecture

• Modular design with separate components for modem and REST functionality
• QML for the user interface
• C++ for core functionality
• Event-driven communication between components

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Submit a pull request

Please follow our coding style and include appropriate tests.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Qt Company for Qt 6.7 and the REST client features
• ModemManager team for the D-Bus interface
• JSONPlaceholder for the demo API