commit c6a4a8eba37737435cc4cce1d4c277457f68b338
Author: Alexander Alber <alexander@alber.engineering>
Date:   Mon Jun 6 14:39:14 2022 +0200

    initial

diff --git a/arduino/beta_arduino_due.ino b/arduino/beta_arduino_due.ino
new file mode 100644
index 0000000..010378f
--- /dev/null
+++ b/arduino/beta_arduino_due.ino
@@ -0,0 +1,215 @@
+#include <FastLED.h>
+
+
+//lichterkette: PWM 2
+//mikrofon: A1
+#define LED_PIN 2
+#define NUM_LEDS 240
+
+
+#define SAMPLING_FREQUENCY_BP 40
+#define SAMPLING_FREQUENCY_CONTROL 1
+#define Q 20.
+#define PI 3.1415926535897932384626433832795
+#define n_BP 20
+
+
+CRGB leds[NUM_LEDS];
+
+unsigned long sampling_period_bp = 1000000L/SAMPLING_FREQUENCY_BP;
+unsigned long sampling_period_control = 1000000L/SAMPLING_FREQUENCY_CONTROL;
+double energy = 0;
+unsigned long last_us_bp = 0L;
+unsigned long last_us_control = 0L;
+
+float a0[n_BP];
+float a1[n_BP];
+float a2[n_BP];
+float b0[n_BP];
+//float b1[n_BP]; 
+float b2[n_BP];
+
+float a[n_BP];
+float w0[n_BP];
+
+float yy1[n_BP];
+float yy2[n_BP];
+float yy3[n_BP];
+float yy4[n_BP];
+float yy5[n_BP];
+float yy6[n_BP];
+
+float u1[n_BP];
+float u2[n_BP];
+float y[n_BP];
+float y_fil[n_BP];
+
+float angle;
+float angle2;
+
+double energy_fil = 800.;
+
+
+float pos_target = NUM_LEDS/2;
+float pos_target_filtered = NUM_LEDS/2;
+
+int microphone_offset;
+long initial_time;
+
+int active = 15;
+int candidate = 15;
+int rounds = 0;
+
+
+
+
+void setup() {
+
+  Serial.begin(115200);
+  
+  FastLED.addLeds<WS2812, LED_PIN, RGB>(leds, NUM_LEDS);
+  FastLED.setMaxPowerInVoltsAndMilliamps(5, 350);
+
+  for(int i = 0; i < NUM_LEDS; i++)
+  { int brightness = get_value(i, pos_target_filtered);
+    leds[i].setRGB(brightness, brightness, brightness); }
+  FastLED.show();
+
+  long sumsamples = 0;
+  for(int j = 1; j<1000; j++)
+  {
+    int sample = analogRead(1);
+    sumsamples += sample;
+    delay(1);
+    if(j==500)
+    {
+      sumsamples = 0;
+    }
+  }
+  microphone_offset = sumsamples/500;      
+  set_filter();
+  initial_time = micros();
+
+  
+}
+
+void set_filter() {
+  for(int i = 0; i < n_BP; i++)
+  {
+    float frequency = 1.75+i*0.033;
+    
+    w0[i] = 2.*PI*frequency/SAMPLING_FREQUENCY_BP;
+    a[i] = sin(w0[i]/(2.*Q)); 
+  
+    b0[i] = a[i];
+    //b1[i] = 0;
+    b2[i] = -a[i];
+    a0[i] = 1.+a[i];
+    a1[i] = -2.*cos(w0[i]);
+    a2[i] = 1.-a[i];
+  }
+}
+
+int get_value(int pos, float pos0) {
+
+  if (abs(pos0-pos) > 7)
+  { return 0; }
+  else
+  { return (255-abs(pos0-pos)*35); }
+
+}
+
+void loop() {
+
+
+   int sample = int(analogRead(1) - microphone_offset);
+
+  
+   energy += abs(sample)*abs(sample);
+   
+   if (micros() - last_us_bp > sampling_period_bp)
+   {
+       last_us_bp += sampling_period_bp;
+       energy_fil += (energy - energy_fil) * 0.01;
+      Serial.println(energy);
+        for(int i = 0; i < n_BP; i++)
+        {
+           y[i] = (b0[i]/a0[i])*energy + 0. + (b2[i]/a0[i])*u2[i] - (a1[i]/a0[i])*yy1[i] - (a2[i]/a0[i])*yy2[i];
+           u2[i] = u1[i];
+           u1[i] = energy;
+           yy6[i] = yy5[i];
+           yy5[i] = yy4[i];
+           yy4[i] = yy3[i];
+           yy3[i] = yy2[i];
+           yy2[i] = yy1[i];
+           yy1[i] = y[i];
+
+           y_fil[i] += (abs(y[i]) - y_fil[i]) * 0.005; //linie der scheitelpunkte
+        }
+
+
+       float delays = constrain( SAMPLING_FREQUENCY_BP * 0.25/(1.75+active*0.033) , 4., 6.);
+
+       float delayed = 0;
+       if (delays > 5)
+       {delayed = yy5[active]*(1-delays+5) + yy6[active]*(delays-5); }
+       else
+       {delayed = yy4[active]*(1-delays+4) + yy5[active]*(delays-4); }
+
+       angle = atan2(delayed , y[active]);
+
+       if (PI < abs(angle - angle2) && abs(angle - angle2)  < 3*PI)
+       { angle2 = angle + 2*PI; }
+       else
+       { angle2 = angle; }
+
+       pos_target = map(angle2, -PI, 3*PI, -0.1*NUM_LEDS, NUM_LEDS*1.1);
+        
+
+
+       if (pos_target > pos_target_filtered)
+       { pos_target_filtered += (pos_target - pos_target_filtered)*0.5; }
+       else
+       { pos_target_filtered = pos_target; }
+
+       energy = 0;
+
+       for(int i = 0; i < NUM_LEDS; i++)
+       { int brightness = get_value(i, pos_target_filtered);
+         leds[i].setRGB(brightness, brightness, brightness); }
+       FastLED.show();
+   }
+
+   if (micros() - last_us_control > sampling_period_control)
+   {          
+      last_us_control += sampling_period_control;
+      int argmax = -1;
+      float valuemax = 0;
+      for(int i = 0; i < n_BP; i++)
+      {
+        if(y_fil[i] > valuemax)
+        {
+          valuemax = y_fil[i];
+          argmax = i;
+        }
+      }
+      
+      if(argmax > -1)
+      {
+          if(argmax == candidate)
+          {
+            rounds ++;              
+          }
+          else
+          {
+            rounds = 0;
+            candidate = argmax;
+          }
+          if(rounds > 5)
+          {
+            rounds = 0;
+            active = candidate;
+          }
+      }           
+   }
+}