arduino_music_viz.ino

#include "FastLED.h"
#include "limits.h"

#define NUM_LEDS 60 // How many leds in your strip?
#define DATA_PIN 5 // led data transfer
#define MICROPHONE_PIN A0


long sensorMax = 0;
long sensorMin = LONG_MAX;
const int numReadings = 100;

CRGB leds[NUM_LEDS]; // Define the array of leds
CRGBPalette16 currentPalette;
TBlendType currentBlending;

long readings[numReadings]; // the readings from the analog input
int readIndex = 0; // the index of the current reading
int total = 0;     // the running total
int average = 0;

float exponent = 3.2; // increase the difference between high and low.


void setup()
{
    Serial.begin(9600);
    pinMode(MICROPHONE_PIN, INPUT);

    for (int i = 0; i < numReadings; i++) {
        readings[i] = -1;
    }

    delay(1000); // power-up safety delay

    currentPalette = RainbowColors_p;
    currentBlending = LINEARBLEND;

    FastLED.addLeds<NEOPIXEL, DATA_PIN>(leds, NUM_LEDS);
    FastLED.setBrightness(64 );
    FastLED.show();
}

void loop()
{
    long soundVal = pow(analogRead(A0), exponent);

    readings[readIndex] = soundVal;

    if (readIndex >= numReadings) {
        readIndex = 0;
    }

    sensorMin = findMin(readings, numReadings);
    sensorMax = findMax(readings, numReadings);

    readIndex++;

    int numLeds = (((soundVal-sensorMin)*1.)/(sensorMax-sensorMin))*(NUM_LEDS/2);
    Serial.println(numLeds);
    fillLEDSwithColor(numLeds);

    FastLED.show();
    delay(50);
}

void fillLEDSwithColor(uint8_t currLeds)
{
    int colorIndex = 0;
    int firstRightIdx = NUM_LEDS / 2;
    

    for (int i = 0; i < firstRightIdx; i++) {
        if (i < currLeds) {
            leds[firstRightIdx+i-1] = ColorFromPalette(currentPalette, colorIndex, 255, currentBlending);
            leds[firstRightIdx-i] = ColorFromPalette(currentPalette, colorIndex, 255, currentBlending);
        }
        else {
            leds[firstRightIdx+i-1].fadeToBlackBy(100);
            leds[firstRightIdx-i].fadeToBlackBy(100);
        }

        colorIndex += 10;
    }

    FastLED.show();
}

long findMin(long* arr, int sz)
{
    long minimum = arr[0];
    for (int i = 0; i < sz; i++) {
        if (arr[i] == -1)
            continue;
        if (arr[i] < minimum) {
            minimum = arr[i];
        }
    }
    return minimum;
}

long findMax(long* arr, int sz)
{
    long maximum = arr[0];
    for (int i = 0; i < sz; i++) {
        if (arr[i] > maximum) {
            maximum = arr[i];
        }
    }

    return maximum;
}