1  // SPDX-FileCopyrightText: 2017 Mikey Sklar for Adafruit Industries
 2  //
 3  // SPDX-License-Identifier: MIT
 4  
 5  #include <Adafruit_NeoPixel.h>
 6  
 7  #define PIN 1
 8  // Parameter 1 = number of pixels in strip
 9  // Parameter 2 = Arduino pin number (most are valid)
10  // Parameter 3 = pixel type flags, add together as needed:
11  //   NEO_KHZ800  800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
12  //   NEO_KHZ400  400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
13  //   NEO_GRB     Pixels are wired for GRB bitstream (most NeoPixel products)
14  //   NEO_RGB     Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
15  Adafruit_NeoPixel strip = Adafruit_NeoPixel(8, PIN, NEO_GRB + NEO_KHZ800);
16  
17  int sensorPin = 1;    // select the input pin for the potentiometer (analog 1 is digital 2)
18  int sensorValue = 0;  // variable to store the value coming from the sensor
19  int colorValue = 0;
20  
21  void setup() {
22    // Set internal pullup resistor for sensor pin (analog 1 is digital 2)
23    pinMode(2, INPUT_PULLUP); 
24    strip.begin();
25    strip.setBrightness(40); //adjust brightness here
26    strip.show(); // Initialize all pixels to 'off'
27  }
28  
29  void loop() {
30    // read the value from the sensor:
31    sensorValue = analogRead(sensorPin);
32    colorValue = map(sensorValue, 0, 1024, 0, 255); //map sensor values from 0-124 to 0-255
33    for (int i = 0; i<strip.numPixels(); i++){
34      strip.setPixelColor(i, Wheel(colorValue)); //use Wheel function to set color
35    }
36    strip.show();                
37  }
38  
39  // Input a value 0 to 255 to get a color value.
40  // The colours are a transition r - g - b - back to r.
41  uint32_t Wheel(byte WheelPos) {
42    if(WheelPos < 85) {
43     return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
44    } else if(WheelPos < 170) {
45     WheelPos -= 85;
46     return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
47    } else {
48     WheelPos -= 170;
49     return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
50    }
51  }