jens
54ac3a2834
git-svn-id: http://moon:8086/svn/projects/HendiControl@164 fda53097-d464-4ada-af97-ba876c37ca34
101 lines
1.5 KiB
C
101 lines
1.5 KiB
C
/*
|
|
* uart.c
|
|
*
|
|
* Created: 20.02.2019 20:50:13
|
|
* Author: jens
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <avr/io.h>
|
|
|
|
#include "uart.h"
|
|
|
|
void uart_init(uint32_t baudrate)
|
|
{
|
|
uint16_t prescale8 = UART_PRESCALE(baudrate, 8UL);
|
|
uint16_t prescale16 = UART_PRESCALE(baudrate, 16UL);
|
|
|
|
uint32_t baud8 = ((prescale8+1) * 8);
|
|
uint32_t baud16 = ((prescale16+1) * 16);
|
|
|
|
uint32_t err8 = abs(baudrate - baud8);
|
|
uint32_t err16 = abs(baudrate - baud16);
|
|
|
|
uint16_t prescale = prescale16;
|
|
if (err8 < err16)
|
|
{
|
|
prescale = prescale8;
|
|
|
|
// Double UART speed
|
|
UCSR0A |= 1 << U2X0;
|
|
}
|
|
|
|
// Set baud rate
|
|
UBRR0L = (uint8_t)prescale;
|
|
UBRR0H = (uint8_t)(prescale >> 8);
|
|
|
|
// Enable receiver and transmitter
|
|
UCSR0B = (1<<TXEN0)|(1<<RXEN0);
|
|
}
|
|
|
|
void uart_putc(char c)
|
|
{
|
|
while((UCSR0A & (1<<UDRE0)) == 0)
|
|
{
|
|
}
|
|
UDR0 = c;
|
|
}
|
|
|
|
char uart_getc()
|
|
{
|
|
while ((UCSR0A & (1 << RXC0)) == 0)
|
|
{
|
|
}
|
|
return UDR0;
|
|
}
|
|
|
|
void uart_puts(char const *str)
|
|
{
|
|
while(*str)
|
|
{
|
|
char c = *(str++);
|
|
uart_putc(c);
|
|
if (c == 0x0A)
|
|
{
|
|
uart_putc(0x0D);
|
|
}
|
|
}
|
|
}
|
|
|
|
void print_byte(char byte)
|
|
{
|
|
int i;
|
|
unsigned char c, nibble;
|
|
|
|
for (i=0; i < 2; i++)
|
|
{
|
|
nibble = (char)((byte >> 4) & 0xF);
|
|
byte <<= 4;
|
|
|
|
if (nibble < 10)
|
|
c = nibble + '0';
|
|
else
|
|
c = nibble + 'A' - 10;
|
|
|
|
uart_putc(c);
|
|
}
|
|
}
|
|
|
|
void print_word(uint16_t word)
|
|
{
|
|
int i;
|
|
unsigned char c;
|
|
|
|
for (i=0; i < 2; i++)
|
|
{
|
|
c = (char) (word >> 8);
|
|
print_byte(c);
|
|
word <<= 8;
|
|
}
|
|
}
|