/* 
--------------------------------------------  
-------- Begin Initialise Variables --------
--------------------------------------------
*/

//STAGE #1
//define pins
int Transistorpin = 2;
int Hall_EffectSensor = A0;
bool Solenoid_val = false;
int Hall_EffectSensorValue = 0;
float Pendulum_length = 0.3;

//Sensor readings


/*--------------------------------------------  
-------- End Initialise Variables ----------
--------------------------------------------
*/


/* 
----------------------------------  
-------- Begin Setup Loop --------
----------------------------------
*/

void setup() 
{
  pinMode(Hall_EffectSensor, INPUT);
  pinMode(Transistorpin, OUTPUT);

  // initialize serial communication at 115200 bits per second.
  Serial.begin(9600);

  //STAGE 2 - pin modes
  pinMode(A0, INPUT);
  pinMode(2, OUTPUT);
  
  //Control solenoid
  digitalWrite(2, LOW);
  digitalWrite(2, HIGH);
  delay(500);
  digitalWrite(2, LOW);
}

/* 
-------------------------------
------- End Setup Loop --------
-------------------------------
*/

/* 
----------------------------------  
-------- Begin Main Loop ---------
----------------------------------
*/ 

  //STAGE 3 - the main loop
void loop() 
{
  // variables for timing
  unsigned long startTime = 0;
  unsigned long currentTime = 0;
  unsigned long elapsedTime = 0;

  //get start time
  currentTime = millis();

  do  {
    
     //read Hall effects sensor
     Hall_EffectSensorValue = analogRead(A0);


     //get current time
     currentTime = millis();

     //calc elapsed time in milliseconds
     elapsedTime = currentTime - startTime;
	
	 //Print data back to the computer
	 Serial.print("Hall_EffectSensorValue = ");
   Serial.println(Hall_EffectSensorValue);
   Serial.println("Elapsed time = ");
   Serial.println(elapsedTime);

	
  } while (elapsedTime < 1000);

  
  //STAGE 5 - calculate Gravity...
  //average_period = something here;

  //evaluate gravity
  //g = your calculation here: use the sq() and PI

  //STAGE 5b - print your answer...
  Serial.print("gravity = ");
  
  delay(10000); //wait for 10 seconds - LEAVE THIS FOR RELOAD TO WORK PROPERLY!
}

/* 
----------------------------------  
--------- End Main Loop ----------
----------------------------------
*/