Introduction: Control LED Using Serial Monitor
Hello everyone welcome to my first instructable.
In this instructables we are going to learn how to turn LEDs on and off using serial monitor.
Step 1: Gather the Parts
- A breadboard
- A LED
- A 220 ohm resistor
- An Arduino
Step 2: The Code
Upload the following code to your arduino:
void setup()
{
pinMode(13, OUTPUT);
Serial.begin(9600);
while (!Serial);
Serial.println("Input 1 to Turn LED on and 2 to off");
}
void loop() {
if (Serial.available())
{
int state = Serial.parseInt();
if (state == 1)
{
digitalWrite(13, HIGH);
Serial.println("Command completed LED turned ON");
}
if (state == 2)
{
digitalWrite(13, LOW);
Serial.println("Command completed LED turned OFF");
}
}
}
Step 3: Wiring
Hookup all the components according to the circuit diagram above.
Step 4: Done
Now just connect the arduino to your PC now open the serial monitor (To do so navigate through tools>Serial monitor).
Now when you send 1 the LED turns on and turns off when you send 2.
Thanks for viewing. Please write your questions or suggestions below.
Share
Recommendations

We have a be nice policy.
Please be positive and constructive.
1 Questions
plz explain this code , I replaced code state==1 to state 'a' but it not work with alfa a key ? how to change num to alfa keys ????
//Here try this code:
void setup(){
pinMode(13, OUTPUT);
Serial.begin(9600);
while (!Serial);
Serial.println("Input A to Turn LED on and B to off");
}
void loop() {
if (Serial.available()){
char state = (char) Serial.read();
if (state == 'A'){
digitalWrite(13, HIGH);
Serial.println("Command completed LED turned ON");
}
if (state == 'B'){
digitalWrite(13, LOW);
Serial.println("Command completed LED turned OFF");
}
}
delay(100);
}
3 Comments
Great intro to Arduino tutorial
Thanks.
good job boy