/*
 * Phase Offset Detection Example Code
 * Written by Matthew Bon for Digikey Electronics
 */

#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_nvic.h"
#include "inc/hw_types.h"
#include "inc/hw_gpio.h"
#include "driverlib/sysctl.h"
#include "driverlib/interrupt.h"
#include "driverlib/systick.h"
#include "driverlib/rom.h"
#include "driverlib/pin_map.h"
#include "driverlib/uart.h"
#include "grlib/grlib.h"
#include "utils/uartstdio.h"
#include "driverlib/gpio.h"
#include "driverlib/gpio.c"
#include "driverlib/timer.h"


uint32_t DeltaT = 0;
uint32_t Phase_offset = 0;
int status = 0;


/*Check if Driver Library Encounters an error */
#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif

/*Functions*/
extern void IntHandler_Phase(void);
void System_Init();


void IntHandler_Phase()
{
	//Clear Interrupt
	status = GPIOIntStatus(GPIO_PORTC_BASE,true);
	GPIOIntClear(GPIO_PORTC_BASE,status);


		if (GPIOPinRead(GPIO_PORTC_BASE, GPIO_PIN_7) == 128) //Check if it was a rising edge.
		{
			TimerEnable(TIMER0_BASE, TIMER_A); //If it was a rising edge, start timer.

		}

		else //If falling edge, perform measurment.
		{

			/*Calculate DeltaT*/
			DeltaT = (65535 - TimerValueGet(TIMER0_BASE, TIMER_A));
			/*Calculate Phase Offset, Hard Coded for a 60 Hz signal  T = 16.67 ms, 1 timer count = 0.32 us, Thus the period = 52083 counts */
			Phase_offset = (((DeltaT * 100000)/(52083)) * 360 )/10000;

			/*Reset and Reload Timer*/
			TimerDisable(TIMER0_BASE, TIMER_A);
			SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
			TimerConfigure(TIMER0_BASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_ONE_SHOT);
			TimerLoadSet(TIMER0_BASE, TIMER_A, 65535);

		}


}


//*****************************************************************************
//
// Configure the UART
//
//*****************************************************************************
void
Configure_UART(void)
{
	/*Enable GPIO and UART*/
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);

    /*Configure GPIO A0 and A1 as UARTS*/
    ROM_GPIOPinConfigure(GPIO_PA0_U0RX);
    ROM_GPIOPinConfigure(GPIO_PA1_U0TX);
    ROM_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);

    /*Designate UART Clock Source*/
    UARTClockSourceSet(UART0_BASE, UART_CLOCK_SYSTEM);

    UARTStdioConfig(0, 115200, 3125000);
}


//*****************************************************************************
//
//Initiate System, wait for interrupts and print out phase offset value
//
//*****************************************************************************
int main(void)
{


     System_Init();

	 while(1)
	 {

			 UARTprintf("Phase offset = %i \n", Phase_offset); // Display three significant figures..aka..a phase offset of 89.2 will be printed as 892

	 }


}

void System_Init()
{
		SysCtlClockSet(SYSCTL_SYSDIV_64 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ |
			                       SYSCTL_OSC_MAIN); //  200 MHz / sysdiv = 3.125 MHZ

		/*Init Port C*/
		SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);
		SysCtlDelay(3);

		GPIOPinTypeGPIOInput(GPIO_PORTC_BASE, GPIO_INT_PIN_7);
		GPIOPadConfigSet(GPIO_PORTC_BASE ,GPIO_INT_PIN_7,GPIO_STRENGTH_2MA,GPIO_PIN_TYPE_STD_WPD);
		GPIOIntTypeSet(GPIO_PORTC_BASE,GPIO_PIN_7,GPIO_BOTH_EDGES); //Set Interrupt Type on PORT C, pin 7


		/*Register Interrupt*/
		GPIOIntRegister(GPIO_PORTC_BASE,IntHandler_Phase);


		/*Configure UART */
		Configure_UART();

		/*Configure Timer*/

		SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);


		TimerConfigure(TIMER0_BASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_ONE_SHOT);


		TimerLoadSet(TIMER0_BASE, TIMER_A, 65535);


		IntPrioritySet(INT_GPIOC_TM4C123, 0); //Set Interrupt at highest priority.

		/*Enable Interrupt*/
		GPIOIntEnable(GPIO_PORTC_BASE, GPIO_INT_PIN_7);


}