Turning on entire LED strip

Projects Programming
1

Hi, I am very new to Arduino and programming in general. I have the Arduino Uno and an Adafruit NeoPixel Digital RGB LED Strip (Adafruit NeoPixel Digital RGB LED Strip - White 60 LED [WHITE] : ID 1138 : $99.80 : Adafruit Industries, Unique & fun DIY electronics and kits). I'm trying to write a program to simply turn on the entire strip of lights. I tried following the uberguide on the Adafruit site but I must have messed up because when I upload my code the LED strip either turns off or stays off.

Here is my code:

#include <Adafruit_NeoPixel.h>
#include <avr/power.h>

#define PIN 6
#define NUMPIXELS 12

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

void setup() {
strip.begin();
strip.show(); //Initialize all pixels to 'off'(no color set)- not necessary, just thorough

}

void loop() {
strip.begin();
strip.setPixelColor(12, 255, 0, 255);
strip.show();

}

If anyone can help me out I'd really appreciate it!

2

You do not want the strip.begin in the loop(). Only in setup().

strip.setPixelColor(12, 255, 0, 255);

sets the 13th pixel to CYAN (Red and Blue full on). 13th because in Arduino or C we start counting at zero. You do not have a 13th, so something goes wrong. Set the 0th pixel, then the 1st pixel and so on. Look at http://arduino.cc/en/Reference/For do all in a loop.

Actually if you insert a big delay(x) you will find that all setPixelColor() calls do nothing visible - until you call show when it shows the final result. This is because setPixelColor() builds a memory image of your strip, and show() then sends the memory image to the strip.