// use the FastLED library (someone's pre-written code)
#include <FastLED.h>

// set how many LEDs there are and the data pin.
const int numLeds = 30;
const int ledStripPin = 6;

// this creates an array to reference our LEDs
CRGB leds[numLeds];

void setup() {
  // tells the FastLED code e.g. what LEDs we are using, the data pin
  FastLED.addLeds<NEOPIXEL, ledStripPin>(leds, numLeds);

  // limit the strip's draw to 400mA at 5v
  FastLED.setMaxPowerInVoltsAndMilliamps(5, 400);

  // turns the brightness down (so my eyes don't hurt)
  FastLED.setBrightness(8);
  
  
  
  pinMode(7, INPUT_PULLUP);
}

void loop() {
    if (digitalRead(7) == LOW) {
      turnAllWhite();
    } 
  }

void turnAllWhite() {
 for (int light=0; light<30; light++) {
   int timeStep = 0 ;
   timeStep += 1 / 3;
    leds[light].setRGB(10+100*timeStep, 0, 0);
    FastLED.show();
    delay(30);
  }
}