pentabug/firmware/usart.c

137 lines
2.9 KiB
C

/*
* PentaFnord Firmware
*
* by Alexander Lorz <bigalex@gmx.de>
*
*
* The USART control code is derived by code from the 4CHLED project
* by sebseb7: https://github.com/sebseb7/eagle/tree/master/4CHLED/firmware
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <avr/io.h>
#include <avr/interrupt.h>
//#include "main.h"
#include "usart.h"
#define UART_RXBUFSIZE 32
volatile static uint8_t rxbuf0[UART_RXBUFSIZE];
volatile static uint8_t *volatile rxhead0, *volatile rxtail0;
//volatile uint8_t xon = 0;
ISR (USART_RX_vect)
{
UCSR0B &= ~(1 << RXCIE0);
asm volatile("sei");
int diff;
uint8_t c;
c=UDR0;
diff = rxhead0 - rxtail0;
if (diff < 0) diff += UART_RXBUFSIZE;
if (diff < UART_RXBUFSIZE -1)
{
*rxhead0 = c;
++rxhead0;
if (rxhead0 == (rxbuf0 + UART_RXBUFSIZE)) rxhead0 = rxbuf0;
// if((diff > 100)&&(xon==0))
// {
// xon=1;
// //set the CTS pin
// }
}
UCSR0B |= (1 << RXCIE0);
}
void USART0_Init (void)
{
// set baudrate
#undef BAUD
#define BAUD 115200
#include <util/setbaud.h><util/setbaud.h>
UBRR0H = UBRRH_VALUE;
UBRR0L = UBRRL_VALUE;
//#if USE_2X
UCSR0A |= (1 << U2X0); // enable double speed operation
//#else
// UCSR0A &= ~(1 << U2X0); // disable double speed operation
//#endif
// flush receive buffer
while ( UCSR0A & (1 << RXC0) ) UDR0;
// set 8N1
UCSR0C = (1 << UCSZ01) | (1 << UCSZ00);
UCSR0B &= ~(1 << UCSZ02);
UCSR0B |= (1 << RXEN0)|(1 << TXEN0); //enable send and receive
UCSR0B |= (1 << RXCIE0); //enable receive interrup
rxhead0 = rxtail0 = rxbuf0;
}
void USART0_putc (char c)
{
loop_until_bit_is_set(UCSR0A, UDRE0);
UDR0 = c;
}
uint8_t USART0_Getc_nb(uint8_t *c)
{
if (rxhead0==rxtail0) return 0;
*c = *rxtail0;
if (++rxtail0 == (rxbuf0 + UART_RXBUFSIZE)) rxtail0 = rxbuf0;
// uint8_t diff = rxhead0 - rxtail0;
// if((diff < 10)&&(xon==1))
// {
// xon=0;
// //set the CTS pin
// }
return 1;
}
void USART0_crlf(){
USART0_putc(0x0A); //newline
USART0_putc(0x0D); //carriage return
};
void USART0_put_uint8(uint8_t x){
uint8_t highchar=((x & 0b11110000)>>4)+0x30;
uint8_t lowchar = (x & 0b00001111)+0x30;
highchar = highchar>0x39 ? highchar + 0x07 : highchar; //chars A to F start with 0x41 not 0x3A
lowchar = lowchar>0x39 ? lowchar + 0x07 : lowchar;
USART0_putc(highchar);
USART0_putc(lowchar);
}
void USART0_put_uint16(uint16_t x){
USART0_put_uint8 ((x & 0xFF00)>>8);
USART0_put_uint8 (x & 0x00FF);
}