create arduino code for ring

This project may be coded in _either_: CircuitPythoin, Arduino, or Microsoft MakeCode Maker. This is the Arduino code. It uses the Adafruit_NeoPixel library.

Gemma_Nano_Ring/NanoRing.ino

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+#include <Adafruit_NeoPixel.h>
+#define PIN 1
+#define NUM_LEDS 3
+
+Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_LEDS, PIN, NEO_GRB + NEO_KHZ800);
+
+//                          R   G   B
+uint8_t myColors[][5] = {
+                         {30, 144, 255},   // dodger blue
+                         {232, 100, 255},  // purple
+                         {204, 0, 204},    //  
+                         {200, 200, 20},   // yellow 
+                         {30, 200, 200},   // blue
+                         };
+                               
+// don't edit the line below
+#define FAVCOLORS sizeof(myColors) / 5
+
+void setup() {
+  strip.begin();
+  strip.setBrightness(20);
+  strip.show(); // Initialize all pixels to 'off'
+}
+
+void loop() {
+  flashRandom(10, 1);  // first number is 'wait' delay, shorter num == shorter twinkle
+  flashRandom(10, 3);  // second number is how many neopixels to simultaneously light up
+  flashRandom(10, 2);
+}
+
+void flashRandom(int wait, uint8_t howmany) {
+ 
+  for(uint16_t i=0; i<howmany; i++) {
+    // pick a random favorite color!
+    int c = random(FAVCOLORS);
+    int red = myColors[c][0];
+    int green = myColors[c][1];
+    int blue = myColors[c][2]; 
+ 
+    // get a random pixel from the list
+    int j = random(strip.numPixels());
+    
+    // now we will 'fade' it in 5 steps
+    for (int x=0; x < 5; x++) {
+      int r = red * (x+1); r /= 5;
+      int g = green * (x+1); g /= 5;
+      int b = blue * (x+1); b /= 5;
+      
+      strip.setPixelColor(j, strip.Color(r, g, b));
+      strip.show();
+      delay(wait);
+    }
+    // & fade out in 5 steps
+    for (int x=5; x >= 0; x--) {
+      int r = red * x; r /= 5;
+      int g = green * x; g /= 5;
+      int b = blue * x; b /= 5;
+      
+      strip.setPixelColor(j, strip.Color(r, g, b));
+      strip.show();
+      delay(wait);
+    }
+  }
+  // LEDs will be off when done (they are faded to 0)
+}