#include <OneButton.h>
OneButton wind_speed_pulse(A0, true); 
//library is te vinden op  http://www.mathertel.de/Arduino/OneButtonLibrary.aspx


double bearing,
       WindBearing,
       ref = 512,            //reference (180degrees) was 380
       sinus = 0,
       cosinus = 0,
       LastWindSpeed = 0,
       a = 0,
       previousPulseMillis = millis(),
       speedCompensation = 0;

unsigned long previousMillis_T1 = 0,previousMillis_T2 = 0;

String NMEAsentence = "";

void setup() 
{
  Serial.begin(9600);
  wind_speed_pulse.setClickTicks(10);
  wind_speed_pulse.attachClick(calc_wind_speed);
  
  
}

void loop() 
{
  getSettings();
  wind_speed_pulse.tick();     // check if wind sensor is activated
  get_WindBearing();
 
   if(millis() - previousMillis_T2 >= 500) 
    {
      if (a == LastWindSpeed) LastWindSpeed = 0; 
      previousMillis_T2 = millis();   
      /*      1 2 3 4 5
              | | | | |
      $--MWV,x.x,a,x.x,a*hh
      1) Wind Angle, 0 to 360 degrees
      2) Reference, R = Relative, T = True
      3) Wind Speed
      4) Wind Speed Units, K/M/N
      5) Status, A = Data Valid
      6) Checksum
      */
      NMEAsentence = "$WIMWV,"                        +               
                      String(WindBearing,2)           +
                      ",R,"                           + 
                      String(LastWindSpeed,2)         + 
                      ",N,A*"                         ;      
 
      Serial.print(NMEAsentence);
      Serial.println(getCheckSum(NMEAsentence),HEX);;
      a = LastWindSpeed;
    }  
}

void get_WindBearing()
{
  cosinus = analogRead(A1) - ref;
  sinus = analogRead(A2)  - ref;
  
  if (cosinus>0){
    WindBearing = 90-atan(sinus/cosinus)*(180/PI);
  }else if (cosinus<0){
    WindBearing = 270-atan(sinus/cosinus)*(180/PI);
  }else if (cosinus==0 & sinus<0){
    WindBearing = 180;
  }else{
    WindBearing = 0;
  }
  //WindBearing = 360 - WindBearing; indien omgedraaid moet worden
}



void calc_wind_speed()
{
  double pulse_time = millis() - previousPulseMillis ;
  previousPulseMillis = millis();
  LastWindSpeed = speedCompensation/pulse_time;
}


int getCheckSum(String s) 
{
  int i, XOR, c;

  for (XOR = 0, i = 0; i < s.length(); i++) 
  {
    c = (unsigned char)s.charAt(i);
    if (c == '*') break;
    if ((c!='$') && (c!='!')) XOR ^= c;
  }
  return XOR; 
}

void getSettings()
{
  ref = analogRead(A3);
  speedCompensation = analogRead(A4);
}