////////////////////////////////////////////////////////////////////////////////////////////////////
//Title: HCSR04
//Author: Austin Matthew
//Purpose: supply arduino sketch with simple library that includes functionallity for HCSR04 sensor
////////////////////////////////////////////////////////////////////////////////////////////////////




#ifndef HCSR04_h //defining class header
#define HCSR04_h



#include "Arduino.h" //importing base arduino library. needed for pinValue and PulseIn

//******************************************************************************************************************************************************
//Defining certain parts of the class here.  Also giving class name
//******************************************************************************************************************************************************

class HCSR04ProxSensor
{
  public:                                         // the public section is for things that can be used by other parts of the program

    HCSR04ProxSensor(int echoPin,int triggerPin); // defining the constructor and its arguments

    float readSensor(int range);                           // placing required methods into class header
    float getLastValue();
    float lastValue;                              // placing public variables that can be read/written to by more than just one method.
    float currentValue;


  private:                                        // placing variables in private such that no other
                                                  //aspect of the program can change them. also useful if more than one object of the same
                                                  // kind if constructed.
    int _echoPin;
    int _triggerPin;
    
    
};

#endif


//******************************************************************************************************************************************************
//actual workings/definitions of functions stated in header file
//******************************************************************************************************************************************************

HCSR04ProxSensor::HCSR04ProxSensor(int echoPin,int triggerPin) //constructor
{
  _echoPin = echoPin;                                          // giving object its own set of pins.
  _triggerPin = triggerPin;
  lastValue=0;                                                 //last and current values are brought in for comparison function.
  currentValue=0;

}
 float HCSR04ProxSensor::readSensor(int range)                          //complete setup of URM including pin modes, and timing
 {
  //   pinMode(_triggerPin, OUTPUT);  
     pinMode(_triggerPin,LOW);                                 // high/lows for ping generation and reading
     delayMicroseconds(2);
     pinMode(_triggerPin,HIGH);
     delayMicroseconds(2);
     digitalWrite(_triggerPin, LOW);
   //  pinMode(_triggerPin, INPUT);  
      
     float duration=pulseIn(_echoPin,HIGH);
     delay(5);                                              // 1 second delay for more manageable reading
     duration= duration/29/2;                                  // converting time to distance, and cutting it in half, because math.
    if(duration > range)
    {
     currentValue=range;   
    }
    else{currentValue=duration;}
    
   
     

     return currentValue;
 }

 float HCSR04ProxSensor::getLastValue()
 {
                                                               // i dont know enough words to explain the complexity of this function. god help us all.
     return lastValue;
 }