Sat, 03 Dec 2011 12:10:10 +0100
some code cleanup
#include <avr/interrupt.h> #include <avr/io.h> #include <avr/wdt.h> #include <avr/eeprom.h> #include <stdlib.h> #include <stdint.h> #include <avr/pgmspace.h> #include "main.h" #include "driver/rs232.h" #include "util/delay.h" static char buffer[RS232_BUFSIZE+1]; static uint8_t buffer_len; // USART0 RX interrupt ISR ( USART_RXC_vect ) { char c = UDR; // check for buffer overflow if (buffer_len==sizeof(buffer)) { buffer_len=0; if (c == 27) { // escape sequence, store to empty buffer buffer[buffer_len++] = c; } } else { // collect characters until end of line if (c == 27) { // escape sequence, clear buffer buffer_len = 0; buffer[buffer_len++] = c; } else if ( (c==0xff) && (buffer_len > 3) ) { buffer[buffer_len]=0; // packet end received, parse the received packet // wait for the next packet buffer_len=0; } else { buffer[buffer_len++]=c; } } } #define PULSE_PORT PORTD #define PULSE_BIT PD2 volatile uint16_t data = 0; volatile uint8_t data_len = 0; volatile uint8_t bitbuf_len = 0; volatile uint16_t bitbuf = 0; volatile uint16_t sysclock = 0; ISR ( TIMER0_OVF_vect ) { PORTD ^= _BV(PD6); if (sysclock != 0xffff) sysclock++; } ISR ( INT0_vect ) { PORTD ^= _BV(PD3); if (sysclock<10) { // this is the answer slot start bit?? PORTD ^= _BV(PD7); } else { GICR &= ~_BV(INT0) ; // Disable INT0 // Startsignal erkannt, ab hier den Timer2 starten, // der liest dann alle 50µs den Zustand ein und schreibt das // empfangene Bit in den Puffer bitbuf = 0; // init bitbuf_len = 0b10000000; // init 1 pulse received TCNT2 = 0; TIMSK |= _BV(OCIE2); //enable timer2 interrupt } } ISR ( TIMER2_COMP_vect ) { PORTD ^= _BV(PD4); uint8_t clock; uint8_t state; uint8_t state2; if ((bitbuf_len & 0b10000000) == 0) clock = 0; else clock = 0xff; if ((bitbuf_len & 0b01000000) == 0) state = 0; else state = 0xff; if ((PIN(PULSE_PORT) & _BV(PULSE_BIT)) == 0) state2 = 0; else state2 = 0xff; if (clock) { // second pulse of bit bitbuf_len &= ~_BV(7); // switch clock to low if ((state==state2) & state2) { // two cycles high: packet end received data_len = (bitbuf_len & 0b00111111); if (data_len == 13) PORTD ^= _BV(6); // debug sync output on program packets TIMSK &= ~_BV(OCIE2); //disable timer2 interrupt GICR |= _BV(INT0); // Enable INT0 GIFR &= ~_BV(INTF0); // clear int0 irq flag data = bitbuf; // output data sysclock = 0; // reset system clock counter } else { bitbuf_len++; // increment bit counter bitbuf = bitbuf << 1; // shift bits if (state2 == 0) bitbuf |= 1; // receive logic one } } else { // first pulse of bit bitbuf_len |= _BV(7); // switch clock to high if (state2) { bitbuf_len |= _BV(6); // store new state } else { bitbuf_len &= ~_BV(6); // store new state } } } int main(void) { uint8_t i; unsigned char s[10]; uint16_t tmp; uint16_t cycle[11]; // setup data bit timer TCCR2 = (1<<CS21) | (1<<WGM21); //divide by 8, set compare match OCR2 = TIMER2_50US; TIMSK |= 1<<OCIE2; //enable timer2 interrupt // setup system timer TCCR0 = (1<<CS21); //divide by 8 TIMSK |= 1<<TOIE0; //enable timer0 interrupt MCUCR = _BV(ISC00); // falling edge // MCUCR = _BV(ISC00) | _BV(ISC01); // rising edge GICR = _BV(INT0) ; // Enable INT0 DDRD |= _BV(PD3) | _BV(PD4) | _BV(PD5) | _BV(PD6) | _BV(PD7); PORTD |= _BV(PD7); RS232_init(); // initialize RS232 interface RS232_puts_p(PSTR("CarreraShark 1.2\n")); sei(); i = 0; while (1) { // main loop if (data != 0) { if (data_len > 5) { tmp = data; data = 0; if (data_len == 13) { // sync to first packet PORTD ^= _BV(PD5); for (i=0; i<10;i++ ) { // output previous cycle data itoa( cycle[i], s, 16); RS232_putc('0'); RS232_putc('x'); RS232_puts( s ); RS232_putc(' '); } RS232_putc('*'); i = 0; PORTD ^= _BV(PD5); } cycle[i] = tmp; i++; } //if (i==10) for (;;); } } // main loop end };