Web Socket Connect

WebSocket Connect Application

Overview

This application demonstrates a WebSocket client implementation that connects to a server and maintains a persistent connection for real-time communication.

Features

• WebSocket Client Connection: Establishes a connection to a WebSocket server
• Real-time Data Exchange: Sends periodic time tick messages to the server
• Asynchronous Socket Handling: Uses a dedicated task for reading incoming data
• Network Stack Integration: Built on NetBurner's network initialization framework
• Error Handling: Monitors socket status and handles connection errors gracefully

Application Structure

The application consists of two main components:

Main Task (UserMain)

• Initializes the network stack and waits for DHCP
• Establishes WebSocket connection to the specified server
• Sends periodic "TimeTick" messages every second
• Creates a separate task for handling incoming socket data

Socket Handling Task (UserTask)

• Monitors the WebSocket connection using select()
• Handles incoming data from the server
• Manages socket errors and connection cleanup
• Echoes received data to stdout

Configuration

The application is configured with the following default settings:

#define SERVER_IP "192.168.1.209"

• Server IP: 192.168.1.209
• WebSocket Path: "/"
• Port: 80
• Message Interval: 1 second

Key Functions

Connection Management

• NB::WebSocket::Connect(): Establishes WebSocket connection
• NB::WebSocket::ws_flush(): Flushes WebSocket buffers

Network Operations

• select(): Monitors socket file descriptors for activity
• read(): Receives data from the WebSocket
• writestring(): Sends string data through the WebSocket
• writeall(): Outputs received data to stdout

System Integration

• init(): Initializes the NetBurner network stack
• WaitForActiveNetwork(): Waits for network connectivity
• OSSimpleTaskCreatewName(): Creates the socket handling task

Message Format

The application sends periodic status messages in the format:

TimeTick: [current_tick_value]

Where [current_tick_value] is the current system tick count, providing a timestamp for each message.

Error Handling

The application includes robust error handling:

• Socket error detection using select() with error file descriptor sets
• Automatic socket cleanup on connection failure
• Graceful task termination when connection is lost

Build Requirements

• NetBurner development environment
• WebSocket library (websockets.h)
• Standard C libraries
• NetBurner initialization framework (init.h)

Usage

1. Configure the SERVER_IP define to match your WebSocket server
2. Build and deploy to your NetBurner device
3. The application will automatically:
   • Initialize the network stack
   • Connect to the specified WebSocket server
   • Begin sending periodic time tick messages
   • Display any received messages on the console

Technical Details

• Task Priority: Socket handling task runs at MAIN_PRIO + 1
• Buffer Size: Uses ETHER_BUFFER_SIZE for data reception
• Timing: Uses TICKS_PER_SECOND for consistent timing intervals
• Diagnostics: Includes system diagnostics (should be disabled for production)