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

//STAGE #1
//define pins
//add code here
int transistor = 2;
int hall_effect_sensor = A0;

//Sensor readings
//add code here
int hall_effect_sensor_volt = 0;
float pendulum_length = 0.30;
int hall_effect_val = 0;
/*--------------------------------------------  
-------- End Initialise Variables ----------
--------------------------------------------
*/


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

void setup() 
{

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

  //STAGE 2 - pin modes
  //add code here 
  pinMode(transistor, OUTPUT);
  pinMode(hall_effect_sensor, INPUT);
  //Control solenoid
  //add code here
  digitalWrite(transistor, LOW);
  delay(1000);
  digitalWrite(transistor, HIGH);
 delay(1000);
 digitalWrite(transistor, LOW);

}

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

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

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

  //get start time
  //add code here
startTime = millis();
  do  {
    
     //read Hall effects sensor
     //add code here
hall_effect_val = analogRead(hall_effect_sensor);

     //get current time
     //add code here
currentTime = millis();
     //calc elapsed time in milliseconds
     //add code here
	elapsedTime = (currentTime - startTime);
	 //Print data back to the computer
	 //add code here
	Serial.print("Elapsed time = ");
  Serial.print(elapsedTime);
  Serial.print(", Hall Effect = ");
  Serial.println(hall_effect_sensor);
  delay(1);
  } while (elapsedTime <= 10000);

  
  //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 ----------
----------------------------------
*/