Revert "telescience: correctly calculating rate values with higher resolution"

[fw/altos] / src / avr / ao_pwmin.c

diff --git a/src/avr/ao_pwmin.c b/src/avr/ao_pwmin.c
index 84397357a7ee89ee4967b3300f0e2b49950cb62f..73a153b2e4cc67332b879e18b02febe1333687c5 100644 (file)
--- a/src/avr/ao_pwmin.c
+++ b/src/avr/ao_pwmin.c
@@ -25,40 +25,20 @@
  * 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_icp3_count;
 
 static void
 ao_pwmin_display(void) __reentrant
 {
        /* display the most recent value */
-       printf("icp 3: %5u\n", ao_icp3());
+       printf("icp 3: %5u\n", ao_icp3_count);
 
 }
-
-
 ISR(TIMER3_CAPT_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_icp3_count = (hi <<8) | lo;
 }
 
 __code struct ao_cmds ao_pwmin_cmds[] = {
@@ -76,7 +56,7 @@ ao_pwmin_init(void)
                   (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 */