51 lines
1.2 KiB
C
51 lines
1.2 KiB
C
//uart2.c
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#include "uart2.h"
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include <avr/pgmspace.h>
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#include "rbuf.h"
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#include "macros.h"
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#define UART_BAUD_SELECT(baudRate,xtalCpu) (((float)(xtalCpu))/(((float)(baudRate))*8.0)-1.0+0.5)
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#define uart2_txready (UCSR2A & (1 << UDRE2))
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uint8_t uart2_ibuf[20] = {0, 0};
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FILE _uart2io = {0};
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static int uart2_putchar(char c, _UNUSED FILE *stream)
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{
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while (!uart2_txready);
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UDR2 = c; // transmit byte
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return 0;
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}
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static int uart2_getchar(_UNUSED FILE *stream)
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{
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if (rbuf_empty(uart2_ibuf)) return -1;
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return rbuf_get(uart2_ibuf);
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}
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//uart init (io + FILE stream)
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void uart2_init(uint32_t baudRate)
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{
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DDRH &= ~0x01;
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PORTH |= 0x01;
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rbuf_ini(uart2_ibuf, sizeof(uart2_ibuf) - 4);
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UCSR2A |= (1 << U2X2); // baudrate multiplier
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UBRR2L = UART_BAUD_SELECT(baudRate, F_CPU); // select baudrate
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UCSR2B = (1 << RXEN2) | (1 << TXEN2); // enable receiver and transmitter
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UCSR2B |= (1 << RXCIE2); // enable rx interrupt
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fdev_setup_stream(uart2io, uart2_putchar, uart2_getchar, _FDEV_SETUP_WRITE | _FDEV_SETUP_READ); //setup uart2 i/o stream
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}
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ISR(USART2_RX_vect)
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{
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if (rbuf_put(uart2_ibuf, UDR2) < 0) // put received byte to buffer
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{ //rx buffer full
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puts_P(PSTR("USART2 rx Full!!!"));
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}
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}
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