Lab 1: Blinking LEDs


I used an Arduino UNO, a blue LED, a red LED, and two 220 ohm resistors. I changed the Arduino sample code to blink one LED twice, then blink the other LED once.


  • Arduino UNO
  • 1 blue LED
  • 1 red LED
  • 2 220 ohm resistors
  • a breadboard


Blinks 2 LEDs, the 1st for 2 beats,
and the 2nd for 1 beat.
Code was modified from the Arduino sample code Blink_1_LEDs
int ledPin1 = 4; //allow for variable output pin
int ledPin2 = 13; //allow for variable output pin
void setup()
pinMode(ledPin1, OUTPUT); // initialize output pins
pinMode(ledPin2, OUTPUT);
void loop() // the loop function runs repeatedly
digitalWrite(ledPin1, HIGH); // turn the LED1 on
delay(800); // wait
digitalWrite(ledPin1, LOW); // turn the LED1 off
digitalWrite(ledPin1, HIGH);
digitalWrite(ledPin1, LOW);
digitalWrite(ledPin2, HIGH); // turn the LED2 on
digitalWrite(ledPin2, LOW); // turn the LED2 off

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