LED LIGHTS

Getting Started

0:00 - 1:51

27:33 - 29:19

Run the Arduino IDE Program

Good idea to right click on it and

Pin to Taskbar

​

Preferences

Plug In

• Plug the USB cable into the Ardunio and the computer
• Wait a minute for USB drivers to load

​

Setup 1

make sure Arduino Uno is selected in Tools -> Board ...

Setup 2

select the COM port¹ that's been assigned to the Arduino in Tools -> Port

make sure to click to get the checkmark

You may have to do this EVERY time you plug in an arduino

COM1 will NOT work

¹usually the highest numbered COM

Verify Setup

at bottom right it should now indicate that your Arduino Uno is connected to the COM port

Blink

load the Blink program into the arduino editor

File -> Examples -> 01. Basics -> Blink

// the setup function runs once when you press reset or power the board

void setup() {

// initialize digital pin 13 as an output.

pinMode(LED_BUILTIN, OUTPUT);

}

​

// the loop function runs over and over again forever

void loop() {

digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (i.e. voltage HIGH)

delay(1000); // wait for a second

digitalWrite(LED_BUILTIN, LOW); // turn the LED off (i.e. voltage LOW)

delay(1000); // wait for a second

}

Blink

upload the Blink program to the Arduino by clicking on

Blink a LED on the Arduino

one small LED light on the Arduino should now be blinking

FastLED library

FastLED is a fast, efficient, easy-to-use Arduino library for programming addressable LED strips and pixels such as WS2810, WS2811, LPD8806, Neopixel and more. FastLED is used by thousands of developers, in countless art and hobby projects, and in numerous commercial products.

​

FastLED documentation

​

FastLED library

Download the FASTLED-3.5.0.zip file (released Jan 2022)

​

​

FastLED library

install the FastLED library

Sketch -> Include Library-> Add .Zip Libraries...

and select your downloaded zip file

Contributed libraries like FastLED are installed in Documents\Arduino\libraries\FastLED-3.5.0

​

FastLED library

verify that the FastLED library is installed

Do NOT click on FastLED, just make sure it is there

Connecting LED Lights

5V

GND

2

connecting the three wires from the lights to the Arduino

Connecting LED Lights

• connect yellow

wire to pin 2

​

(2) connect red

wire to 5V pin

​

(3) connect black

wire to GND pin

​

File -> New

Replace the default program in the window with the program on the next slide.

50 LED Sample Code

#include <FastLED.h> // include the FastLED library code

​

#define DATA_PIN 2

#define NUM_LEDS 50

#define MAX_BRIGHTNESS 255

#define BRIGHTNESS 100 // MAX is 255

​

CRGB leds[NUM_LEDS]; // array of leds[]

​

// runs once when program starts (see setup code)

void setup() {

Serial.begin(9600); //enables serial output for debugging

FastLED.addLeds<WS2811, DATA_PIN, RGB>(leds, NUM_LEDS).setCorrection(TypicalLEDStrip);

FastLED.setBrightness(BRIGHTNESS);

}

// loops continuously (see loop code)

void loop() {

leds[0]=CRGB::White; // sets leds array element 0 to a color name (e.g. White)

FastLED.show(); // show the values of 50 element leds[] array on 50 LEDs

delay(1000); // pauses for the specified number of milliseconds

leds[0].setRGB(0,0,0); // sets leds array element 0 to a RGB color (e.g. black)

FastLED.show(); // show the values of 50 element leds[] array on 50 LEDs

delay(1000); // pauses for the specified number of milliseconds

}

​

50 LED Sample Code

Each arduino program MUST have a setup() and a loop() function.

#include <FastLED.h> // include the FastLED library code

​

#define DATA_PIN 2

#define NUM_LEDS 50

#define MAX_BRIGHTNESS 255

#define BRIGHTNESS 100 // MAX is 255

​

CRGB leds[NUM_LEDS]; // array of leds[]

​

// runs once when program starts (see setup code)

void setup() {

Serial.begin(9600); //enables serial output for debugging

FastLED.addLeds<WS2811, DATA_PIN, RGB>(leds, NUM_LEDS).setCorrection(TypicalLEDStrip);

FastLED.setBrightness(BRIGHTNESS);

}

50 LED Sample Code Part 1 of 2

Initial functions

// loops continuously (see loop code)

void loop() {

leds[0]=CRGB::White; // sets leds array element 0 to a color name (e.g. White)

FastLED.show(); // show the values of 50 element leds[] array on 50 LEDs

delay(1000); // pauses for the specified number of milliseconds

leds[0].setRGB(0,0,0); // sets leds array element 0 to a RGB color (e.g. black)

FastLED.show(); // show the values of 50 element leds[] array on 50 LEDs

delay(1000); // pauses for the specified number of milliseconds

}

​

​

​

​

​

Upload the program and you should see 1 of the 50 LEDs blinking white.

50 LED Sample Code Part 2 of 2

Initial functions

The 50 element leds[ ] array exists only in the C++ program on your Arduino.

​

Changing a value in the leds[ ] array does NOT change the actual LEDs without calling FastLED.show()

​

just changing a value in leds[ ]

​

the leds[ ] array the actual LEDs

From FastLED Basic Usage

​

the leds[ ] array the actual LEDs

"Making your LEDs actually show colors is a two part process with this library. First, you set the values of the entries in the leds[ ] array to whatever colors you want. Then you tell the library to show your data. Your animation/code/patterns will pretty much consist of this cycle.

​

You can change the value that you set to an LED between calls to show (i.e. leds[ ] = ), and the next time you call show the new value will get written out."

​

Initial functions

To get the 50 values currently in the leds[] array to show up on the 50 actual LEDs use FastLED.show();

​

You will likely need a delay(); before doing the next FastLED.show(); to give some time for the LEDs values to persist.

leds[ ] and FastLED.show(); / FastLED.delay();

// The FastLED library delay() method

FastLED.delay(1000);

// is like doing both a FastLED.show() and an arduino delay()

FastLED.show();

delay(1000);

Initial functions

All your code must be inside a function.

Thus your code must be in the loop() function.

// the setup function runs once when you press reset or power the board

void setup() {

// initialize digital pin 13 as an output.

pinMode(13, OUTPUT);

}

​

// the loop function runs over and over again forever

void loop() {

leds[0]=CRGB::White; // Sets leds array element 0 to a color name (e.g. White)

FastLED.delay(1000); // shows LEDs & pauses for the specified number of milliseconds

leds[0].setRGB(0,0,0); // Sets leds array element 0 to a RGB color (e.g. black)

FastLED.delay(1000); // shows LEDs & pauses for the specified number of milliseconds

​

}

runs once at startup

runs in a loop continuously

Initial functions

You can put your code into

your own function

and then

invoke your function

from within the loop() function.

Initial functions

​

// runs once when program starts (see setup code)

void setup() {

Serial.begin(9600); //enables serial output for debugging

FastLED.addLeds<WS2811, DATA_PIN, RGB>(leds, NUM_LEDS).setCorrection(TypicalLEDStrip);

FastLED.setBrightness(BRIGHTNESS);

}

​

// loops continuously (see loop code)

void loop()

{

blink_light_0_example(); // example that blinks LED 0

}

​

//blink the light closest to the controller

void blink_light_0_example() {

leds[0]=CRGB::White; // Sets leds array element 0 to a color name (e.g. White)

FastLED.delay(1000); // shows LEDs & pauses for the specified number of milliseconds

leds[0].setRGB(0,0,0); // Sets leds array element 0 to a RGB color (e.g. black)

FastLED.delay(1000); // shows LEDs & pauses for the specified number of milliseconds

}

​

There are couple of ways in the FastLED library to set an LED's color

Named color leds[#] = CRGB::Aqua;

​

RGB

color value

leds[i].r = 255; �leds[i].g = 68; �leds[i].b = 221;

​

leds[i].setRGB( 255, 68, 221);

​

​

or in hexadecimal

leds[i] = 0xFF44DD;

​

CHSV(Hue,Saturation,Value) color

leds[i] = CHSV(224, 187, 255);

​

FastLED HSV Color

HUE = 0-255 to specifies the color (see picture below)

Saturation = 0-255

Value (aka brightness) = 0-255 (0=dark, 255=full)

color properities

The leds[] array stores CRGB objects.

​

The CHSV() function converts HSV values to a CRGB object.

CHSV(Hue,Saturation,Value) color

void loop() {

int hue = 50;

​

for (int i=0; i<50; i=i+1) {

leds[i] = CHSV( hue, 255, 255);

}

FastLED.delay(100);

}

​

• Change the color of the first LED (i.e. leds[0])

• Change the color of other LEDs (the light strand has 50 LEDs, try numbers between 0 to 49)
• Change the color of all the LEDs
• Change the color of all the even LEDs to one color and the odd LEDs to another color
• Change one LED at a time one

after the other (slow or fast) first

one color then another.

​

A

Arduino reference

(Structure -> Control structure -> for)

C++ for loop

Try out the WOKWi Simulator - instructions

4 stacks of 6 each

​

​

2 on bottom

4 on top

​

store neatly in even/odd order

video