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LED Blink

Your first project: it blinks an LED on the Arduino's pin 13 once a second and writes each change to the Serial Monitor. It teaches you to use a breadboard, an LED and a resistor. The board's own L light is also on pin 13, so it blinks along with the LED. No extra library needed.

What you need

• 1 × Arduino Uno R3
• 1 × Breadboard 830 Points (MB-102)
• 1 × LED - Red (5mm)
• 1 × Resistor 470 Ω (1/4W)
• 4 × Jumper Wire - Male/Male

Wiring steps

1. 1

   Plug the LED into the breadboard

   

   Plug the red LED into the top half of the breadboard, in columns 9 and 10. The LED's long (bent) leg is the plus (+) side and goes in column 9; the short leg is the minus (−) side and goes in column 10. An LED plugged in the wrong way round does not light. On a breadboard, the five holes in a column are connected to each other.

   • LED long leg (+) → column 9
   • LED short leg (−) → column 10
2. 2

   Add the resistor

   

   Plug one leg of the resistor into column 5 and the other into column 9, the same column as the LED's long leg. The resistor limits the current through the LED; without it, both the LED and the Arduino's pin can be damaged. The resistor in the picture is 220 Ω (red-red-brown); a 470 Ω (yellow-violet-brown) does the same job, with a slightly dimmer LED. Which way round the resistor goes does not matter.

   • One resistor leg → column 5
   • Other resistor leg → column 9
3. 3

   Connect to the Arduino

   

   Run a red jumper wire from the Arduino's digital pin 13 to the red-striped (+) row at the top of the breadboard, and a black wire from the GND pin next to 13 to the blue-striped (−) row. Then connect the + row to column 5 (the resistor's free end) with a short red wire, and the − row to column 10 (the LED's short leg) with a short black wire. The current flows from pin 13 through the resistor and the LED back to GND.

   • Arduino pin 13 → breadboard + (red) row
   • Arduino GND → breadboard − (blue) row
   • + row → column 5
   • − row → column 10

Arduino sketch

void setup() {
  Serial.begin(9600);      // Seri haberleşmeyi başlat
  pinMode(13, OUTPUT);
}

void loop() {
  digitalWrite(13, HIGH);
  Serial.println("LED Yandi"); // Ekrana durumu yaz
  delay(1000);

  digitalWrite(13, LOW);
  Serial.println("LED Sondu"); // Ekrana durumu yaz
  delay(1000);
}

What the Serial Monitor shows

LED Yandi
LED Sondu
LED Yandi
LED Sondu

What you will see

The LED blinks once a second. The board's L light is also on pin 13, so it blinks along with it.