#include <stdint.h>
#include <stdbool.h>
#include "tm4c123gh6pm.h"

void GPIO_PORT_F_init(void)
{
    SYSCTL_RCGC2_R |= 0x00000020;             // ENABLE CLOCK TO GPIOF
    GPIO_PORTF_LOCK_R = 0x4C4F434B;           // UNLOCK COMMIT REGISTER
    GPIO_PORTF_CR_R   = 0x1F;                 // MAKE PORTF0 CONFIGURABLE
    GPIO_PORTF_DEN_R  = 0x1F;                 // SET PORTF DIGITAL ENABLE
    GPIO_PORTF_DIR_R  = 0x0E;                 // SET PF0, PF4 as input and PF1, PF2 and PF3 as output
    GPIO_PORTF_PUR_R  = 0x11;                 // PORTF PF0 and PF4 IS PULLED UP

    NVIC_EN0_R |= 1 << 30;
    GPIO_PORTF_IS_R  = 0x00;                  // EDGE SENSITIVE
    GPIO_PORTF_IBE_R = 0x00;                  // ONE EDGE
    GPIO_PORTF_IEV_R = 0x00;                  // INTERRUPT EVENT FALLING
    GPIO_PORTF_IM_R  |= 0x11;                 // UNMASK INTERRUPT
}

void GPIO_PORT_B_init(void)
{

    SYSCTL_RCGCGPIO_R |= 0x02;                // ENABLE CLOCK FOR GPIOB
    SYSCTL_RCGCUART_R |= 0x02;                // ENABLE CLOCK FOR UART1

    GPIO_PORTB_DEN_R |= 0x03;                 // DIGITAL ENABLE FOR PB0 AND PB1
    GPIO_PORTB_AFSEL_R |= 0x03;               // ENABLE ALTERNATE FUNCTION ON PB0,PB1

    GPIO_PORTB_PCTL_R = (GPIO_PORTB_PCTL_R & 0xFFFFFF00) | 0x00000011; // SET PB0, PB1 FOR UART FUNCTIONALITY

    UART1_CTL_R &= ~0x01;                     // DISABLE UART1 DURING SETUP
    UART1_IBRD_R = 104;                       // SET INTEGER PART OF BAUD RED FOR 9600 BAUD FORMULA:
    UART1_FBRD_R = 11;                        // SET FRACTIONAL PART OF BAUD RATE
    UART1_LCRH_R = 0x62;                      // SET 8-BIT, ODD PARITY, STOP BIT-1
    UART1_CC_R = 0x00;                        // USE SYSTEM CLOCK

    UART1_CTL_R |= 0x301;                     // ENABLE UART1, RX AND TX
}

void UART1_WRITE(char data)                   // UART1 WRITE DATA
{
    while (UART1_FR_R & 0x20);                // WAIT UNTIL TX FIFO IS NOT FULL
    UART1_DR_R = data;                        // WRITE DATA TO UART DATA REGISTER
}

char UART1_READ(void)                         // UART1 READ DATA
{
    while (UART1_FR_R & 0x10);                // WAIT UNTIL RX FIFO IS NOT EMPTY
    return (char)UART1_DR_R;                  // RETURN RECEIVED DATA
}

void UART1_RXTX_to_DISPLAY(char RX_DATA)
{
    if (RX_DATA == 0x52)
    {
    GPIO_PORTF_DATA_R |= 0x02;                // IF RECEIVED CHARACTER IS R TURN ON RED LED
    }
    else if (RX_DATA == 0x42)
    {
     GPIO_PORTF_DATA_R |= 0x04;               // IF RECEIVED CHARACTER IS B TURN ON BLUE LED
    }
    else if (RX_DATA == 0x47)
    {
     GPIO_PORTF_DATA_R |= 0x08;               // IF RECEIVED CHARACTER IS G TURN ON GREEN LED
    }
    else
    {
     GPIO_PORTF_DATA_R &= 0x00;               // RED LED FOR JUNK DATA
    }
    UART1_WRITE(RX_DATA);                     // SEND RECEIVED DATA TO DISPLAY
}


int main(void)                                // MAIN FUNCTION
{
    GPIO_PORT_F_init();                       // GPIO PORT F INITIALISATION FUNCTION
    GPIO_PORT_B_init();                       // GPIO PORT B INITIALISATION FUNCTION

    while (1)
    {
     UART1_RXTX_to_DISPLAY(UART1_READ());     // RECEIVE DATA, SEND RECEIVED DATA TO DISPLAY OR GLOW LED
    }
}