Neo-Pixel LED Strip

Using TinkerCAD software or a real life Arduino, add on a strip of LED’s (in TinkerCAD these can be found by searching ‘Neopixel’ in the search bar).Add an 8 LED Neopixel strip and set it up as in Fig 1.

Fig 1

We cannot simply send an output from the Arduino as in previous exercises. A Neopixel strip requires each LED to have it’s own signal. Sending these signals is quite complex but fortunately for us, Arduinos use something called a ‘library’ function which helps to do some of the hard work for us.

In this example we are going to use a library called Adafruit_NeoPixel which is a pre-setup piece of coding which will allow us to individually set the LEDs.

The example code shown below, allows us to address the LEDs and perform a lighting sequence.

Look at the code carefully and try to see if you can work out what is happening in each segment. Look at the comments to help:

#include <Adafruit_NeoPixel.h>

#define PIN 2 // input pin Neopixel is attached to

#define NUMPIXELS 8 // number of neopixels in strip

Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

int delayval = 100; // timing delay in milliseconds

int redColor = 0;

int greenColor = 0;

int blueColor = 0;

void setup() {

// Initialize the NeoPixel library.

pixels.begin();

}

void loop() {

setColor();

for (int i=0; i < NUMPIXELS; i++) {

// pixels.Color takes RGB values, from 0,0,0 up to 255,255,255

pixels.setPixelColor(i, pixels.Color(redColor, greenColor, blueColor));

// This sends the updated pixel color to the hardware.

pixels.show();

// Delay for a period of time (in milliseconds).

delay(delayval);

}

// setColor()

// picks random values to set for RGB

void setColor(){

redColor = random(0, 255);

greenColor = random(0,255);

blueColor = random(0, 255);

}

Now run the program and see what happens.
Carefully look at the coding shown above and see if you can work out how to change it for different outcomes.

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