Arduino Project
Light Show 2.0
Course Introduction
In this lesson, you will learn how to use Arduino along with LEDs, and resistors to create a light show.
Note
If this is your first time working with an Arduino project, we recommend downloading and reviewing the basic materials first.
1.1 Install Arduino IDE(Important)
1.2 Introduction of Arduino IDE
Wiring
Common Connections:
LEDS
Connect the LEDs cathode to negative power bus on the breadboard, and the LEDs anode to a 1kΩ resistor then to the 2 to 13 on the Arduino.
Writing the Code
Note
You can copy this code into Arduino IDE.
Don’t forget to select the board(Arduino UNO R4 Minima) and the correct port before clicking the Upload button.
// =========================================
// LED Light Show - For Beginners
// Created for 12 LEDs connected to pins 2–13
// -----------------------------------------
// Effect 1: Ping-Pong
// Effect 2: Waterfall
// Effect 3: Wave (two rounds)
// Effect 4: Bouncing (two rounds)
// Effect 5: Progressive Keep (two directions)
// Effect 6: Running Back
// Effect 7: Ladder (two directions)
// Effect 8: Alternating
// Effect 9: Grouped Flash (two times)
// Effect 10: Cross Blink (two times)
// =========================================
const int ledPins[] = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13};
const int numLeds = 12;
void setup() {
// Set all LED pins as outputs
for (int i = 0; i < numLeds; i++) {
pinMode(ledPins[i], OUTPUT);
digitalWrite(ledPins[i], LOW);
}
}
void loop() {
pingPongEffect(); // Effect 1
waterfallEffect(); // Effect 2
waveEffect(); // Effect 3
bouncingEffect(); // Effect 4
progressiveKeepEffect(); // Effect 5
runningBackEffect(); // Effect 6
ladderEffect(); // Effect 7
alternatingEffect(); // Effect 8
// Keep consistent loop structure for repeated effects
for (int i = 0; i < 2; i++) {
groupedFlashEffect(); // Effect 9 - Repeat twice
}
for (int i = 0; i < 2; i++) {
crossBlinkEffect(); // Effect 10 - Repeat twice
}
}
// -------------------------------
// Effect 1: Ping-Pong
// -------------------------------
void pingPongEffect() {
// Move light from left to right
for (int i = 0; i < numLeds; i++) {
digitalWrite(ledPins[i], HIGH);
delay(80);
digitalWrite(ledPins[i], LOW);
}
// Move light from right to left
for (int i = numLeds - 1; i >= 0; i--) {
digitalWrite(ledPins[i], HIGH);
delay(80);
digitalWrite(ledPins[i], LOW);
}
}
// -------------------------------
// Effect 2: Waterfall
// -------------------------------
void waterfallEffect() {
// Flow from left to right
for (int i = 0; i < numLeds; i++) {
digitalWrite(ledPins[i], HIGH);
delay(50);
}
for (int i = 0; i < numLeds; i++) {
digitalWrite(ledPins[i], LOW);
delay(50);
}
// Flow from right to left
for (int i = numLeds - 1; i >= 0; i--) {
digitalWrite(ledPins[i], HIGH);
delay(50);
}
for (int i = numLeds - 1; i >= 0; i--) {
digitalWrite(ledPins[i], LOW);
delay(50);
}
}
// -------------------------------
// Effect 3: Wave (two rounds)
// -------------------------------
void waveEffect() {
for (int repeat = 0; repeat < 2; repeat++) {
// Left to right wave
for (int i = 0; i < numLeds; i++) {
digitalWrite(ledPins[i], HIGH);
if (i > 1) digitalWrite(ledPins[i - 2], LOW);
delay(50);
}
// Right to left wave
for (int i = numLeds - 1; i >= 0; i--) {
digitalWrite(ledPins[i], HIGH);
if (i < numLeds - 2) digitalWrite(ledPins[i + 2], LOW);
delay(50);
}
// Turn off last two LEDs
for (int i = 0; i < 2; i++) {
digitalWrite(ledPins[numLeds - 1 - i], LOW);
}
}
}
// -------------------------------
// Effect 4: Bouncing (two rounds)
// -------------------------------
void bouncingEffect() {
for (int repeat = 0; repeat < 2; repeat++) {
// Move inward
for (int i = 0; i < numLeds / 2; i++) {
digitalWrite(ledPins[i], HIGH);
digitalWrite(ledPins[numLeds - 1 - i], HIGH);
delay(50);
}
// Turn off inward
for (int i = 0; i < numLeds / 2; i++) {
digitalWrite(ledPins[i], LOW);
digitalWrite(ledPins[numLeds - 1 - i], LOW);
delay(50);
}
// Move outward
for (int i = numLeds / 2 - 1; i >= 0; i--) {
digitalWrite(ledPins[i], HIGH);
digitalWrite(ledPins[numLeds - 1 - i], HIGH);
delay(50);
}
// Turn off outward
for (int i = numLeds / 2 - 1; i >= 0; i--) {
digitalWrite(ledPins[i], LOW);
digitalWrite(ledPins[numLeds - 1 - i], LOW);
delay(50);
}
}
}
// -------------------------------
// Effect 5: Progressive Keep (two directions)
// -------------------------------
void progressiveKeepEffect() {
// Left to right progressive
for (int round = 0; round < numLeds; round++) {
for (int i = 0; i < numLeds; i++) digitalWrite(ledPins[i], LOW);
for (int i = numLeds - 1; i >= numLeds - round; i--) {
digitalWrite(ledPins[i], HIGH);
}
for (int i = 0; i < numLeds - round; i++) {
digitalWrite(ledPins[i], HIGH);
if (i > 0) digitalWrite(ledPins[i - 1], LOW);
delay(50);
}
if (numLeds - round - 1 >= 0) digitalWrite(ledPins[numLeds - round - 1], LOW);
}
// Right to left progressive
for (int round = 0; round < numLeds; round++) {
for (int i = 0; i < numLeds; i++) digitalWrite(ledPins[i], LOW);
for (int i = 0; i < round; i++) digitalWrite(ledPins[i], HIGH);
for (int i = numLeds - 1; i >= round; i--) {
digitalWrite(ledPins[i], HIGH);
if (i < numLeds - 1) digitalWrite(ledPins[i + 1], LOW);
delay(50);
}
if (round < numLeds) digitalWrite(ledPins[round], LOW);
}
}
// -------------------------------
// Effect 6: Running Back
// -------------------------------
void runningBackEffect() {
// Forward
for (int i = 0; i < numLeds; i++) {
digitalWrite(ledPins[i], HIGH);
delay(50);
digitalWrite(ledPins[i], LOW);
}
// Backward
for (int i = numLeds - 1; i >= 0; i--) {
digitalWrite(ledPins[i], HIGH);
delay(50);
digitalWrite(ledPins[i], LOW);
}
}
// -------------------------------
// Effect 7: Ladder (two directions)
// -------------------------------
void ladderEffect() {
// Left to right
for (int i = 0; i < numLeds; i++) {
digitalWrite(ledPins[i], HIGH);
delay(50);
}
for (int i = numLeds - 1; i >= 0; i--) {
digitalWrite(ledPins[i], LOW);
delay(50);
}
// Right to left
for (int i = numLeds - 1; i >= 0; i--) {
digitalWrite(ledPins[i], HIGH);
delay(50);
}
for (int i = 0; i < numLeds; i++) {
digitalWrite(ledPins[i], LOW);
delay(50);
}
}
// -------------------------------
// Effect 8: Alternating
// -------------------------------
void alternatingEffect() {
for (int i = 0; i < 5; i++) {
// Even LEDs ON, odd LEDs OFF
for (int j = 0; j < numLeds; j += 2) {
digitalWrite(ledPins[j], HIGH);
if (j + 1 < numLeds) digitalWrite(ledPins[j + 1], LOW);
}
delay(300);
// Even LEDs OFF, odd LEDs ON
for (int j = 0; j < numLeds; j += 2) {
digitalWrite(ledPins[j], LOW);
if (j + 1 < numLeds) digitalWrite(ledPins[j + 1], HIGH);
}
delay(300);
}
// Turn off all LEDs
for (int i = 0; i < numLeds; i++) digitalWrite(ledPins[i], LOW);
}
// -------------------------------
// Effect 9: Grouped Flash
// -------------------------------
void groupedFlashEffect() {
int groupSize = 4; // 4 LEDs per group
for (int g = 0; g < numLeds; g += groupSize) {
for (int i = g; i < g + groupSize && i < numLeds; i++) digitalWrite(ledPins[i], HIGH);
delay(300);
for (int i = g; i < g + groupSize && i < numLeds; i++) digitalWrite(ledPins[i], LOW);
}
}
// -------------------------------
// Effect 10: Cross Blink
// -------------------------------
void crossBlinkEffect() {
for (int repeat = 0; repeat < 2; repeat++) {
// Opposite LEDs ON/OFF alternately
for (int i = 0; i < numLeds / 2; i++) {
digitalWrite(ledPins[i], HIGH);
digitalWrite(ledPins[numLeds - 1 - i], LOW);
}
delay(300);
for (int i = 0; i < numLeds / 2; i++) {
digitalWrite(ledPins[i], LOW);
digitalWrite(ledPins[numLeds - 1 - i], HIGH);
}
delay(300);
}
}