Neo Pixel Example Code Guide

User Manual:

Open the PDF directly: View PDF PDF.
Page Count: 3

DownloadNeo Pixel Example Code Guide
Open PDF In BrowserView PDF
Arduino NeoPixel Example Guide
NeoPixel Library Reference
The Adafruit Neopixel library has a few functions already written so that you don’t have to. The code is not very well documented if you don’t know
where to look sadly (welcome to the world of free code). This is a brief run down of what is going on so you can reference it later.
When you create a NeoPixel object in code, it will always be in the format:
Adafruit_NeoPixel pixelRing = Adafruit_NeoPixel(numberOfPixels, pixelDataPin, pixelType);
Thankfully you shouldn’t need to worry about the pixelType as it should always be the same (i.e. NEO_GRB + NEO_KHZ800) if you are using the
pixel rings you were given. If you buy extra NeoPixels or other addressable LEDs then you may need to change this.
An Adafruit_NeoPixel object can perform the functions listed below. Functions are always called in the form .functionName written after
whatever name you gave the NeoPixel object
(e.g. nameGivenToPixelRing.clear() )
These functions should always change to a nice orange so that you know you are on the right track (apart from .fill, at least for me).

.begin()
You will need to use this in the setup() of your code. It initialises the pixels and does some background magic so that all the functions work
properly.

.setPixelColor(n, r, g, b)
Set the colour of pixel index n to the RGB colour with values r, g and b. We always index starting from 0, so if you have 10 pixels, the first pixel
would be 0 and the last would be 9. Setting the first pixel to red would look like .setPixelColor(0, 255, 0, 0)

.setPixelColor(n, c)
Just like the above, except the RGB value is bundled into one Hex value. If you have used Adobe or digital colour swatches, then this will look
familiar. Writing the colour in hex, the first 2 digits are the red value, the next 2 are green and the last 2 are blue. A hex number always begins with
0x. So, a bright green colour would have a hex value 0x00FF00. Setting the first pixel to red would look like .setPixelColor(0, 0xFF0000).
You can see this used in the SimpleNeoPixels example (line 25).

.fill(c, i, n)
Fill n number of pixels to the colour c starting from pixel i. This is used in the ColourWheel example (line 26).

.show()
After you have changed the colour of the pixels we need to let them know that they should update. This is when we call .show() .

.clear()
To turn all the pixels off, call this function. Don’t for get to call .show() afterwards.

.setBrightness(b)
Changes the intensity of the current RGB colour of each pixel. Remember, that since there is a limit to the RGB values, you can lose some of the
original hue. Used in the PixelSensorBrightnessExample

.getBrightness()
Get the value of the brightness that is currently set

.getPixelColor(n)
Get the colour value of pixel n

.numPixels()
Get the number of pixels that are currently controllable.

Examples
SimpleNeoPixels
A concise example showing how to light up some pixels, one by one, and demonstrating how to use delay() and for loops to achieve this.
Contrast the number of lines and comments in this example with the Adafruit ‘simple’ example. Both achieve the same result.

Colour Wheel
This example demonstrates writing and then using a function. Line 10 and 11 should be changed to match your wiring and pixel ring. Line 26 is
where we set the actual colour

PixelSensor
No we start getting into some fun stuff. This example will light up n number of pixels depending on the distance that is read. You will need to
download the Ultrasonic library (same way you downloaded the NeoPixel Library).

PixelSensorBrightness
Control brightness of pixels if distance measured is in a certain range.

PixelSensorBrightnessSmooth
Same as above except the transition between brightness values should be smoother. This I because we use a current and target brightness value.
The speed at which we increment towards are target dictates how smooth the transition is,.
Source Exif Data: 
File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.3
Linearized                      : No
Page Count                      : 3
Title                           : NeoPixelExampleCodeGuide.pages
Producer                        : Mac OS X 10.12.6 Quartz PDFContext
Creator                         : Pages
Create Date                     : 2019:01:22 15:56:00Z
Modify Date                     : 2019:01:22 15:56:00Z
EXIF Metadata provided by EXIF.tools

Navigation menu