fusion-zauberstab/firmware/sound_ripple/sound_ripple.cpp

/* soundmems_ripple
 *
 * By: Andrew Tuline
 *
 * Date: August, 2015
 * 
 * Updated: January, 2020
 *
 * Create a ripple from a calculated peak from a sampled microphone
 * 
 * Note: If you are using a microphone powered by the 3.3V signal, such as the Sparkfun MEMS microphone, then connect 3.3V to the AREF pin.
 * 
 */


//#define FASTLED_ALLOW_INTERRUPTS 0                          // Used for ESP8266.
#include <FastLED.h>                                          // FastLED library.
#include "zauberstab.h"
// Fixed definitions cannot change on the fly.
#define LED_DT LED_PIN                                             // Data pin to connect to the strip.
#define LED_CK 11                                             // Clock pin for WS2801 or APA102.
#define COLOR_ORDER GRB                                       // It's GRB for WS2812 and BGR for APA102.
#define LED_TYPE WS2812                                       // Using APA102, WS2812, WS2801. Don't forget to modify LEDS.addLeds to suit.

uint8_t squelch = 7;                                          // Anything below this is background noise, so we'll make it '0'.
int sample;                                                   // Current sample.
float sampleAvg = 0;                                          // Smoothed Average.
float micLev = 0;                                             // Used to convert returned value to have '0' as minimum.
uint8_t maxVol = 11;                                          // Reasonable value for constant volume for 'peak detector', as it won't always trigger.
bool samplePeak = 0;                                          // Boolean flag for peak. Responding routine must reset this flag.

int max_bright = 255;

CRGB leds[NUM_LEDS];
// Ripple variables
uint8_t colour;                                               // Ripple colour is randomized.
int center = 0;                                               // Center of the current ripple.
int step = -1;                                                // -1 is the initializing step.
uint8_t myfade = 255;                                         // Starting brightness.
#define maxsteps 16                                           // Case statement wouldn't allow a variable.



void setup() {
  
  //analogReference(EXTERNAL);                                  // 3.3V reference for analog input.
 
  Serial.begin(115200);

  LEDS.addLeds<LED_TYPE, LED_DT, COLOR_ORDER>(leds, NUM_LEDS);  // Use this for WS2812B
//  LEDS.addLeds<LED_TYPE, LED_DT, LED_CK, COLOR_ORDER>(leds, NUM_LEDS);  // Use this for WS2801 or APA102

  FastLED.setBrightness(max_bright);
  //FastLED.setMaxPowerInVoltsAndMilliamps(5, 500);

} // setup()


void getSample() {
  
  int16_t micIn;                                              // Current sample starts with negative values and large values, which is why it's 16 bit signed.
  static long peakTime;
  
  micIn = analogRead(MIC_PIN);                                // Poor man's analog Read.
  micLev = ((micLev * 31) + micIn) / 32;                      // Smooth it out over the last 32 samples for automatic centering.
  micIn -= micLev;                                            // Let's center it to 0 now.
  micIn = abs(micIn);                                         // And get the absolute value of each sample.
  sample = (micIn <= squelch) ? 0 : (sample + micIn) / 2;     // Using a ternary operator, the resultant sample is either 0 or it's a bit smoothed out with the last sample.
  sampleAvg = ((sampleAvg * 31) + sample) / 32;               // Smooth it out over the last 32 samples.

  if (sample > (sampleAvg+maxVol) && millis() > (peakTime + 50)) {    // Poor man's beat detection by seeing if sample > Average + some value.
    samplePeak = 1;                                                   // Then we got a peak, else we don't. Display routines need to reset the samplepeak value in case they miss the trigger.
    peakTime=millis();                
  }                                                           

}  // getSample()



void ripple() {

  if (samplePeak == 1) {step = -1; samplePeak = 0; }          // If we have a peak, let's reset our ripple.

  fadeToBlackBy(leds, NUM_LEDS, 64);                          // 8 bit, 1 = slow, 255 = fast
  
  switch (step) {

    case -1:                                                  // Initialize ripple variables.
      center = random(NUM_LEDS);
      colour = random8();                                     // More peaks/s = higher the hue colour.
      step = 0;
      break;

    case 0:
      leds[center] = CHSV(colour, 255, 255);                  // Display the first pixel of the ripple.
      step ++;
      break;

    case maxsteps:                                            // At the end of the ripples.
      // step = -1;
      break;

    default:                                                  // Middle of the ripples.
      leds[(center + step + NUM_LEDS) % NUM_LEDS] += CHSV(colour, 255, myfade/step*2);       // Simple wrap.
      leds[(center - step + NUM_LEDS) % NUM_LEDS] += CHSV(colour, 255, myfade/step*2);
      step ++;                                                // Next step.
      break;  
  } // switch step
  
} // ripple()


void loop() {

  getSample();

  EVERY_N_MILLISECONDS(20) {
   ripple();
  }

   FastLED.show();

} // loop()