* project payload developed at Challenger Middle School.
*/
-volatile __data uint16_t ao_icp3_count = 0;
-volatile __data uint16_t ao_icp3_last = 0;
-
-uint16_t ao_icp3(void)
-{
- uint16_t v;
- ao_arch_critical(
- v = ao_icp3_count;
- );
- return v;
-}
+volatile __data uint16_t ao_tick3_count;
static void
ao_pwmin_display(void) __reentrant
{
- /* display the most recent value */
- printf("icp 3: %5u\n", ao_icp3());
+ 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);
-ISR(TIMER3_CAPT_vect)
+}
+ISR(TIMER3_COMPA_vect)
{
-
- uint8_t lo = ICR3L;
- uint8_t hi = ICR3H;
- uint16_t ao_icp3_this = (hi <<8) | lo;
-
- /* handling counter rollovers */
- if (ao_icp3_this >= ao_icp3_last)
- ao_icp3_count = ao_icp3_this - ao_icp3_last;
- else
- ao_icp3_count = ao_icp3_this + (65536 - ao_icp3_last);
- ao_icp3_last = ao_icp3_this;
+ ++ao_tick3_count;
}
__code struct ao_cmds ao_pwmin_cmds[] = {
/* do hardware setup here */
TCCR3A = ((0 << WGM31) | /* normal mode, OCR3A */
(0 << WGM30)); /* normal mode, OCR3A */
- TCCR3B = ((1 << ICNC3) | /* input capture noise canceler on */
+ TCCR3B = ((0 << ICNC3) | /* no input capture noise canceler */
(0 << ICES3) | /* input capture on falling edge (don't care) */
(0 << WGM33) | /* normal mode, OCR3A */
(0 << WGM32) | /* normal mode, OCR3A */
- (3 << CS30)); /* clk/64 from prescaler */
+ (4 << CS30)); /* clk/256 from prescaler */
-
+ OCR3A = 1250; /* 8MHz clock */
- TIMSK3 = (1 << ICIE3); /* Interrupt on input compare */
+ TIMSK3 = (1 << OCIE3A); /* Interrupt on compare match */
/* set the spike filter bit in the TCCR3B register */