Online Serial Port Debugger

Core API: Web Serial API

The tool is built on the Web Serial API, which provides JavaScript interfaces to access serial ports through the browser.

Main Features:

• Native browser serial port access without installing drivers or plugins
• Supports multiple serial port configurations (baud rate, data bits, parity, stop bits, flow control)
• Bidirectional data communication using Readable/Writable Streams
• Asynchronous operations based on Promises and async/await

Implementation Steps

const port = await navigator.serial.requestPort();

await port.open({
  baudRate: 9600,
  dataBits: 8,
  parity: 'none',
  stopBits: 1,
  flowControl: 'none'
});

const reader = port.readable.getReader();
while (true) {
  const { value, done } = await reader.read();
  if (done) break;
  // Process received data (Uint8Array)
  const text = new TextDecoder().decode(value);
}

const writer = port.writable.getWriter();
const encoder = new TextEncoder();
const data = encoder.encode('Hello Serial!');
await writer.write(data);

await reader.cancel();
await reader.releaseLock();
await writer.releaseLock();
await port.close();

Key APIs Used

• navigator.serial.requestPort() - Request user to select a serial port
• port.open(options) - Open serial port with configuration
• port.readable.getReader() - Get read stream reader
• port.writable.getWriter() - Get write stream writer
• reader.read() - Read data from serial port
• writer.write(data) - Write data to serial port
• TextDecoder / TextEncoder - Convert between strings and byte arrays
• port.addEventListener('disconnect') - Listen for device disconnect events