/*
 * Ultra_Sensor.c
 *
 *  Created on: Mar 3, 2017
 *      Author: tyborch
 */
#include <stdbool.h>
#include <stdio.h>
#include "lcd.h"
#include "Timer.h"
#include "driverlib/interrupt.h"
volatile unsigned rise, fall, intCount;
int overflow;
void Timer_Interrupt(void);
void TimerInit() { //Using input edge timing
    SYSCTL_RCGCTIMER_R |= SYSCTL_RCGCTIMER_R3;
    TIMER3_CTL_R &= ~(TIMER_CTL_TAEN | TIMER_CTL_TBEN); //Disables timer B
    TIMER3_CTL_R |= 0x00000C00; //Trigger on both edges
    TIMER3_CFG_R |= TIMER_CFG_16_BIT;
    TIMER3_TBMR_R |= 0x00000017; //
    TIMER3_TBILR_R = 0xFFFF; //set upper bound here
    TIMER3_ICR_R = (TIMER_ICR_CBECINT | TIMER_ICR_CAECINT); //Clears the timer B capture event interrupt
    TIMER3_IMR_R |= (TIMER_IMR_CBEIM | TIMER_IMR_CAEIM); //Enables the timer capture event interrupts
    NVIC_EN1_R = 0x00000018; //bits 35 and 36
    IntMasterEnable();
    TIMER3_CTL_R |= (TIMER_CTL_TAEN | TIMER_CTL_TBEN); //Enables timer

}
void Timer_Interrupt(void) {
    TIMER3_ICR_R |= TIMER_RIS_CBERIS;
    if (intCount % 2 == 0){
        rise = TIMER3_TBR_R;
    }
    else {
        fall = TIMER3_TBR_R;
    }
    intCount++;
}
void sensorInit() {
    SYSCTL_RCGCGPIO_R |= SYSCTL_RCGCGPIO_R1;
    GPIO_PORTB_DEN_R |= 0x08;
    GPIO_PORTB_DIR_R |= 0x08;
}
void sendPulse() { //Sending the pulse
    GPIO_PORTB_AFSEL_R &= 0xF7; //Disables alternate function for p3
    GPIO_PORTB_DIR_R |= 0x08; //Sets portB to output
    GPIO_PORTB_DATA_R |= 0x08; //Sets PB3 to high
    timer_waitMicros(7);
    GPIO_PORTB_DATA_R &= 0xF7; //Sets PB3 to low
    GPIO_PORTB_DIR_R &= 0xF7; //Sets portB to input
    GPIO_PORTB_AFSEL_R |= 0x08; //Enables alternate function for p3
    GPIO_PORTB_PCTL_R |= 0x7000; //CHOOSES what function to use.
    timer_waitMillis(50);
}
double redistance(int time) {
    double t = 0.00225*(time/2);
    return t;
}
unsigned int get_time() {
    sendPulse();
    int time = fall - rise;
    if(time < 0) {
        overflow++;
    }
    timer_waitMillis(200);
    double dist = redistance(time);
    lcd_printf("%d ms \n%.2f cm\nOverflow: %d", time/1000, dist, overflow);
    return time;
}
int main() {
    lcd_init();
    TimerInit();
    sensorInit();
    overflow = 0;
    IntRegister(INT_TIMER3B, Timer_Interrupt);
    while (1) {
        get_time();
    }
}