Fix #8: WebSerial Communication Issues with Ender 3 v2

[nkymut]

Changes Made

1. Added async port handling

   • New connectPrinter() method for explicit connection
     • Clearer API for connecting to printer (fab.connectPrinter())
   • added async/await for port opening

   async connectPrinter() {
     try {
       await this.serial.requestPort();
       // Port selection triggers portavailable event handler
     } catch (err) {
       console.error("Failed to request port:", err);
       this.emit("error", err);
     }
   }

2. Improved port opening event handlers

   • Convert callbacks to async/await
   • Added error handling

   this.serial.on("portavailable", async () => {
     try {
       await this.serial.open({ baudRate: this.baudRate });
       console.log("Port opened successfully");
     } catch (err) {
       console.error("Failed to open port:", err);
     }
   });

3. Added a message buffer for command queue management

   • Clear command buffer after copying

   this.commandStream = [...this.commands];
   this.commands = []; // Clear commands after copying

4. Improved message processing

   • Added basic logging for received messages
   • Added handlers for responses
   • Fixed position reporting parsing

Testing

Tested with Ender 3 v2:

• Connection process
• Control panel example
• Multiple commands execute in sequence
• Position reporting works throughout operation
• Auto-home and movement commands
• Nozzle and headbed temp control
• midi thingy
• fabscribe

Fixes #8