IDPL - 3: LED Blinking with Arduino Uno

To interface an LED with Arduino Uno and write a program to blink the LED at a fixed time interval.

\| \|	- \| -------------------------------------------- \|	\| Arduino Digital Pin 8 through 220 Ω resistor \|	\| \|	\| Arduino GND \|	\| \| Working Principle The Arduino sets digital pin 8 as an output. When the pin is set to HIGH, approximately 5 V is applied to the LED through the resistor, causing the LED to glow. When the pin is set to LOW, the voltage is removed and the LED turns OFF. The 220 Ω resistor limits the current flowing through the LED and protects both the LED and Arduino output pin. The program alternates between HIGH and LOW with a delay of 1 second, producing a continuous blinking effect. Arduino Code // © 2025, Cognifront. Member of The IoT Kits Family. // Experiment: LED Blinking with Arduino Uno int ledPin = 8; void setup() { // Set LED pin as an output pinMode(ledPin, OUTPUT); } void loop() { // Turn LED ON digitalWrite(ledPin, HIGH); delay(1000); // Turn LED OFF digitalWrite(ledPin, LOW); delay(1000); } Observation The LED turns ON for 1 second. The LED turns OFF for 1 second. The ON/OFF cycle repeats continuously. The LED therefore appears to blink at a regular interval. Result The LED was successfully interfaced with Arduino Uno and programmed to blink continuously at a 1-second interval. Conclusion This experiment demonstrates basic digital output control using Arduino Uno. It introduces the use of pinMode(), digitalWrite(), and delay() functions for controlling an external electronic component.