/* Copyright (c) 2007 The Information and Telecommunication Technology Center 
 * (ITTC) at the University of Kansas
 * ALL RIGHTS RESERVED
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License version 2 as
 *   published by the Free Software Foundation.
 *
 *   Alternatively, this software may be distributed under the terms of BSD
 *   license.
 *
 *
 * Function definitions for reading data from the Parallax Sensors
 *
 * %Notes
 * 
 * Author: Daniel Fokum, 20070529
 */
 /**
*
*   @file   Sensors.c
*
*   @brief  Function implementations for reading Parallax Sensors.
*
****************************************************************************/

/* ---- Include Files ---------------------------------------------------- */

#include <avr/io.h>
#include <util/delay.h>
#include <stdio.h>

#include "Hardware.h"
#include "Timer.h"
#include "Delay.h"
#include "Sensors.h"

/* ---- Public Variables -------------------------------------------------- */

/* ---- Private Constants and Types --------------------------------------- */

/* ---- Private Variables ------------------------------------------------- */

/* ---- Private Function Prototypes --------------------------------------- */

/* ---- Functions --------------------------------------------------------- */


//***************************************************************************
/**
 *  Reads data from the Parallax Ping Sensor
*/
uint8_t ReadPingSensor( uint8_t SensorIdx, uint16_t	Dist[] )
{
	unsigned int ticks=0;
	SENSOR_ON( PING1 );
	_delay_loop_1(26);		//Pause for 5 microseconds
	SENSOR_OFF( PING1 );
	DDRC = DDRC & (~(1<<PING1_SENSOR_PIN));	//Change data direction bit to input
	
	_delay_loop_2(2900);	//Pause for 725 microseconds
	/* Read port pins */
	while ((PINC & PING1_SENSOR_MASK) == 0x00)
		;
	TIM16_StartTCNT1();		//Start timer
	while ((PINC & PING1_SENSOR_MASK) == PING1_SENSOR_MASK)
		;
	TIM16_StopTCNT1();
	ticks = TIM16_ReadTCNT1();
	DDRC = DDRC | (1<<PING1_SENSOR_PIN);	//Change data direction bit to output
	
	// The next 6 lines are for debugging purposes.
	TIM16_StartTCNT1();
	_delay_loop_1(26);
	TIM16_StopTCNT1();
	ticks = TIM16_ReadTCNT1();
	Dist[SensorIdx] = ticks;
	
//	Dist[SensorIdx] = ticks*3/20;
	if (ticks==0)
		return 1;
	else
		return 0;
	/*
		//To return distance in inches do
			return(ticks*3/51);
		//To return distance in tenths of inches do
			return(ticks*3/5);
		//To return distance in centimeters do
			return(ticks*3/20);
		//To return distance in millimeters do
			return(ticks*3/2);	
	*/
}

//***************************************************************************
/**
 *  Reads data from the Parallax PIR (motion) Sensor
*/
uint8_t ReadPIRSensor( uint8_t SensorIdx, uint8_t Motion[] )
{
	//	Data direction bit is set to input in the InitHardware() function.
	LED_ON(YELLOW);
	if ((PINC & PIR1_SENSOR_MASK) == PIR1_SENSOR_MASK)
		Motion[SensorIdx] = 1;		//motion detected
	else
		Motion[SensorIdx] = 0;		//No motion detected
	LED_OFF(YELLOW);
	return 0;
}

/*
    To set bit n in a register to 1, do the following:
	DDRC = DDRC | (1<<n);
    To set bit n in a register to 0, do the following:
	DDRC = DDRC & (~(1<<n));
*/