added Goertzel library and restructured files

libraries/Goertzel/goertzel.cpp

@@ -0,0 +1,136 @@
+#include "goertzel.h"
+
+/*
+
+
+  Goertzel formula audio detector
+
+  This code comes from http://www.skovholm.com/cwdecoder , http://www.skovholm.com/decoder11.ino
+
+  Hjalmar skovholm Hansen, Oz1jhm <[email protected]>
+
+
+
+
+*/
+
+#if defined(ARDUINO) && ARDUINO >= 100
+#include "Arduino.h" 
+#else
+#include "WProgram.h"
+#endif
+
+
+
+float coeff = 0;
+float Q1 = 0;
+float Q2 = 0;
+float sine = 0;
+float cosine = 0;  
+//float sampling_freq = GOERTZ_SAMPLING_FREQ;
+//float target_freq = GOERTZ_TARGET_FREQ;
+//float n = GOERTZ_SAMPLES_FLOAT; 
+int testData[GOERTZ_SAMPLES];
+int audioInPin = 0;
+int realstate = LOW;
+int realstatebefore = LOW;
+int filteredstate = LOW;
+unsigned long laststarttime = 0;
+int magnitudelimit = 100;
+float magnitude = 0;
+
+//////////////////////////////
+// Noise Blanker time which //
+// shall be computed so     //
+// this is initial          //
+//////////////////////////////
+
+int nbtime = GOERTZ_NOISE_BLANKER_INITIAL_MS;        
+
+
+Goertzdetector::Goertzdetector(){}
+
+
+void Goertzdetector::init(int _audioInPin){
+  // The basic goertzel calculation
+
+  int k = 0;
+  float	omega = 0;
+  //k = (int) (0.5 + ((n * target_freq) / sampling_freq));
+  k = (int) (0.5 + (((float)GOERTZ_SAMPLES * (float)GOERTZ_TARGET_FREQ) / (float)GOERTZ_SAMPLING_FREQ));
+  //omega = (2.0 * PI * k) / n;
+  omega = (2.0 * PI * k) / (float) GOERTZ_SAMPLES;
+  sine = sin(omega);
+  cosine = cos(omega);
+  coeff = 2.0 * cosine;
+
+  audioInPin = _audioInPin;
+
+}
+
+int Goertzdetector::detecttone(){
+
+
+  // The basic where we get the tone
+
+
+  for (char index = 0; index < GOERTZ_SAMPLES; index++){
+    testData[index] = analogRead(audioInPin);
+  }
+
+  for (char index = 0; index < GOERTZ_SAMPLES; index++){
+	  float Q0;
+	  Q0 = coeff * Q1 - Q2 + (float) testData[index];
+	  Q2 = Q1;
+	  Q1 = Q0;	
+  }
+
+  float magnitudeSquared = (Q1*Q1)+(Q2*Q2)-Q1*Q2*coeff;  // we do only need the real part //
+
+  magnitude = sqrt(magnitudeSquared);
+
+  Q2 = 0;
+  Q1 = 0;
+
+
+  /////////////////////////////////////////////////////////// 
+  // here we will try to set the magnitude limit automatic //
+  ///////////////////////////////////////////////////////////
+
+
+  if (magnitude > GOERTZ_MAGNITUDE_LIMIT_LOW){
+    magnitudelimit = (magnitudelimit + ((magnitude - magnitudelimit) / GOERTZ_MOVING_AVERAGE_FILTER));  /// moving average filter
+  } else {
+	  magnitudelimit = GOERTZ_MAGNITUDE_LIMIT_LOW;
+  }
+
+  ////////////////////////////////////
+  // now we check for the magnitude //
+  ////////////////////////////////////
+
+  if (magnitude > ((float) magnitudelimit * (float) GOERTZ_MAGNITUDE_THRESHOLD)){
+    realstate = HIGH; 
+  } else {
+    realstate = LOW; 
+  }
+
+  ///////////////////////////////////////////////////// 
+  // here we clean up the state with a noise blanker //
+  /////////////////////////////////////////////////////
+
+  if (realstate != realstatebefore){
+    laststarttime = millis();
+  }
+
+  if ((millis()-laststarttime) > nbtime){
+    if (realstate != filteredstate){
+      filteredstate = realstate;
+    }
+  }
+
+
+  realstatebefore = realstate;
+
+  return(filteredstate);
+
+ }

libraries/Goertzel/goertzel.h

@@ -0,0 +1,80 @@
+#ifndef GOERTZEL_H
+#define GOERTZEL_H
+
+
+/*
+
+
+  Goertzel formula audio detector
+
+  This code comes from http://www.skovholm.com/cwdecoder , http://www.skovholm.com/decoder11.ino
+
+  Hjalmar skovholm Hansen, OZ1JHM <[email protected]>
+
+
+	Notes from the original code author, OZ1JHM (with edits from Goody K3NG)
+
+	GOERTZ_SAMPLING_FREQ will be 8928 on a 16 mhz without any prescaler etc., because we need the tone in the center of the bins    
+	you can set GOERTZ_TARGET_FREQ to 496, 558, 744 or 992          
+	then GOERTZ_SAMPLES_INT the number of samples which give the bandwidth
+	which can be (8928 / GOERTZ_TARGET_FREQ) * 1 or 2 or 3 or 4 etc           
+	init is 8928/558 = 16 * 4 = 64 samples                 
+
+	try to take GOERTZ_SAMPLES = 96 or 128 ;o)    
+
+	48 will give you a bandwidth around 186 hz            
+	64 will give you a bandwidth around 140 hz            
+	96 will give you a bandwidth around 94 hz            
+	128 will give you a bandwidth around 70 hz  
+
+	BUT remember that a high GOERTZ_SAMPLES will take a lot of time so you have to find a compromise  
+
+*/
+
+#if defined(_VARIANT_ARDUINO_DUE_X_)
+  // Arduino Due (84 Mhz clock)
+  #define GOERTZ_SAMPLING_FREQ 46872.0
+  #define GOERTZ_SAMPLES 252 //168 //84
+#else
+  // Arduino Uno, Mega (16 Mhz clock)
+  #define GOERTZ_SAMPLING_FREQ 8928.0
+  #define GOERTZ_SAMPLES 64
+#endif
+
+#define GOERTZ_NOISE_BLANKER_INITIAL_MS 6
+#define GOERTZ_TARGET_FREQ 558.0  
+
+
+
+#define GOERTZ_MAGNITUDE_LIMIT_LOW 100
+#define GOERTZ_MAGNITUDE_THRESHOLD	0.6 //0.6
+#define GOERTZ_MOVING_AVERAGE_FILTER 6
+
+
+class Goertzdetector { 
+
+  public:
+    Goertzdetector();
+    void init(int _audioInPin);
+    int detecttone();
+    int testData[GOERTZ_SAMPLES];
+    float magnitude; 
+    int magnitudelimit;
+	int magnitudelimit_low;
+
+  private:  
+
+	float coeff;
+	float Q1;
+	float Q2;
+	float sine;
+	float cosine;  
+	int audioInPin;
+	int realstate;
+	int realstatebefore;
+	int filteredstate;
+	unsigned long laststarttime;
+
+};
+
+#endif //GOERTZEL_H