//#define NO_MODULATION
#define WAIT_LASER
-#define MODUL_455KHZ
-//#define MODUL_56KHZ
+//#define MODUL_455KHZ
+#define MODUL_56KHZ
//#define MODUL_38KHZ
-//#define SPEED_40RPS
+//#define INC_FRAME
+//#define FIXED_FRAME
+//#define SEND_RAWTIME
+#define LOCK_BUS
#define SPEED_20RPS
-//#define SPEED_10RPS
/* beacon identifier: must be odd, 3 bits */
#define BEACON_ID 0x1
#define IR_DDR DDRB
#define IR_BIT 1
+#define LOCKBUS_PORT PORTD
+#define LOCKBUS_PIN PIND
+#define LOCKBUS_DDR DDRD
+#define LOCKBUS_BIT 3
+
/* FRAME must be odd */
/* #define FRAME 0x0B /\* in little endian 1-1-0-1 *\/ */
/* #define FRAME_LEN 4 */
-#define FRAME 0x4A5B /* in little endian */
+#define FRAME 0x621 /* in little endian */
#define FRAME_LEN 16
/* pin returns !0 when nothing, and 0 when laser is on photodiode */
#define PHOTO_BIT 0
#define READ_PHOTO() (!!(PHOTO_PIN & (_BV(PHOTO_BIT))))
-/* IR_DELAY **must** be < 32768 */
-#if (defined SPEED_10RPS)
-#define MIN_INTER_TIME ((uint16_t)(160*2)) /* t~=160us dist=350cm */
-#define MAX_INTER_TIME ((uint16_t)(8000*2)) /* t=8ms dist=10cm */
-#define IR_DELAY ((uint16_t)(8000*2))
-#define INTER_LASER_TIME 30 /* in ms */
-#elif (defined SPEED_20RPS)
-#define MIN_INTER_TIME ((uint16_t)(40*16)) /* t~=80us dist=350cm */
-#define MAX_INTER_TIME ((uint16_t)(2000*16)) /* t=2ms dist=? >10cm */
-#define IR_DELAY ((uint16_t)(2000*16))
-#define INTER_LASER_TIME 10 /* in ms */
-#elif (defined SPEED_40RPS)
-#define MIN_INTER_TIME ((uint16_t)(40*16)) /* t~=40us dist=350cm */
-#define MAX_INTER_TIME ((uint16_t)(2000*16)) /* t=2ms dist=10cm */
-#define IR_DELAY ((uint16_t)(2000*16))
+/* IR_DELAY must be < 32768 */
+#define MIN_INTER_TIME ((uint16_t)(100*16U)) /* t~=160us dist=400cm */
+#define MAX_INTER_TIME ((uint16_t)(4000*16U)) /* t=4ms dist=16cm */
+#define IR_DELAY ((uint16_t)(MAX_INTER_TIME/2))
#define INTER_LASER_TIME 10 /* in ms */
-#else
-#error "speed not defined"
-#endif
extern prog_uint16_t framedist_table[];
/* basic functions to transmit on IR */
xmit_0();
}
-#ifdef WAIT_LASER
/* val is 12 bits. Return the 16 bits value that includes the 4 bits
* cksum in MSB. */
static uint16_t do_cksum(uint16_t val)
static uint32_t get_frame(uint16_t laserdiff)
{
uint32_t frame = 0;
- uint16_t frame_dist = 256;
- uint16_t step, val;
+ uint16_t val, mid, min, max;
/* for calibration, return the time */
- if (0)
- return laserdiff;
+#ifdef INC_FRAME
+ static uint16_t fr = 1;
+ fr += 2;
+ return fr;
+#endif
+#ifdef SEND_RAWTIME
+ return laserdiff | 1; /* frame must be odd */
+#endif
+
+ min = 0;
+ max = 511;
+ while (min != max) {
+ mid = (max + min + 1) / 2;
+ val = pgm_read_word(&framedist_table[mid]);
- for (step = 128; step != 0; step /= 2) {
- val = pgm_read_word(&framedist_table[frame_dist]);
if (laserdiff > val)
- frame_dist -= step;
+ max = mid - 1;
else
- frame_dist += step;
+ min = mid;
}
- frame |= ((uint32_t)(frame_dist & FRAME_DATA_MASK) << FRAME_DATA_SHIFT);
+ frame |= ((uint32_t)((min << FRAME_DATA_SHIFT)
+ & FRAME_DATA_MASK));
+ frame |= BEACON_ID;
/* process cksum and return */
return do_cksum(frame);
uint16_t time1, time2;
uint16_t diff;
-#if (defined SPEED_40RPS) || (defined SPEED_20RPS)
/* set timer to 16Mhz, we will use ICP */
TCCR1A = 0;
TCCR1B = _BV(CS10);
-#else /* 10 RPS */
- /* set timer to 2Mhz, we will use ICP */
- TCCR1A = 0;
- TCCR1B = _BV(CS11);
-#endif
- /* wait until all is off (inverted logic) */
+ /* wait until all is off (inverted logic) */
while (READ_PHOTO() == 0);
TIFR = _BV(ICF1);
/* process time difference */
diff = time2 - time1;
- if (diff < MIN_INTER_TIME)
+ if (diff > MAX_INTER_TIME)
return -1;
+ /*
+ * diff/2 is < 32768
+ * ir_delay is < 32768
+ * current time is ~time1 + diff
+ */
*when = time1 + (diff/2) + IR_DELAY;
*laserdiff = diff;
/* laser ok */
return 0;
}
-#endif
/* */
{
/* must be odd */
uint32_t frame = FRAME;
-#ifdef WAIT_LASER
int8_t ret;
uint16_t when = 0;
uint16_t diff = 0;
-#endif
+
/* LEDS */
LED_DDR = _BV(LED1_BIT) | _BV(LED2_BIT) | _BV(LED3_BIT);
IR_DDR |= _BV(IR_BIT);
DDRB |= 0x08;
OCR2 = 50;
TCCR2 = _BV(WGM21) | _BV(WGM20) | _BV(COM21) | _BV(CS21) ;
-
+
while (1);
#endif
+#ifdef LOCK_BUS
+ LOCKBUS_PORT &= (~_BV(LOCKBUS_BIT));
+#endif
/* configure timer 0, prescaler = 64 */
TCCR0 = _BV(CS01) | _BV(CS00);
if (ret)
continue;
+#endif /* WAIT_LASER */
+
+#ifdef LOCK_BUS
+ if ((LOCKBUS_PIN & _BV(LOCKBUS_BIT)) == 0)
+ continue;
+ LOCKBUS_DDR |= _BV(LOCKBUS_BIT);
+#endif
+#ifdef FIXED_FRAME
+ frame = FRAME;
+#else
frame = get_frame(diff);
+#endif /* FIXED_FRAME */
/* cannot convert into frame... skip it */
if (frame == 0) {
wait_ms(INTER_LASER_TIME);
continue;
}
+
+#ifdef WAIT_LASER
/* wait before IR xmit */
while ((int16_t)(when-TCNT1) > 0);
-#endif
+#endif /* WAIT_LASER */
LED3_ON();
/* ok, transmit frame */
LED3_OFF();
+#ifdef LOCK_BUS
+ LOCKBUS_DDR &= (~_BV(LOCKBUS_BIT));
+#endif
+
/* don't watch a laser during this time */
wait_ms(INTER_LASER_TIME);
}
git.droids-corp.org / aversive.git / blobdiff