Servo_0.2

#include <Servo.h>

Servo servo1;

void setup() {
  // put your setup code here, to run once:
  servo1.attach(6);
  Serial.begin(9600);
  Serial.println("Start");
}

void loop() {

  if (Serial.available() > 0){
    int i = Serial.parseInt();
    Serial.println(i);
    servo1.write(i);
  }
}

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using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

using System.IO.Ports;

namespace WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        private delegate void SafeCallDelegate(string text);

        public Form1()
        {
            InitializeComponent();

            comboBox1.Items.Clear();
            foreach (string portName in SerialPort.GetPortNames())
            {
                comboBox1.Items.Add(portName);
            }
            comboBox1.SelectedIndex = 0;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            serialPort1.Open();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            serialPort1.Close();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (serialPort1.IsOpen)
            {
                try
                {
                    serialPort1.Write(textBox1.Text);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        }

        private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            SerialPort sp = (SerialPort)sender;
            WriteTextSafe(sp.ReadExisting());
        }

        private void WriteTextSafe(string text)
        {
            if (label1.InvokeRequired)
            {
                var d = new SafeCallDelegate(WriteTextSafe);
                label1.Invoke(d, new object[] { text });
            }
            else
            {
                label1.Text = text;
            }
        }
    }
}