119 lines
2.7 KiB
C
119 lines
2.7 KiB
C
/*
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* PentaFnord Firmware
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*
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* by Alexander Lorz <bigalex@gmx.de>
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*
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*
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* The USART control code is derived by code from the 4CHLED project
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* by sebseb7: https://github.com/sebseb7/eagle/tree/master/4CHLED/firmware
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*
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* This program is free software: you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 3 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include "usart.h"
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#define UART_RXBUFSIZE 32
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static volatile uint8_t rxbuf0[UART_RXBUFSIZE];
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static volatile uint8_t * volatile rxhead0, * volatile rxtail0;
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ISR (USART_RX_vect) {
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UCSR0B &= ~(1 << RXCIE0);
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asm volatile("sei");
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int diff;
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uint8_t c;
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c = UDR0;
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diff = rxhead0 - rxtail0;
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if (diff < 0)
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diff += UART_RXBUFSIZE;
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if (diff < UART_RXBUFSIZE - 1) {
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*rxhead0 = c;
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++rxhead0;
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if (rxhead0 == (rxbuf0 + UART_RXBUFSIZE))
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rxhead0 = rxbuf0;
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}
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UCSR0B |= (1 << RXCIE0);
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}
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void USART0_Init(void) {
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// set baudrate
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#define BAUD_TOL 4
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#undef BAUD
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#define BAUD 115200
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#include <util/setbaud.h>
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UBRR0H = UBRRH_VALUE;
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UBRR0L = UBRRL_VALUE;
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#if USE_2X
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UCSR0A |= (1 << U2X0); // enable double speed operation
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#else
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UCSR0A &= ~(1 << U2X0); // disable double speed operation
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#endif
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// flush receive buffer
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while (UCSR0A & (1 << RXC0))
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UDR0;
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// set 8N1
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UCSR0C = (1 << UCSZ01) | (1 << UCSZ00);
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UCSR0B &= ~(1 << UCSZ02);
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UCSR0B |= (1 << RXEN0) | (1 << TXEN0); //enable send and receive
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UCSR0B |= (1 << RXCIE0); //enable receive interrup
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rxhead0 = rxtail0 = rxbuf0;
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}
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void USART0_putc(char c) {
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loop_until_bit_is_set(UCSR0A, UDRE0);
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UDR0 = c;
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}
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uint8_t USART0_Getc_nb(uint8_t *c) {
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if (rxhead0 == rxtail0)
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return 0;
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*c = *rxtail0;
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if (++rxtail0 == (rxbuf0 + UART_RXBUFSIZE))
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rxtail0 = rxbuf0;
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return 1;
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}
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void USART0_crlf(void) {
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USART0_putc(0x0A); //newline
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USART0_putc(0x0D); //carriage return
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}
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;
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void USART0_put_uint8(uint8_t x) {
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uint8_t highchar = ((x & 0b11110000) >> 4) + 0x30;
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uint8_t lowchar = (x & 0b00001111) + 0x30;
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highchar = highchar > 0x39 ? highchar + 0x07 : highchar; //chars A to F start with 0x41 not 0x3A
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lowchar = lowchar > 0x39 ? lowchar + 0x07 : lowchar;
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USART0_putc(highchar);
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USART0_putc(lowchar);
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}
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void USART0_put_uint16(uint16_t x) {
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USART0_put_uint8((x & 0xFF00) >> 8);
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USART0_put_uint8(x & 0x00FF);
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}
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