diff -r 69c2a1408619 -r a399f9d5e672 carrerashark/main.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/carrerashark/main.c	Fri Nov 18 12:16:22 2011 +0100
@@ -0,0 +1,160 @@
+#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;
+
+ISR ( INT0_vect ) {
+    writeBit(PORTD, 5, 1);
+    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
+    writeBit(PORTD, 5, 0);
+}
+
+
+ISR ( TIMER2_COMP_vect ) {
+    writeBit(PORTD, 4, 0);
+
+    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
+            data = bitbuf; // output data
+        } 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
+        }
+    }
+
+
+    writeBit(PORTD, 4, 1);
+}
+
+
+
+int main(void)
+{
+    uint8_t i;
+    unsigned char s[30];
+
+    // setup data bit timer
+    TCCR2 = (1<<CS21) | (1<<WGM21); //divide by 8, set compare match
+    OCR2 = TIMER2_50US;
+    TIMSK |= 1<<OCIE2; //enable timer2 interrupt
+
+    MCUCR = _BV(ISC00); // falling edge
+    GICR = _BV(INT0) ; // Enable INT0
+
+    writeBit(DDRD, 4, 1);
+    writeBit(DDRD, 5, 1);
+    writeBit(DDRD, 6, 1);
+
+
+    RS232_init(); // initialize RS232 interface
+    RS232_puts_p(PSTR("CarreraShark 1.0 - INIT OK\n"));
+    //RS232_puts_p(PSTR("Receiving one complete cycle:\n"));
+
+    sei();
+    i = 0;
+    while (1) {
+        // main loop
+
+        if (data != 0) {
+            if (data_len > 5) {
+                if (data_len == 13) { // sync to first packet
+                    i = 1;
+                    RS232_puts("\n");
+                } else if (i!=0) i++;
+                if (i>0) {
+                    itoa( data, s, 16);
+                    data = 0;
+                    RS232_puts("0x");
+                    RS232_puts( s );
+                    RS232_putc(' ');
+                }
+            }
+            //if (i==10) for (;;);
+        }
+    } // main loop end
+};
+