Download the code
There are three code libraries which you'll need for this project. For modern Arduinos, please use the Manage Libraries feature to select the following libraries. For more on working with Arduino libraries, see this guide.
Once you have those two libraries loaded, you can download the code. From the program listing below, select Download File to get at the files. This will save a Zip file of the files to your computer. Remember the location you saved them to. After the download, open the Zip file and get the following files Flora_Pianoglove.h and Flora_Pianoglove.ino. You can move the Flora_Pianoglove directory to your Arduino Sketch directory and be ready to go. Just be sure both the ino and h files are in the same directory.
// SPDX-FileCopyrightText: 2019 Anne Barela for Adafruit Industries
//
// SPDX-License-Identifier: MIT
#include <Wire.h>
#include "Adafruit_TCS34725.h"
#include <Adafruit_NeoPixel.h>
#include "Flora_Pianoglove.h"
// we only play a note when the clear response is higher than a certain number
#define CLEARTHRESHHOLD 2000
#define LOWTONE 1000
#define HIGHTONE 2000
// high C
#define LOWKEY 64
// double high C
#define HIGHKEY 76
// our RGB -> eye-recognized gamma color
byte gammatable[256];
// color sensor
Adafruit_TCS34725 tcs = Adafruit_TCS34725(TCS34725_INTEGRATIONTIME_50MS, TCS34725_GAIN_4X);
// one pixel on pin 6
Adafruit_NeoPixel strip = Adafruit_NeoPixel(1, 6, NEO_GRB + NEO_KHZ800);
void setup() {
Serial.begin(9600);
Serial.println("Color Piano!");
if (tcs.begin()) {
Serial.println("Found sensor");
} else {
Serial.println("No TCS34725 found ... check your connections");
while (1); // halt!
}
strip.begin();
strip.show(); // Initialize all pixels to 'off'
// thanks PhilB for this gamma table!
// it helps convert RGB colors to what humans see
for (int i=0; i<256; i++) {
float x = i;
x /= 255;
x = pow(x, 2.5);
x *= 255;
gammatable[i] = x;
//Serial.println(gammatable[i]);
}
// tone output on OC1A / D9
pinMode(9, OUTPUT);
// toggle output
TCCR1A = _BV(COM1A1);
// PWM phase and freq correct
TCCR1B = _BV(WGM13) | _BV(CS11); // div by 8
setFreq(880);
}
void setFreq(uint16_t f) {
if (f == 0) {
TCCR1B = 0; // turn off
} else {
TCCR1B = _BV(WGM13) | _BV(CS11); // div by 8
}
uint32_t i = F_CPU / 16; // div by 8 and 2
i /= f;
ICR1 = i;
OCR1A = i/2;
}
void loop() {
uint16_t clear, red, green, blue;
tcs.setInterrupt(false); // turn on LED
delay(60); // takes 50ms to read
tcs.getRawData(&red, &green, &blue, &clear);
tcs.setInterrupt(true); // turn off LED
// not close enough to colorful item
if (clear < CLEARTHRESHHOLD) {
setFreq(0);
strip.setPixelColor(0, strip.Color(0, 0, 0)); // turn off the LED
strip.show();
return;
}
Serial.print("C:\t"); Serial.print(clear);
Serial.print("\tR:\t"); Serial.print(red);
Serial.print("\tG:\t"); Serial.print(green);
Serial.print("\tB:\t"); Serial.print(blue);
// Figure out some basic hex code for visualization
uint32_t sum = red;
sum += green;
sum += blue;
sum = clear;
float r, g, b;
r = red; r /= sum;
g = green; g /= sum;
b = blue; b /= sum;
r *= 256; g *= 256; b *= 256;
if (r > 255) r = 255;
if (g > 255) g = 255;
if (b > 255) b = 255;
Serial.print("\t");
Serial.print((int)r, HEX); Serial.print((int)g, HEX); Serial.print((int)b, HEX);
Serial.println();
// OK we have to find the two primary colors
// check if blue is smallest. MEME: fix for 'white'
float remove, normalize;
if ((b < g) && (b < r)) {
remove = b;
normalize = max(r-b, g-b);
} else if ((g < b) && (g < r)) {
remove = g;
normalize = max(r-g, b-g);
} else {
remove = r;
normalize = max(b-r, g-r);
}
// get rid of minority report
float rednorm = r - remove;
float greennorm = g - remove;
float bluenorm = b - remove;
// now normalize for the highest number
rednorm /= normalize;
greennorm /= normalize;
bluenorm /= normalize;
Serial.println();
strip.setPixelColor(0, strip.Color(gammatable[(int)r], gammatable[(int)g], gammatable[(int)b]));
strip.show();
Serial.print(rednorm); Serial.print(", ");
Serial.print(greennorm); Serial.print(", ");
Serial.print(bluenorm); Serial.print(" ");
Serial.println();
float rainbowtone = 0;
if (bluenorm <= 0.1) {
// between red and green
if (rednorm >= 0.99) {
// between red and yellow
rainbowtone = 0 + 0.2 * greennorm;
} else {
// between yellow and green
rainbowtone = 0.2 + 0.2 * (1.0 - rednorm);
}
} else if (rednorm <= 0.1) {
// between green and blue
if (greennorm >= 0.99) {
// between green and teal
rainbowtone = 0.4 + 0.2 * bluenorm;
} else {
// between teal and blue
rainbowtone = 0.6 + 0.2 * (1.0 - greennorm);
}
} else {
// between blue and violet
if (bluenorm >= 0.99) {
// between blue and violet
rainbowtone = 0.8 + 0.2 * rednorm;
} else {
// between teal and blue
rainbowtone = 0;
}
}
Serial.print("Scalar "); Serial.println(rainbowtone);
float keynum = LOWKEY + (HIGHKEY - LOWKEY) * rainbowtone;
Serial.print("Key #"); Serial.println(keynum);
float freq = pow(2, (keynum - 49) / 12.0) * 440;
Serial.print("Freq = "); Serial.println(freq);
//Serial.print((int)r ); Serial.print(" "); Serial.print((int)g);Serial.print(" "); Serial.println((int)b );
setFreq(freq);
}
RgbColor HsvToRgb(HsvColor hsv)
{
RgbColor rgb;
unsigned char region, remainder, p, q, t;
if (hsv.s == 0)
{
rgb.r = hsv.v;
rgb.g = hsv.v;
rgb.b = hsv.v;
return rgb;
}
region = hsv.h / 43;
remainder = (hsv.h - (region * 43)) * 6;
p = (hsv.v * (255 - hsv.s)) >> 8;
q = (hsv.v * (255 - ((hsv.s * remainder) >> 8))) >> 8;
t = (hsv.v * (255 - ((hsv.s * (255 - remainder)) >> 8))) >> 8;
switch (region)
{
case 0:
rgb.r = hsv.v; rgb.g = t; rgb.b = p;
break;
case 1:
rgb.r = q; rgb.g = hsv.v; rgb.b = p;
break;
case 2:
rgb.r = p; rgb.g = hsv.v; rgb.b = t;
break;
case 3:
rgb.r = p; rgb.g = q; rgb.b = hsv.v;
break;
case 4:
rgb.r = t; rgb.g = p; rgb.b = hsv.v;
break;
default:
rgb.r = hsv.v; rgb.g = p; rgb.b = q;
break;
}
return rgb;
}
HsvColor RgbToHsv(RgbColor rgb)
{
HsvColor hsv;
unsigned char rgbMin, rgbMax;
rgbMin = rgb.r < rgb.g ? (rgb.r < rgb.b ? rgb.r : rgb.b) : (rgb.g < rgb.b ? rgb.g : rgb.b);
rgbMax = rgb.r > rgb.g ? (rgb.r > rgb.b ? rgb.r : rgb.b) : (rgb.g > rgb.b ? rgb.g : rgb.b);
hsv.v = rgbMax;
if (hsv.v == 0)
{
hsv.h = 0;
hsv.s = 0;
return hsv;
}
hsv.s = 255 * long(rgbMax - rgbMin) / hsv.v;
if (hsv.s == 0)
{
hsv.h = 0;
return hsv;
}
if (rgbMax == rgb.r)
hsv.h = 0 + 43 * (rgb.g - rgb.b) / (rgbMax - rgbMin);
else if (rgbMax == rgb.g)
hsv.h = 85 + 43 * (rgb.b - rgb.r) / (rgbMax - rgbMin);
else
hsv.h = 171 + 43 * (rgb.r - rgb.g) / (rgbMax - rgbMin);
return hsv;
}
// SPDX-FileCopyrightText: 2019 Anne Barela for Adafruit Industries
//
// SPDX-License-Identifier: MIT
typedef struct RgbColor
{
unsigned char r;
unsigned char g;
unsigned char b;
} RgbColor;
typedef struct HsvColor
{
unsigned char h;
unsigned char s;
unsigned char v;
} HsvColor;
Upload the sketch
For more information on programming your Flora board including the software you need to do so, head over to the Getting Started with Flora guide.
Download & open the PianoGlove MIDI sketch in the Adafruit-Arduino IDE
Connect Flora via USB to your computer
Set Adafruit-Arduino IDE's board setting to "Flora" & upload the sketch.
Once the sketch has been uploaded to the Flora, wait for the onboard red LED to stop flashing, then disconnect the USB cable.
Use Flora's power switch to turn on battery power. After a short load time, the Flora's red LED should go dark and Color Sensor's white LED should now be on.
Connect a powered speaker or headphones to the 3.5mm audio jack and move your new color-sensing index finger close to something colorful to play a musical note through the audio jack.
Try moving the sensor quickly between different bright/dark colors, or 'gate' a note by quickly pulling the sensor away from an object. Experiment with … well, anything that has color!
Page last edited January 19, 2025
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