WebSockets in Embedded Devices

1. Introduction

WebSockets provide a full-duplex communication channel over a single TCP connection. This is particularly advantageous for embedded devices in robotics, as it allows them to maintain a constant connection with a server for real-time data exchange.

2. Key Concepts

How WebSockets Work

• Initial handshake using HTTP.
• Upgrades the connection to a WebSocket.
• Enables full-duplex communication.

3. Implementation Steps

Follow these steps to implement WebSockets in an embedded device:

1. Choose a WebSocket Library: Select a library compatible with your embedded platform, such as uWebSocket for C/C++.
2. Set Up a WebSocket Server: Your embedded device can act as a WebSocket server or connect to one.

   
   #include 
   
   int main() {
       uWS::Hub h;
   
       h.onMessage([](uWS::WebSocket *ws, char *data, size_t length, uWS::OpCode opCode) {
           ws->send(data, length, opCode);
       });
   
       h.listen(3000);
       h.run();
       return 0;
   }
                       

3. Establish a WebSocket Connection: Connect to the server using the WebSocket protocol.

   
   #include 
   
   uWS::Hub h;
   
   h.onConnection([](uWS::WebSocket *ws, uWS::HttpRequest req) {
       std::cout << "Connected!" << std::endl;
   });
   
   h.connect("ws://localhost:3000");
                       

4. Handle Incoming Messages: Implement message handling logic to process incoming data.

4. Best Practices

Consider the following best practices when implementing WebSockets:

• Use a reliable library that supports your embedded platform.
• Ensure proper error handling for connection issues.
• Implement message validation to avoid injection attacks.
• Optimize performance to handle multiple connections efficiently.

5. FAQ