Count Down Timer Success

After spending a lot more time on forums (https://forums.adafruit.com/viewtopic.php?f=47&t=49649)

I learnt about creating new commands, particularly a reverseColorWipe.

Now I can have the timer light array build up to full quickly and then count down slowly.

The next step will be to add audio signals.

But for now, here is the code...

// Press button to activate the timer.
//All lights come on in a fast bottom to top sequence,
// then lights turn off one at a time, every 3 seconds in a top to bottom sequence

#include <Adafruit_NeoPixel.h>

// Digital IO pin connected to the button. This will be driven with a
// pull-up resistor so the switch pulls the pin to ground momentarily.
// On a high -> low transition the button press logic will execute.
#define BUTTON_PIN   2

#define PIXEL_PIN    6  // Digital IO pin connected to the NeoPixels.

#define PIXEL_COUNT 8 // Number of NeoPixels

// Declare our NeoPixel strip object:
Adafruit_NeoPixel strip(PIXEL_COUNT, PIXEL_PIN, NEO_RGBW + NEO_KHZ800);
// Argument 1 = Number of pixels in NeoPixel strip
// Argument 2 = Arduino pin number (most are valid)
// Argument 3 = Pixel type flags, add together as needed:
//   NEO_RGBW    Pixels are wired for RGBW bitstream (NeoPixel RGBW products)

boolean oldState = HIGH;
int     mode     = 0;    // Currently-active animation mode, 0-9

void setup() {
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  strip.begin(); // Initialize NeoPixel strip object (REQUIRED)
  strip.show();  // Initialize all pixels to 'off'
}

void loop() {
  // Get current button state.
  boolean newState = digitalRead(BUTTON_PIN);

  // Check if state changed from high to low (button press).
  if ((newState == LOW) && (oldState == HIGH)) {
    // Short delay to debounce button.
    delay(20);
    // Check if button is still low after debounce.
    newState = digitalRead(BUTTON_PIN);
    if (newState == LOW) {     // Yes, still low
      if (++mode > 1) mode = 0; // Advance to next mode, wrap around after #1
      switch (mode) {          // Start the new animation...
        case 0:
          colorWipe(strip.Color(  0,   0,   0), 50);    // Black/off
          break;
        case 1:
          colorWipe(strip.Color(255,   0,   0), 50);    // Green
          delay(3000);
          reverseColorWipe(strip.Color(0, 0, 0), 3000);   // Black / off, slowly
         
          break;
      }
    }
  }

  // Set the last-read button state to the old state.
  oldState = newState;
}

// Fill strip pixels one after another with a color. Strip is NOT cleared
// first; anything there will be covered pixel by pixel. Pass in color
// (as a single 'packed' 32-bit value, which you can get by calling
// strip.Color(red, green, blue) as shown in the loop() function above),
// and a delay time (in milliseconds) between pixels.
void colorWipe(uint32_t color, int wait) {
  for (int i = 0; i < strip.numPixels(); i++) { // For each pixel in strip...
    strip.setPixelColor(i, color);         //  Set pixel's color (in RAM)
    strip.show();                          //  Update strip to match
    delay(wait);                           //  Pause for a moment
  }
}

void reverseColorWipe(uint32_t color, int wait) {
  for (int i=(strip.numPixels()-1); i>=0; i--) { // For each pixel in strip...
    strip.setPixelColor(i, color);         //  Set pixel's color (in RAM)
    strip.show();                          //  Update strip to match
    delay(wait);                           //  Pause for a moment
  }
}

And here is the wiring diagram...