// Define port and reader globally to be used in other functions
let port;
let reader
let decoder = new TextDecoder("utf-8");
let counterElement = document.getElementById("counter");

// Request a port and open a connection.
async function connect() {
    port = await navigator.serial.requestPort();
    await port.open({ baudRate: 9600 });
    reader = port.readable.getReader();
    console.log("Port is open!");    
}

// Read data
async function readLoop() {
    // loop until reader.cancel() is called
    while (true) {
        // Wait for data
        const { value, done } = await reader.read();
        // Show the received data in the console        
        if (value) {
            console.log(decoder.decode(value));
        }
        // Exit the loop when done
        if (done) {
            console.log('[readLoop] DONE', done);
            reader.releaseLock();
            break;
        }
    }
}

// Close the port
async function disconnect() {
    await reader.cancel();
    await port.close();
    console.log("Port is closed!");
}