使用蓝牙将 ASCII 从 C# 发送到 Arduino

我正在尝试将我的C# Windows Forms应用程序从笔记本电脑连接到Arduino Duemilanove。蓝牙模块连接到 Arduino 上的 Tx 和 Rx 引脚。我的目标是在输入字母"a"时点亮板载 LED，到目前为止还没有成功。我确定蓝牙已与我的笔记本电脑连接，但它没有响应我按下的字母。

C# 代码

public partial class Form1 : Form
{
    private Guid service = BluetoothService.SerialPort;
    private BluetoothClient bluetoothClient;
    public Form1()
    {
        InitializeComponent();
        this.KeyPreview = true;
        this.KeyPress += new KeyPressEventHandler(Form1_KeyPress);
    }
    void Form1_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (e.KeyChar == 'a')
        {
            Stream peerStream = bluetoothClient.GetStream();
            Byte[] buffer = Encoding.ASCII.GetBytes("a");
            peerStream.Write(buffer, 0, buffer.Length);
        }
    }
    private void search_Click(object sender, EventArgs e)
    {
        BluetoothRadio.PrimaryRadio.Mode = RadioMode.Discoverable;
        BluetoothRadio myRadio = BluetoothRadio.PrimaryRadio;
        bluetoothClient = new BluetoothClient();
        Cursor.Current = Cursors.WaitCursor;
        BluetoothDeviceInfo[] bluetoothDeviceInfo = { };
        bluetoothDeviceInfo = bluetoothClient.DiscoverDevices(10);
        comboBox1.DataSource = bluetoothDeviceInfo;
        comboBox1.DisplayMember = "DeviceName";
        comboBox1.ValueMember = "DeviceAddress";
        comboBox1.Focus();
        Cursor.Current = Cursors.Default;
    }
    private void Connect_Click(object sender, EventArgs e)
    {
        if (comboBox1.SelectedValue != null)
        {
            try
            {
                bluetoothClient.Connect(new BluetoothEndPoint((BluetoothAddress)comboBox1.SelectedValue, service));
                MessageBox.Show("Connected");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
    }
}

Arduino Code

int incomingByte = 0;   // For incoming serial data
void setup()
{
    pinMode(13, OUTPUT); // On-board LED as output
    Serial.begin(9600);     // Opens serial port, sets data rate to 9600 bit/s.
}
void loop()
{
    if (Serial.available() > 0)
    {
        // Read the incoming byte:
        incomingByte = Serial.read();
        if (incomingByte == 'a')
            digitalWrite(13, HIGH);
    }
}

我发送的 ASCII 代码是错误还是丢失了什么？