Implement color wiper

src/src.ino

@@ -19,9 +19,14 @@
 MAX1704 fuelGauge;
 float charge_percent;
 uint8_t brightness;
-uint16_t color;
+uint16_t raw_color;
+uint8_t color;
 bool always_on = false;
 Adafruit_NeoPixel neopix = Adafruit_NeoPixel(NEO_PIX_NUM, NEO_PIN, NEO_GRB + NEO_KHZ800);
+uint8_t rgb[3]; // index 0 = red / index 1 = green / index 2 = blue
+
+// Various function definitions
+uint8_t* hsvToRgb(int h, double s, double v); // See end of file for implementation
 
 void setup() {
   Serial.begin(9600);
@@ -61,13 +66,18 @@ void setup() {
 void loop() {
   // Read various values needed
   charge_percent = fuelGauge.stateOfCharge(); // Battery level
-  brightness = map(analogRead(POT_BRIGHT_PIN), 0, 1023, 0, 255); // Brightness (0-1023) mapped to 0-255
-  color = analogRead(POT_COLOR_PIN); // Color (0-1023 mapped to color wheel)
+  brightness = map(analogRead(POT_BRIGHT_PIN), 0, 1024, 0, 255); // Brightness (0-1023) mapped to 0-255
+  raw_color = analogRead(POT_COLOR_PIN); // Color (0-1024)
   always_on = (digitalRead(BUTTON_CAP_TOGGLE) == HIGH); // Toggle button pressed == ALWAYS ON
+  
+  // Convert raw color value to position on a circle and then use the circle position to figure out color on a color wheel
+  color = map(raw_color, 0, 1024, 0, 360);
+  hsvToRgb(color, 1, 1); // set rgb byte array
 
   // NeoPixel related
-  neopix.setPixelColor(0, neopix.Color(255, 255, 255)); // White
-  neopix.setPixelColor(1, neopix.Color(0, 0, 255)); // Blue
+  for (uint8_t i=0; i<NEO_PIX_NUM; i++) {
+    neopix.setPixelColor(i, neopix.Color(rgb[0], rgb[1], rgb[2]));
+  }
   neopix.show();
   neopix.setBrightness(brightness);
 
@@ -79,9 +89,71 @@ void loop() {
     Serial.println(brightness);
     Serial.print("Color: ");
     Serial.println(color);
+    Serial.print("Red: ");
+    Serial.println(rgb[0]);
+    Serial.print("Green: ");
+    Serial.println(rgb[1]);
+    Serial.print("Blue: ");
+    Serial.println(rgb[2]);
     Serial.print("Always on: ");
     Serial.println(always_on);
     Serial.println("----------");
-    delay(1000);
+    delay(250);
   }
 }
+
+// Convert degrees on a circle to color values
+//   http://www.skylark-software.com/2011/01/arduino-notebook-rgb-led-and-color_21.html
+uint8_t* hsvToRgb(int h, double s, double v) {
+  // Make sure our arguments stay in-range
+  h = max(0, min(360, h));
+  s = max(0, min(1.0, s));
+  v = max(0, min(1.0, v));
+  if(s == 0) {
+    // Achromatic (grey)
+    rgb[0] = rgb[1] = rgb[2] = round(v * 255);
+    return rgb;
+  }
+  double hs = h / 60.0; // sector 0 to 5
+  int i = floor(hs);
+  double f = hs - i; // factorial part of h
+  double p = v * (1 - s);
+  double q = v * (1 - s * f);
+  double t = v * (1 - s * (1 - f));
+  double r, g, b;
+  switch(i) {
+    case 0:
+      r = v;
+      g = t;
+      b = p;
+      break;
+    case 1:
+      r = q;
+      g = v;
+      b = p;
+      break;
+    case 2:
+      r = p;
+      g = v;
+      b = t;
+      break;
+    case 3:
+      r = p;
+      g = q;
+      b = v;
+      break;
+    case 4:
+      r = t;
+      g = p;
+      b = v;
+      break;
+    default: // case 5:
+      r = v;
+      g = p;
+      b = q;
+  }
+  rgb[0] = round(r * 255.0);
+  rgb[1] = round(g * 255.0);
+  rgb[2] = round(b * 255.0);
+  return rgb;
+}