- uint8_t photos;
- uint8_t time1, time2;
- uint8_t diff;
-
- /*
- wait photo on
- wait photo off
- wait photo on or timeout
- wait photo off
- should return the amount of time to wait
- */
-
- /* wait until all is off */
- while (READ_PHOTO() != 0);
-
- /* wait until photo is on */
- while (READ_PHOTO() != 1);
- time1 = TCNT0;
+ uint32_t frame = 0;
+ frame |= ((uint32_t)BEACON_ID << BEACON_ID_SHIFT);
+ frame |= ((uint32_t)(laserdiff & FRAME_DATA_MASK) << FRAME_DATA_SHIFT);
+ return frame;
+}
+
+/* Wait 2 consecutive rising edges on photodiode. Return 0 on success,
+ * in this case, the 'when' pointed area is assigned to the time when
+ * IR signal should be sent. The 'laserdiff' pointer is the time
+ * between the 2 lasers, in timer unit. */
+static inline int8_t wait_laser(uint16_t *when, uint16_t *laserdiff)
+{
+ uint16_t time1, time2;
+ uint16_t diff;
+
+#ifdef SPEED_40RPS
+ /* 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) */
+ while (READ_PHOTO() == 0);
+ TIFR = _BV(ICF1);
+
+ /* wait falling edge */
+ while ((TIFR & _BV(ICF1)) == 0);
+ time1 = ICR1;
+