Example Code for Arduino-RGB LED Lighting Effects
Last revision 2026/01/12
This tutorial will show you how to use Arduino UNO to control the LED strip to display all kinds of different lighting effects such as breathing, flashing etc.
Hardware Preparation
- Hardware
- Arduino UNO ×1
- RGB LED Strip 120LEDs-white ×1
- Several Dupont line
Software Preparation
- Software
- Arduino IDE, click to download Arduino IDE
Wiring Diagram
Other Preparation Work
Click to download Arduino Library. How to install the library?
Sample Code
/***************************************************
* Digital RGB LED Strip 120 LED-Black/White
* ****************************************************
* Control an Light string on like a Breathing LED, repeatedly.
* @author WENZHENG.WANG
* @version V1.0
* @date 2019-1-29
* All above must be included in any redistribution
* ****************************************************/
#include <Adafruit_NeoPixel.h>
#define PIN 7 //The signal pin connected with Arduino
#define LED_COUNT 180 // the amount of the leds of your strip
// Create an instance of the Adafruit_NeoPixel class called "leds".
// That'll be what we refer to from here on...
Adafruit_NeoPixel leds = Adafruit_NeoPixel(LED_COUNT, PIN, NEO_GRB + NEO_KHZ800);
void setup()
{
leds.begin(); // Call this to start up the LED strip.
clearLEDs(); // This function, defined below, turns all LEDs off...
leds.show(); // ...but the LEDs don't actually update until you call this.
}
void loop()
{
for (int i=0; i<LED_COUNT; i++)
{
rainbow(i);
delay(10); // Delay between rainbow slides
}
}
// Sets all LEDs to off, but DOES NOT update the display;
// call leds.show() to actually turn them off after this.
void clearLEDs()
{
for (int i=0; i<LED_COUNT; i++)
{
leds.setPixelColor(i, 0);
}
}
// Prints a rainbow on the ENTIRE LED strip.
// The rainbow begins at a specified position.
// ROY G BIV!
void rainbow(byte startPosition)
{
// Need to scale our rainbow. We want a variety of colors, even if there
// are just 10 or so pixels.
int rainbowScale = 192 / LED_COUNT;
// Next we setup each pixel with the right color
for (int i=0; i<LED_COUNT; i++)
{
// There are 192 total colors we can get out of the rainbowOrder function.
// It'll return a color between red->orange->green->...->violet for 0-191.
leds.setPixelColor(i, rainbowOrder((rainbowScale * (i + startPosition)) % 192));
}
// Finally, actually turn the LEDs on:
leds.show();
}
// Input a value 0 to 191 to get a color value.
// The colors are a transition red->yellow->green->aqua->blue->fuchsia->red...
// Adapted from Wheel function in the Adafruit_NeoPixel library example sketch
uint32_t rainbowOrder(byte position)
{
// 6 total zones of color change:
if (position < 31) // Red -> Yellow (Red = FF, blue = 0, green goes 00-FF)
{
return leds.Color(0xFF, position * 8, 0);
}
else if (position < 63) // Yellow -> Green (Green = FF, blue = 0, red goes FF->00)
{
position -= 31;
return leds.Color(0xFF - position * 8, 0xFF, 0);
}
else if (position < 95) // Green->Aqua (Green = FF, red = 0, blue goes 00->FF)
{
position -= 63;
return leds.Color(0, 0xFF, position * 8);
}
else if (position < 127) // Aqua->Blue (Blue = FF, red = 0, green goes FF->00)
{
position -= 95;
return leds.Color(0, 0xFF - position * 8, 0xFF);
}
else if (position < 159) // Blue->Fuchsia (Blue = FF, green = 0, red goes 00->FF)
{
position -= 127;
return leds.Color(position * 8, 0, 0xFF);
}
else //160 <position< 191 Fuchsia->Red (Red = FF, green = 0, blue goes FF->00)
{
position -= 159;
return leds.Color(0xFF, 0x00, 0xFF - position * 8);
}
}
Result
The LED strip will display a breathing effect after the program is upload successfully.
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