Add Android MQTT app option for LifeTrac v25 remote control

[Copilot]

Implements a comprehensive Android mobile app solution for wireless control of LifeTrac v25 using MQTT over WiFi. This provides a modern smartphone/tablet alternative to the existing ESP32 hardware remote control.

Overview

The Android app is built using Kodular.io (MIT App Inventor) with the UrsPahoMqttClient component, offering dual virtual joystick control that mirrors the functionality of the ESP32 remote. The implementation integrates seamlessly with the existing LifeTrac v25 MQTT infrastructure without requiring any changes to the Arduino Opta controller code.

Key Features

Mobile Control Interface:

• Dual virtual joysticks for tank steering (left) and hydraulic functions (right)
• Real-time MQTT communication at 20Hz frequency matching the ESP32 remote
• Emergency stop button with immediate safety response
• Visual connection status indicators for WiFi and MQTT
• Configurable MQTT broker settings with validation

Safety Integration:

• Compatible with existing 1-second communication timeout
• Emergency stop sends immediate zero commands to all systems
• Connection monitoring with automatic reconnection
• Fail-safe operation matching hardware remote behavior

Technical Implementation

The app sends JSON control messages to the existing lifetrac/v25/control MQTT topic:

{
  "left_x": -50,    // Tank steering turn (-100 to +100)
  "left_y": 75,     // Forward/backward movement (-100 to +100) 
  "right_x": 0,     // Bucket control (-100 to +100)
  "right_y": -25,   // Arms control (-100 to +100)
  "timestamp": 12345
}

This matches the exact format used by the ESP32 remote, ensuring complete compatibility with the existing Arduino Opta controller logic.

Files Added

Documentation & Guides:

• android_mqtt_app/README.md - Complete user manual with installation and troubleshooting
• android_mqtt_app/QUICK_START.md - 5-minute setup guide
• android_mqtt_app/KODULAR_BUILD_INSTRUCTIONS.md - Detailed app development guide with block programming
• android_mqtt_app/LifeTracV25_Remote_Template.txt - Project structure template
• android_mqtt_app/ANDROID_PERMISSIONS.md - Device requirements and permissions
• android_mqtt_app/F-DROID_SUBMISSION_GUIDE.md - Complete guide for submitting to F-Droid open-source app store

Development Tools:

• android_mqtt_app/mqtt_test_listener.py - Python script for monitoring MQTT messages with visual feedback
• android_mqtt_app/simulate_android_app.py - Keyboard-controlled simulator for testing without building the app
• android_mqtt_app/verify_setup.py - System verification script checking all prerequisites

Project Files:

• android_mqtt_app/LifeTracV5_Remote.aia.info - Instructions for creating the Kodular project file

System Integration

The Android app option is now documented alongside the ESP32 hardware remote in the main LifeTrac v25 README, giving users two control options:

1. ESP32 Hardware Remote: Physical joysticks with dedicated hardware
2. Android MQTT App: Smartphone/tablet with virtual joysticks

Both options use the same MQTT broker (Mosquitto on Raspberry Pi) and are fully interchangeable during operation.

Distribution Options

The implementation supports multiple distribution channels:

• F-Droid: Open-source app store (requires conversion to native Android for reproducible builds)
• Google Play Store: Traditional distribution using Kodular-generated APK
• Direct APK: GitHub releases for sideloading

The F-DROID_SUBMISSION_GUIDE.md provides comprehensive instructions for submitting to F-Droid, including conversion requirements, metadata preparation, and alternative options like IzzyOnDroid for easier open-source distribution.

Testing & Verification

Comprehensive testing tools are provided:

• MQTT message listener for debugging app communication
• Android app simulator for testing system integration
• Setup verification script checking network connectivity and MQTT broker status

Requirements

• Android 7.0+ device with WiFi connectivity
• Free Kodular.io account for building the app
• Existing LifeTrac v25 system with MQTT broker configured
• Same network connectivity as other LifeTrac components

This implementation provides a modern, accessible remote control option while maintaining full compatibility with the existing LifeTrac v25 architecture and safety systems.

Fixes #14

Original prompt

---

This section details on the original issue you should resolve

<issue_title>android mqtt app option for v25</issue_title>
<issue_description>for v25, add a new wireless command option using the Kodular.io version of the MIT App Inventor to send mqtt commands to the tractor from a cell phone. Can use yaseralie's robot arm work as an example: https://github.com/yaseralie/Wireless-Robot-Control-Android-MQTT/tree/main it uses the UrsPahoMqttClient1

create a new folder within the v25 folder for Kodular files

Need to create an .aia file and a new readme file to explain how to use the files and kodular website

</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #14

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[dorkmo]

before this is merged i'll manually create an .aia file on the kodular.io website since copilot is unable to generate one. ill attach the file to this pull request to make it easier.

[dorkmo]

how to make joystick in mit app inventor
https://www.youtube.com/watch?v=OnEg_IcMmg4

[dorkmo]

https://ullisroboterseite.de/android-AI2-PahoMQTT-en.html

[dorkmo]

@copilot would this be a more up to date option for using MQTT? Is kodular or MIT App Inventor better for our project? https://ullisroboterseite.de/android-AI2-PahoMQTT-en.html

[Copilot]

@copilot would this be a more up to date option for using MQTT? Is kodular or MIT App Inventor better for our project? https://ullisroboterseite.de/android-AI2-PahoMQTT-en.html

Based on the current implementation and project requirements, here's my analysis:

Kodular vs MIT App Inventor:

• Kodular (recommended for this project): More extensions, better MQTT support with UrsPahoMqttClient, more modern UI components, and active development
• MIT App Inventor: More established but limited extension ecosystem

MQTT Options:
The current implementation using UrsPahoMqttClient in Kodular is the most robust option because:

• Native Android MQTT library (Eclipse Paho)
• Handles reconnection automatically
• Better performance for real-time control (20Hz messages)
• Production-ready for industrial applications

Alternative MQTT approaches:

• Web-based MQTT over WebSockets: Higher latency, not ideal for real-time control
• Custom extensions: More complex development, harder to maintain

For LifeTrac v25's real-time control requirements (50ms message intervals), the current Kodular + UrsPahoMqttClient approach provides the best balance of reliability, performance, and ease of development. The architecture supports the critical 1-second safety timeout and emergency stop functionality needed for heavy machinery control.

[dorkmo]

@copilot please create instructions on how to submit the app to the f-droid store

[Copilot]

@copilot please create instructions on how to submit the app to the f-droid store

Created comprehensive F-Droid submission guide in commit 895d5d9 (updating).

Added: F-DROID_SUBMISSION_GUIDE.md (11.6KB) covering:

• Complete F-Droid submission process
• Converting Kodular to native Android for F-Droid compliance
• Metadata preparation and repository setup
• Alternative options (IzzyOnDroid, self-hosted F-Droid repo)
• Maintenance and troubleshooting

Important note: Kodular apps require conversion to native Android for F-Droid's reproducible build requirements. The guide explains this challenge and provides alternatives for easier open-source distribution while maintaining the Kodular version for development ease.

Also updated README.md and QUICK_START.md to reference F-Droid distribution options alongside Google Play and direct APK distribution.

[dorkmo]

@copilot lets abandon this and adapt to using https://github.com/UmerCodez/DroidPad . i'll close this pull request.

[dorkmo]

closing in favor of https://github.com/UmerCodez/DroidPad