Files
pa50contr/uart.c
Олег Бородин c8f1609cf0 update
2024-08-21 12:30:07 +02:00

71 lines
1.7 KiB
C

/*
* Copyright 2017-2024 Oleg Borodin <onborodin@gmail.com>
*
*/
#include <stdio.h>
#include <stdbool.h>
#include <avr/io.h>
#include <util/delay.h>
#define BAUD 38400
#include <util/setbaud.h>
#include <tool.h>
#include <fifo.h>
#include <uart.h>
static uint8_t inbuf[FIFO_BUFFER_SIZE];
static uint8_t outbuf[FIFO_BUFFER_SIZE];
fifo_t uart_inbuf, uart_outbuf;
FILE uart_stream = FDEV_SETUP_STREAM(uart_putchar, uart_getchar, _FDEV_SETUP_RW);
int uart_putchar(char c, FILE * stream) {
return fifo_putc(&uart_outbuf, c);
}
int uart_getchar(FILE * stream) {
return (int)fifo_getc(&uart_inbuf);
}
void uartio_init(void) {
fifo_init(&uart_inbuf, inbuf, sizeof(inbuf));
fifo_init(&uart_outbuf, outbuf, sizeof(outbuf));
stdout = &uart_stream;
stdin = &uart_stream;
stderr = &uart_stream;
}
void uart_init(void) {
/* Set port speed */
UBRR0H = UBRRH_VALUE;
UBRR0L = UBRRL_VALUE;
/* Disable double speed operation */
REG_SETDOWN_BIT(UCSR0A, U2X0);
/* Set character size to 8 bit */
REG_SETDOWN_BIT(UCSR0B, UCSZ02);
REG_SETUP_BIT(UCSR0C, UCSZ01);
REG_SETUP_BIT(UCSR0C, UCSZ00);
/* Set one stop bit, no parity */
REG_SETDOWN_BIT(UCSR0C, USBS0);
REG_SETDOWN_BIT(UCSR0C, UPM00);
REG_SETDOWN_BIT(UCSR0C, UPM01);
/* Enable TX and RX */
REG_SETUP_BIT(UCSR0B, TXEN0);
REG_SETUP_BIT(UCSR0B, RXEN0);
/* Disable receive & transmit interrupts */
REG_SETDOWN_BIT(UCSR0B, RXCIE0);
REG_SETDOWN_BIT(UCSR0B, UDRIE0);
_delay_ms(20);
}
void uart_handle(void) {
volatile uint8_t xchar;
while ((xchar = fifo_getc(&uart_outbuf)) > 0) {
while (!REG_BIT_ISUP(UCSR0A, UDRE0));
UDR0 = xchar;
}
}