#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
#include <avr/power.h>
#endif
#define PIN        8 // data pin (RGB led)
#define NUMPIXELS 1 // rumber of led

Adafruit_NeoPixel pixels(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);  // this is a function from the lib to declare pin num and num of LEDs and the order of LEDs GRB or RGB and the frequency
#define DELAYVAL 500   //  1/2 sec delay 

const int analogInPin = A0;     // declare sensors pins
const int analogInPin1 = A1;
const int analogInPin2 = A2;
const int analogInPin3 = A3;

int sensorValue25  = 0;
int sensorValue50  = 0;
int sensorValue75  = 0;
int sensorValue100 = 0;


void setup() {
#if defined(__AVR_ATtiny44__) && (F_CPU == 8000000)     // attiny typ and CPU f
  clock_prescale_set(clock_div_1);
#endif

  pixels.begin();   // start 
  pixels.clear();   // clear     read more 

}

void loop() {

  sensorValue25  = analogRead(analogInPin);      //read and save the sensor values in sensorValueXX
  sensorValue50  = analogRead(analogInPin1);
  sensorValue75  = analogRead(analogInPin2);
  sensorValue100  = analogRead(analogInPin3);
  
  //100% full
  if ( sensorValue100  > 500) {
    pixels.setPixelColor(0, pixels.Color(0, 0, 255));   //pixels.setPixelColor(led num, pixels.Color(R, G, B)); to set the led color
    pixels.show();   // to show the led color
  }
    //75% left
  else if (( sensorValue100  < 500) && ( sensorValue75 > 500)) {
    pixels.setPixelColor(0, pixels.Color(0, 255, 0));
    pixels.show();
    delay(500);
  }
    //50% left
  else if (( sensorValue100  < 500) && ( sensorValue75 < 500) && ( sensorValue50 > 500)) {
    pixels.setPixelColor(0, pixels.Color(255,255,0));
    pixels.show();
    delay(500);

  }
  //25% left
  else if (( sensorValue100  < 500) && ( sensorValue75 < 500) && ( sensorValue50 < 500) && ( sensorValue25 > 500)) {
    pixels.setPixelColor(0, pixels.Color(255,80,0));
    pixels.show();
    delay(500);

  }
  //NO water left
  else {
    pixels.setPixelColor(0, pixels.Color(255, 0, 0));
    pixels.show();
    delay(500);
    pixels.setPixelColor(0, pixels.Color(0, 0, 0));
    pixels.show();
    delay(500);
  }
}