* project payload developed at Challenger Middle School.
*/
-volatile __data uint16_t ao_tick3_count;
+volatile __data uint16_t ao_icp3_count;
static void
ao_pwmin_display(void) __reentrant
{
- uint8_t lo = TCNT1L;
- uint8_t hi = TCNT1H;
- uint16_t value = (hi <<8) | lo;
-
- uint8_t lo3 = TCNT3L;
- uint8_t hi3 = TCNT3H;
- uint16_t value3 = (hi3 <<8) | lo3;
-
- /* now display the value we read */
- printf("timer 1: %5u %2x %2x\n", value, hi, lo);
- printf("timer 3: %5u %2x %2x\n", value3, hi3, lo3);
+ /* display the most recent value */
+ printf("icp 3: %5u\n", ao_icp3_count);
}
-ISR(TIMER3_COMPA_vect)
+ISR(TIMER3_CAPT_vect)
{
- ++ao_tick3_count;
+ uint8_t lo = ICR3L;
+ uint8_t hi = ICR3H;
+ ao_icp3_count = (hi <<8) | lo;
}
__code struct ao_cmds ao_pwmin_cmds[] = {
/* do hardware setup here */
TCCR3A = ((0 << WGM31) | /* normal mode, OCR3A */
(0 << WGM30)); /* normal mode, OCR3A */
- TCCR3B = ((0 << ICNC3) | /* no input capture noise canceler */
+ TCCR3B = ((1 << ICNC3) | /* input capture noise canceler on */
(0 << ICES3) | /* input capture on falling edge (don't care) */
(0 << WGM33) | /* normal mode, OCR3A */
(0 << WGM32) | /* normal mode, OCR3A */
(4 << CS30)); /* clk/256 from prescaler */
- OCR3A = 1250; /* 8MHz clock */
+
- TIMSK3 = (1 << OCIE3A); /* Interrupt on compare match */
+ TIMSK3 = (1 << ICIE3); /* Interrupt on input compare */
/* set the spike filter bit in the TCCR3B register */