Change Notify

Config Notify Application

Overview

This application demonstrates how to use configuration objects with change notification callbacks in an embedded system. The program creates basic configuration variables and registers callbacks to be notified when these variables change.

Features

• Configuration Management: Creates and manages different types of configuration variables (string, integer, unsigned integer)
• Change Notifications: Implements callback notifications when configuration values are modified
• Interactive Menu System: Provides a command-line interface for viewing and modifying configuration values
• Dynamic Configuration: Supports creating and deleting configuration variables at runtime
• Network Integration: Displays network interface information on startup

Configuration Variables

The application creates three main configuration objects:

1. gSingleString - A string configuration variable with default value "SName"
2. gMyOwnVal - An integer configuration variable with default value 199
3. gMyOwnuVal - An unsigned integer configuration variable with default value 299

Command Interface

The application provides an interactive menu system with the following commands:

• C - Show Config Tree: Displays the complete configuration tree
• S - Show and Set gSingleString: View and modify the string configuration
• V - Show and Set gMyOwnVal: View and modify the integer configuration
• U - Show and Set gMyOwnuVal: View and modify the unsigned integer configuration
• N - New/Create dynamic variable: Creates a new dynamic configuration variable
• D - Delete dynamic variable: Removes the dynamic configuration variable
• Q - Query dynamic variable: Displays the value of the dynamic variable
• ? - Show Command List: Displays all available commands

Notification System

The application implements a notification callback system that:

• Uses a semaphore-based notification mechanism
• Registers callbacks for all configuration variables
• Provides real-time notification when any monitored configuration value changes
• Displays a message when a configuration change is detected

Technical Implementation

Key Components

• Configuration Objects: Uses config_string, config_int, and config_uint types
• Callback System: Implements ConfigNotificationCallBack for change notifications
• Semaphore Synchronization: Uses OS_SEM for thread-safe notification handling
• Storage Management: Automatically saves configuration changes to persistent storage

Memory Management

• Static configuration objects are created at global scope
• Dynamic configuration objects can be created and destroyed at runtime
• Non-static objects require calling FixNonStaticObject() method

Network Information

On startup, the application displays:

• IP address of the first network interface
• AutoIP address
• Gateway address
• Configuration space usage statistics

Usage

1. Startup: The application initializes network interfaces and displays system information
2. Command Entry: Enter single character commands to interact with the configuration system
3. Value Modification: Follow prompts to enter new values for configuration variables
4. Notification Monitoring: The system automatically notifies when values change

Build Information

The application displays build timestamp information on startup, showing when the code was compiled.

Example Workflow

1. Start application and view initial configuration
2. Use 'C' command to see the complete config tree
3. Use 'S', 'V', or 'U' commands to modify configuration values
4. Observe notification messages when values change
5. Use 'N' to create dynamic variables and 'D' to delete them
6. Use 'Q' to query dynamic variable values