/*
 * Author: username
 * Date: 2024 
 * filename: usart.c
 * description: module_purpose
 */

#include "usart.h"
#include <avr/io.h>
#include <string.h>

#define F_CPU 3333333UL
#define F_PER F_CPU / 6
#define USART0_BAUD_RATE(BAUD_RATE) ((float)(F_PER * 64 / (16 * (float)BAUD_RATE)) + 0.5)

//RX PIN6, TX PIN7
//ALT: RX PIN12 TX PIN11
void USART0_init(void)
{
    //Config TxD as output, and rx as input?
    PORTB.DIR &= ~(1<<3);
    PORTB.DIR |= (1<<2);
    
    //setup Alternate pints on PA1 and PA2
    /*
    PORTMUX.CTRLB |= PORTMUX_USART0_ALTERNATE_gc;
    PORTA.DIRSET |= (1<<1);
    PORTA.DIRSET &= ~(1<<2);
    */

    //It says to set the TX pin high?
    //PORTB.OUT |= (1<<2);
    //PORTA.OUT |= (1<<11);

    //set buad rate.
    USART0.BAUD = (uint16_t)USART0_BAUD_RATE(9600);

    //set the frame format.
    USART0.CTRLC = 0x3;   //setting 8-bit mode.

    //Enable transmitter and receiver (USARTn.CTRLB)
    //USART0.CTRLB |= (1<<7)|(1<<6);
    USART0.CTRLB |= USART_TXEN_bm; 
}

void USART0_sendChar(char c)
{
    while (!(USART0.STATUS & USART_DREIF_bm)){
        ;
    }
    USART0.TXDATAL = c;
    USART0.TXDATAH = c;
}



void USART0_sendString(char *str)
{
    for(size_t i = 0; i < strlen(str); i++)
    {
        USART0_sendChar(str[i]);
    }
}