[C#] Invio dati via porta seriale ad intervalli

namespace ProvaSeriale
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        // apre la porta seriale all'apertura del programma
        private void Form1_Load(object sender, EventArgs e)
        {
            serialPort1.Open();
        }
        // invia i dati via seriale
        private void button1_Click(object sender, EventArgs e)
        {
            serialPort1.WriteLine(textBox1.Text);
        }
    }
}

public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        int i = 0;
                
        private void Form1_Load(object sender, EventArgs e)
        {
            serialPort1.Open();
            timer1.Enabled = false;
            timer1.Interval = 1000;
        }

        int[] numeri = {1, 2, 3, 4, 5};

        private void timer1_Tick(object sender, EventArgs e)
        {
             i++;
            serialPort1.Write(" " + numeri[i - 1].ToString());
        }

        private void btInvio_Click(object sender, EventArgs e)
        {
            timer1.Start();
        }
    }