Simple Arduino Serial Monitor Using C# Windows Form

Hits: 207

This project explains how to create your own simple arduino serial monitor. To create the project we are going to use the Visual Studio IDE to make a windows form project. In this project also explained how you can control a simple LED by turning it OFF or ON through the serial monitor.

Circuit Diagram


Materials required:

  1. Arduino Nano
  2. An LED
  3. 220 ohm resistor
  4. A breadboard
  5. connecting wires

Software required:

  1. Arduino IDE
  2. Visual Studio IDE 2015

Arduino code here

Download Arduino Code here:


#define LED 13         // Pin 13 is connected to the LED
char rxChar= 0;         // RXcHAR holds the received command.

//=== function to print the command list:  ===========================
void printHelp(void){
  Serial.println("--- Command list: ---");
  Serial.println("? -> Print this HELP");  
  Serial.println("a -> LED On  \"activate\"");
  Serial.println("d -> LED Off \"deactivate\"");
  Serial.println("s -> LED     \"status\"");  
//---------------- setup ---------------------------------------------
void setup(){
  Serial.begin(9600);   // Open serial port (9600 bauds).
  pinMode(LED, OUTPUT); // Sets pin 13 as OUTPUT.
  Serial.flush();       // Clear receive buffer.
  printHelp();          // Print the command list.

//--------------- loop ----------------------------------------------- 
void loop(){
  if (Serial.available() >0){          // Check receive buffer.
    rxChar =;            // Save character received. 
    Serial.flush();                    // Clear receive buffer.
  switch (rxChar) {
    case 'a':
    case 'A':                          // If received 'a' or 'A':
  if (digitalRead(LED) == LOW){        // If LED is Off:
          digitalWrite(LED,HIGH);      // Turn On the LED.
          Serial.println("LED turned On");
        else Serial.println("LED already On!");

    case 'f':
    case 'F':                          // If received 'd' or 'D':
  if (digitalRead(LED) == HIGH){       // If LED is On:
          digitalWrite(LED,LOW);       // Turn Off the LED.
          Serial.println("LED turned Off");
        else Serial.println("LED already Off!");
    case 's':
    case 'S':                          // If received  's' or 'S':
  if (digitalRead(LED) == HIGH)        // Read LED status.
          Serial.println("LED status: On");
        else Serial.println("LED status: Off");
    case '?':                          // If received a ?:
        printHelp();                   // print the command list.
   //   Serial.print("'");
  //    Serial.println("' is not a command!");


Download Visual Studio Code here: