Thursday, December 11, 2014

Software struggles

Programming is not what i like to do.  With a modified adafruit code that i found for a light up bracelet that i further played with and modified, i kind of got the lights to blink in time with the music.  I wish that i could get it to blink in time with certain frequencies but i didn't get around to figuring out if the microphone can actually do that or not.  Either way here is the code and a video of the blinking.

I learned that you cant share the ground of the mic or the LED strip.  There was some kind of interference caused the LED strip to continuously blink and it was really annoying to say the least.

Here is a video of it working after I cleaned up the ground issue




I didn't get to work with the motor code to get a motor to change speed based on input from the mic.  I figured it would need a PWM port and some kind of combination of our lab code to change the speed of the motor using a square wave, as well as taking input put out by the mic program so that the motor activates in time with the LED blinks.

 Here is the code that got it to work

/*
LED VU meter for Arduino and Adafruit NeoPixel LEDs.

Hardware requirements:
 - Most Arduino or Arduino-compatible boards (ATmega 328P or better).
 - Adafruit Electret Microphone Amplifier (ID: 1063)
 - Adafruit Flora RGB Smart Pixels (ID: 1260)
   OR
 - Adafruit NeoPixel Digital LED strip (ID: 1138)
 - Optional: battery for portable use (else power through USB or adapter)
Software requirements:
 - Adafruit NeoPixel library

Connections:
 - 3.3V to mic amp +
 - GND to mic amp -
 - Analog pin to microphone output (configurable below)
 - Digital pin to LED data input (configurable below)
 See notes in setup() regarding 5V vs. 3.3V boards - there may be an
 extra connection to make and one line of code to enable or disable.

Written by Adafruit Industries.  Distributed under the BSD license.
This paragraph must be included in any redistribution.
*/
 
#include <Adafruit_NeoPixel.h>
 
#define N_PIXELS  15  // Number of pixels in strand
#define MIC_PIN   A0  // Microphone is attached to this analog pin
#define LED_PIN    8  // NeoPixel LED strand is connected to this pin
#define DC_OFFSET  0  // DC offset in mic signal - if unusure, leave 0
#define NOISE     70  // Noise/hum/interference in mic signal
#define SAMPLES   60    // Length of buffer for dynamic level adjustment
#define TOP       (N_PIXELS + 2) // Allow dot to go slightly off scale
#define PEAK_FALL 25  // Rate of peak falling dot
 
byte
  peak      = 0,      // Used for falling dot
  dotCount  = 0,      // Frame counter for delaying dot-falling speed
  volCount  = 5;      // Frame counter for storing past volume data
int
  vol[SAMPLES],       // Collection of prior volume samples
  lvl       = 50,      // Current "dampened" audio level
  minLvlAvg = 0,      // For dynamic adjustment of graph low & high
  maxLvlAvg = 512;
Adafruit_NeoPixel
  strip = Adafruit_NeoPixel(N_PIXELS, LED_PIN, NEO_GRB + NEO_KHZ800);
 
void setup() {
 
  // This is only needed on 5V Arduinos (Uno, Leonardo, etc.).
  // Connect 3.3V to mic AND TO AREF ON ARDUINO and enable this
  // line.  Audio samples are 'cleaner' at 3.3V.
  // COMMENT OUT THIS LINE FOR 3.3V ARDUINOS (FLORA, ETC.):
//  analogReference(EXTERNAL);
 
  memset(vol, 0, sizeof(vol));
  strip.begin();
}
 
void loop() {
  uint8_t  i;
  uint16_t minLvl, maxLvl;
  int      n, height;
 
 
 
  n   = analogRead(MIC_PIN);                        // Raw reading from mic 
  n   = abs(n - 512 - DC_OFFSET); // Center on zero
  n   = (n <= NOISE) ? 0 : (n - NOISE);             // Remove noise/hum
  lvl = ((lvl * 7) + n) >> 3;    // "Dampened" reading (else looks twitchy)
 
  // Calculate bar height based on dynamic min/max levels (fixed point):
  height = TOP * (lvl - minLvlAvg) / (long)(maxLvlAvg - minLvlAvg);
 
  if(height < 0L)       height = 2;      // Clip output
  else if(height > TOP) height = TOP;
  if(height > peak)     peak   = height; // Keep 'peak' dot at top
 
 
  // Color pixels based on rainbow gradient
  for(i=0; i<N_PIXELS; i++) {
    if(i >= height)               strip.setPixelColor(i,   0,   0, 0);
    else strip.setPixelColor(i,Wheel(map(i,0,strip.numPixels()-1,30,150)));
    
  }
 
 
 
  // Draw peak dot  
  if(peak > 0 && peak <= N_PIXELS-1) strip.setPixelColor(peak,Wheel(map(peak,0,strip.numPixels()-1,30,150)));
  
   strip.show(); // Update strip
 
// Every few frames, make the peak pixel drop by 1:
 
    if(++dotCount >= PEAK_FALL) { //fall rate 
      
      if(peak > 0) peak--;
      dotCount = 0;
    }
 
 
 
  vol[volCount] = n;                      // Save sample for dynamic leveling
  if(++volCount >= SAMPLES) volCount = 0; // Advance/rollover sample counter
 
  // Get volume range of prior frames
  minLvl = maxLvl = vol[0];
  for(i=1; i<SAMPLES; i++) {
    if(vol[i] < minLvl)      minLvl = vol[i];
    else if(vol[i] > maxLvl) maxLvl = vol[i];
  }
  // minLvl and maxLvl indicate the volume range over prior frames, used
  // for vertically scaling the output graph (so it looks interesting
  // regardless of volume level).  If they're too close together though
  // (e.g. at very low volume levels) the graph becomes super coarse
  // and 'jumpy'...so keep some minimum distance between them (this
  // also lets the graph go to zero when no sound is playing):
  if((maxLvl - minLvl) < TOP) maxLvl = minLvl + TOP;
  minLvlAvg = (minLvlAvg * 63 + minLvl) >> 6; // Dampen min/max levels
  maxLvlAvg = (maxLvlAvg * 63 + maxLvl) >> 6; // (fake rolling average)
 
}
 
// Input a value 0 to 255 to get a color value.
// The colors are a transition r - g - b - back to r.
uint32_t Wheel(byte WheelPos) {
  if(WheelPos < 85) {
   return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
  } else if(WheelPos < 170) {
   WheelPos -= 85;
   return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  } else {
   WheelPos -= 170;
   return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  }
}

-Charlie

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