Raspberry Pi IoT Notification System: Cross-Platform Hardware Integration

Cross-Platform Hardware Notification Gateway

Raspberry Pi 1 IoT system with optimized Python GPIO control, custom C++ TCP server with Windows system tray integration, and PowerShell toast notification system.

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Technical Architecture

Hardware Layer (Raspberry Pi)

• Raspberry Pi Model 1 with BCM GPIO pin mapping
• RGB LED with PWM control via GPIO 23 (Red), 24 (Green), 25 (Blue)
• Tactile button on GPIO 17 with pull-up resistor (GPIO.PUD_UP)
• Active-low LED configuration with voltage regulation

Software Stack

• Python 3 - RPi.GPIO library with state machine for LED control
• C++ Windows Server - Winsock2 API, Windows Shell API, hidden window message pump
• PowerShell - Windows Runtime toast notifications via Windows.UI.Notifications
• Custom TCP Protocol - Port 10709 with UTF-8 message encoding

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Core Technical Implementation

Python GPIO Management (Raspberry Pi)

• RGB LED state machine with set_rgb(r, g, b) function using active-low logic
• Button debouncing algorithm with 200ms delay and edge detection
• Connection state management with color coding:
  • Yellow (1,1,0) - Connection attempt in progress
  • Green (0,1,0) - Connection established
  • Red (1,0,0) - Connection error
  • Blue (0,0,1) - Idle state blinking
• Heartbeat mechanism with null byte transmission every 3 seconds

C++ Windows Server Architecture

• Winsock2 TCP server with INADDR_ANY binding on port 10709
• Hidden window (WinAPI) for system tray integration with custom window class
• NOTIFYICONDATA structure for tray icon management with WM_APP_TRAYICON messages
• Multi-threaded design: main thread handles Windows message pump, worker thread handles TCP connections
• ShellExecuteW for launching PowerShell scripts with hidden window (SW_HIDE)

Communication Protocol

• TCP socket connection with 10-second connection timeout
• Message format: "DEFAULT MESSAGE" string trigger with UTF-8 encoding
• Heartbeat: Empty byte array transmission for connection validation
• Error handling: Exponential backoff with 3-second retry intervals

Windows Toast Notification System

• PowerShell script using Windows.UI.Notifications ToastTemplateType::ToastText02
• Custom XML template manipulation with text node injection
• Windows Runtime type loading via [Windows.UI.Notifications.ToastNotificationManager]
• Custom notifier registration: "Raspberry Pi Notifier"

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Technical Specifications

Hardware: Raspberry Pi 1 Model B, RGB LED, GPIO 17 Button, Resistor Network

Software Versions:

• Python 3.7+ with RPi.GPIO library
• C++11 with Winsock2, Windows API, Shell API
• PowerShell 5.1+ with Windows Runtime support
• Windows 10/11 for toast notifications

Key Algorithms & Patterns:

• Button debouncing using time-based filtering (200ms delay)
• LED state machine with color blending and blink patterns
• TCP socket connection pooling with keep-alive heartbeat
• Windows message pump for system tray event handling
• PowerShell script parameter injection for dynamic notifications

Performance Optimizations:

• Minimal Python footprint with selective GPIO module usage
• C++ server with detached threads for non-blocking TCP operations
• PowerShell script pre-loading of Windows Runtime types
• Efficient memory management in resource-constrained Raspberry Pi 1 environment