--- a/receiver/main.c Fri Nov 18 08:42:24 2011 +0100
+++ b/receiver/main.c Fri Nov 18 12:03:07 2011 +0100
@@ -9,20 +9,12 @@
#include "main.h"
#include "driver/rs232.h"
-//#include "driver/manchester.h"
+#include "util/delay.h"
-volatile uint8_t datalen = 0;
-char data[10]; // 8 bytes data buffer + string termination
static char buffer[RS232_BUFSIZE+1];
static uint8_t buffer_len;
-volatile uint8_t bitbuf_len = 0;
-volatile uint16_t bitbuf = 0;
-volatile uint16_t bitbuf_out = 0;
-volatile uint8_t bitbuf_out_len = 0;
-volatile uint8_t timeout = 0;
-volatile uint8_t lastbit = 0;
@@ -57,172 +49,112 @@
}
-#define PULSE_IN PIND
-#define PULSE_BIT 2
+#define PULSE_PORT PORTD
+#define PULSE_BIT PD2
-#define TIMER_DIVISOR 8
-#define VALUE_100US 0.47e-4
-#define TIMER_100US 0xff - (uint8_t)(VALUE_100US * F_CPU/TIMER_DIVISOR)
+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(GICR, INT0, 0); // disable INT0 interrupt
- // Startsignal erkannt, ab hier den Timer0 starten,
- // der liest dann alle 100µs den Zustand ein und schreibt das
+ 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
- lastbit = 0b10000001; // initialize
-
- TCNT0 = TIMER_100US;
- TIMSK |= 1<<TOIE0; //enable timer0 interrupt
+ bitbuf = 0; // init
+ bitbuf_len = 0b10000000; // init 1 pulse received
+ TCNT2 = 0;
+ TIMSK |= _BV(OCIE2); //enable timer2 interrupt
+ writeBit(PORTD, 5, 0);
}
-ISR ( TIMER0_OVF_vect ) {
- uint8_t sr = SREG;
- TCNT0 = TIMER_100US; // reset timer for next bit time
+
+ISR ( TIMER2_COMP_vect ) {
writeBit(PORTD, 4, 0);
- // read the current bit value, store it to 16bit buffer
- if ( (PULSE_IN & _BV(PULSE_BIT)) == 0 ) {
-//RS232_putc('L');
+
+ 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 ( (lastbit & 1) == 1) {
- // bit cleared, second block
- // insert bit
- bitbuf |= 1;
- bitbuf = bitbuf << 1;
- bitbuf_len++;
- lastbit = 0; // set block number0 & signal state to 0
+ 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 {
- // bit cleared, first block
- lastbit = 1; // set block number1 & signal state to 0
+ bitbuf_len++; // increment bit counter
+ bitbuf = bitbuf << 1; // shift bits
+ if (state2 == 0) bitbuf |= 1; // receive logic one
}
} else {
-//RS232_putc('H');
- if ( (lastbit & 1) == 1) {
- // bit set, second block
- if ( (lastbit & _BV(7)) == 0) {
- // insert zero bit
- bitbuf = bitbuf << 1;
- bitbuf_len++;
- lastbit = 0b10000000; // set block number0 & signal state to 1
- } else {
- // no change, transmission END!
- lastbit = 0xff;
- }
+ // first pulse of bit
+ bitbuf_len |= _BV(7); // switch clock to high
+ if (state2) {
+ bitbuf_len |= _BV(6); // store new state
} else {
- // bit set, first block
- lastbit = 0b10000001; // set block number1 & signal state to 1
+ bitbuf_len &= ~_BV(6); // store new state
}
}
- if ( (bitbuf_len == 16) | (lastbit == 0xFF) ) {
- // 16 bits full or transmission end
- // export to uart
- writeBit(TIMSK, TOIE0, 0); // disable timer0 interrupt
- if (bitbuf > 0) {
- bitbuf_out = bitbuf;
- bitbuf_out_len = bitbuf_len;
- }
- bitbuf = 0;
- bitbuf_len = 0;
- GICR |= _BV(INT0); // Enable INT0
- }
+
writeBit(PORTD, 4, 1);
- SREG = sr;
-}
-
-volatile uint16_t pulse_counter = 0;
-volatile uint8_t measure_progress = 0;
-volatile uint16_t car_id = 0;
-ISR(TIMER2_OVF_vect) {
- TCNT2 = 0xF5;
- pulse_counter++;
}
-ISR (INT1_vect) {
- // measure pulse width
- //RS232_putc('x');
- if (measure_progress == 0) {
- // start measuring
- TCNT2 = 0xF5;
- pulse_counter = 0;
- measure_progress = 1;
- // set INT1 to rising edge (stops current measurement)
- //MCUCR |= _BV(ISC10);
- writeBit(PORTD, 4, 1);
- } else {
- // stop measuring
- car_id = pulse_counter;
- measure_progress = 0;
- // set INT1 to falling edge (initiates next measurement)
- //MCUCR &= ~_BV(ISC10);
- writeBit(PORTD, 4, 0);
- }
-}
int main(void)
{
- uint i;
-char s[30];
-
- TCCR0 = 0; //timer off
- //TCCR0 = (1<<CS00); //divide by 1
- TCCR0 = (1<<CS01); //divide by 8
- //TCCR0 = (1<<CS01) | (1<<CS00); //divide by 64
- //TCCR0 = (1<<CS02); //divide by 256
- //TCCR0 = (1<<CS02) | (1<<CS00); //divide by 1024
+ uint8_t i;
+ unsigned char s[30];
- //TIMSK = 1<<TOIE0; //enable timer interrupt
- // Timer will be enabled on INT0
+ // setup data bit timer
+ TCCR2 = (1<<CS21) | (1<<WGM21); //divide by 8, set compare match
+ OCR2 = TIMER2_50US;
+ TIMSK |= 1<<OCIE2; //enable timer2 interrupt
- // configure timer2 for pulse measurement
- //TCCR2 = (1<<CS21); // divide 8
- TCCR2 = (1<<CS20); // divide 1
- TIMSK = 1<<TOIE2;
-
- // configure INT0+1 for falling edge
- // INT2 on every edge
- //MCUCR = _BV(ISC00) | _BV(ISC11);
- MCUCR = _BV(ISC11);
-// GICR = _BV(INT0) | _BV(INT1) ; // Enable INT0/1
- GICR = _BV(INT1) ; // Enable INT1
+ 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("INIT OK\n"));
+ RS232_puts_p(PSTR("CarreraShark 1.0 - INIT OK\n"));
+ //RS232_puts_p(PSTR("Receiving one complete cycle:\n"));
+ sei();
i = 0;
-
- sei();
while (1) {
// main loop
- if (car_id != 0) {
- itoa( car_id, s, 10);
- car_id = 0;
- RS232_puts( s );
- RS232_putc('\n');
-
+ 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 (;;);
}
- /*cli();
- i = rc5_data; // read two bytes from interrupt !
- rc5_data = 0;
- sei();
- if (i) {
- itoa( i, s, 10);
- RS232_puts( s );
- } */
-/*
- if (p_len < 0xFF) p_len++;
- if( (p_bit ^ PULSE_IN) & 1<<PULSE_BIT ){ // change detect
- p_bit = ~p_bit; // 0x00 -> 0xFF -> 0x00
- itoa( p_len, s, 10);
- RS232_puts(s);
- RS232_puts_p(PSTR("\n"));
- p_len = 0;
- }
-*/
} // main loop end
};
