uart.c

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#include "main.h"


void uart_init(void){


    //enable clock to GPIO, R1 = port B
    SYSCTL_RCGCGPIO_R |= SYSCTL_RCGCGPIO_R1;
    //enable clock to UART1, R1 = UART1. ***Must be done before setting Rx and Tx (See DataSheet)
    SYSCTL_RCGCUART_R |= SYSCTL_RCGCUART_R1;
    //enable alternate functions on port b pins 0 and 1
    GPIO_PORTB_AFSEL_R |= (BIT0 | BIT1);
    //enable Rx and Tx on port B on pins 0 and 1
    GPIO_PORTB_PCTL_R |= 0x00000011;
    //set pin 0 and 1 to digital
    GPIO_PORTB_DEN_R |= (BIT0 | BIT1);
    //set pin 0 to Rx or input
    GPIO_PORTB_DIR_R &= ~BIT0;
    //set pin 1 to Tx or output
    GPIO_PORTB_DIR_R |= BIT1;
    //calculate baudrate - 1152000, HSE should be 0, clkDiv = 16

    uint16_t iBRD = 0x8;
    uint16_t fBRD = 0x2c;
    //turn off uart1 while we set it up
    UART1_CTL_R &= ~(UART_CTL_UARTEN);
    //set baud rate
    UART1_IBRD_R = iBRD;
    UART1_FBRD_R = fBRD;
    //set frame, 8 data bits, 1 stop bit, no parity, no FIFO
    UART1_LCRH_R = UART_LCRH_WLEN_8;
    //use system clock as source
    UART1_CC_R = UART_CC_CS_SYSCLK;
    //re-enable enable RX, TX, and uart1
    UART1_CTL_R = (UART_CTL_RXE | UART_CTL_TXE | UART_CTL_UARTEN);
}

void uart_sendChar(char data){
    while(UART1_FR_R & 0x20) {} //wait to send
    UART1_DR_R = data;
}

int uart_receive(void){
    char data = 0;
    while(UART1_FR_R & UART_FR_RXFE) {} //wait 2 receive
    data = (char)(UART1_DR_R & 0xFF); //mask and get data bits

    return data; //return data
}

void uart_sendStr(const char *data) {
    char *i = data;
    while(*i != '\0') {     //move through string, sending it char by char
        uart_sendChar(*i);
        i++;
    }
}