使用 Web Bluetooth API 发送数据时遇到的问题：排查与解决

const sendStringToDevice = async () => {
    try {
        // Request Bluetooth device
        const device = await navigator.bluetooth.requestDevice({
            filters: [{ name: 'monocle' }],
            optionalServices: [0x2A00],
        });

        // Connect to the device
        const server = await device.gatt.connect();

        // Get the specified service
        const service = await server.getPrimaryService(0x2A00); // 使用服务 UUID

        // Get the specified characteristic
        const characteristic = await service.getCharacteristic(0x2A05); // 使用特征 UUID

        // **重要：启动通知**
        await characteristic.startNotifications();

        characteristic.addEventListener('characteristicvaluechanged',
            (event) => {
                // 从 event.target.value 读取数据
                const value = event.target.value;
                // 将 ArrayBuffer 转换为字符串
                let decoder = new TextDecoder('utf-8');
                let decodedString = decoder.decode(value);
                console.log('Received: ' + decodedString);
            });

        // Convert the string to a UInt8Array (assuming ASCII encoding)
        const encoder = new TextEncoder('utf-8');
        const data = encoder.encode(message);

        // Send the data to the characteristic
        await characteristic.writeValue(data);

        console.log(`String "${message}" sent successfully to monocle`);
    } catch (error) {
        console.error('Error sending string to Bluetooth device:', error);
    }
};