137 lines
4.2 KiB
C++
137 lines
4.2 KiB
C++
// LED Audio Spectrum Analyzer Display
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//
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// Creates an impressive LED light show to music input
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// using Teensy 3.1 with the OctoWS2811 adaptor board
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// http://www.pjrc.com/store/teensy31.html
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// http://www.pjrc.com/store/octo28_adaptor.html
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//
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// Line Level Audio Input connects to analog pin A3
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// Recommended input circuit:
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// http://www.pjrc.com/teensy/gui/?info=AudioInputAnalog
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//
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// This example code is in the public domain.
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#define USE_OCTOWS2811
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#include <OctoWS2811.h>
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#include <FastLED.h>
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#include <Audio.h>
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#include <Wire.h>
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#include <SD.h>
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#include <SPI.h>
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// The display size and color to use
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const unsigned int matrix_width = 60;
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const unsigned int matrix_height = 32;
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const unsigned int myColor = 0x400020;
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// These parameters adjust the vertical thresholds
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const float maxLevel = 0.5; // 1.0 = max, lower is more "sensitive"
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const float dynamicRange = 40.0; // total range to display, in decibels
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const float linearBlend = 0.3; // useful range is 0 to 0.7
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CRGB leds[matrix_width * matrix_height];
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// Audio library objects
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AudioInputAnalog adc1(A3); //xy=99,55
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AudioAnalyzeFFT1024 fft; //xy=265,75
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AudioConnection patchCord1(adc1, fft);
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// This array holds the volume level (0 to 1.0) for each
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// vertical pixel to turn on. Computed in setup() using
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// the 3 parameters above.
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float thresholdVertical[matrix_height];
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// This array specifies how many of the FFT frequency bin
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// to use for each horizontal pixel. Because humans hear
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// in octaves and FFT bins are linear, the low frequencies
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// use a small number of bins, higher frequencies use more.
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int frequencyBinsHorizontal[matrix_width] = {
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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2, 2, 2, 2, 2, 2, 2, 2, 2, 3,
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3, 3, 3, 3, 4, 4, 4, 4, 4, 5,
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5, 5, 6, 6, 6, 7, 7, 7, 8, 8,
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9, 9, 10, 10, 11, 12, 12, 13, 14, 15,
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15, 16, 17, 18, 19, 20, 22, 23, 24, 25
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};
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// Run setup once
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void setup() {
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// the audio library needs to be given memory to start working
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AudioMemory(12);
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// compute the vertical thresholds before starting
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computeVerticalLevels();
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// turn on the display
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FastLED.addLeds<OCTOWS2811>(leds,(matrix_width * matrix_height) / 8);
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}
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// A simple xy() function to turn display matrix coordinates
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// into the index numbers OctoWS2811 requires. If your LEDs
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// are arranged differently, edit this code...
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unsigned int xy(unsigned int x, unsigned int y) {
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if ((y & 1) == 0) {
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// even numbered rows (0, 2, 4...) are left to right
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return y * matrix_width + x;
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} else {
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// odd numbered rows (1, 3, 5...) are right to left
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return y * matrix_width + matrix_width - 1 - x;
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}
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}
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// Run repetitively
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void loop() {
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unsigned int x, y, freqBin;
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float level;
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if (fft.available()) {
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// freqBin counts which FFT frequency data has been used,
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// starting at low frequency
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freqBin = 0;
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for (x=0; x < matrix_width; x++) {
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// get the volume for each horizontal pixel position
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level = fft.read(freqBin, freqBin + frequencyBinsHorizontal[x] - 1);
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// uncomment to see the spectrum in Arduino's Serial Monitor
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// Serial.print(level);
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// Serial.print(" ");
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for (y=0; y < matrix_height; y++) {
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// for each vertical pixel, check if above the threshold
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// and turn the LED on or off
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if (level >= thresholdVertical[y]) {
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leds[xy(x,y)] = CRGB(myColor);
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} else {
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leds[xy(x,y)] = CRGB::Black;
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}
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}
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// increment the frequency bin count, so we display
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// low to higher frequency from left to right
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freqBin = freqBin + frequencyBinsHorizontal[x];
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}
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// after all pixels set, show them all at the same instant
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FastLED.show();
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// Serial.println();
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}
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}
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// Run once from setup, the compute the vertical levels
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void computeVerticalLevels() {
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unsigned int y;
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float n, logLevel, linearLevel;
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for (y=0; y < matrix_height; y++) {
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n = (float)y / (float)(matrix_height - 1);
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logLevel = pow10f(n * -1.0 * (dynamicRange / 20.0));
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linearLevel = 1.0 - n;
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linearLevel = linearLevel * linearBlend;
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logLevel = logLevel * (1.0 - linearBlend);
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thresholdVertical[y] = (logLevel + linearLevel) * maxLevel;
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}
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}
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