Big update here.
delayMicrosecondsHard re-written - again.
Added a serialRead example program, and added in the okLed
to the examples too.
Updated/checked some of the GPIO/PWM code.
Added in some experimental servo and tone generating code and
and example or 2.
Tweaks to the gpio command to correctly load the I2C modules too.
diff --git a/examples/delayTest.c b/examples/delayTest.c
index 8c95522..d05f3ff 100644
--- a/examples/delayTest.c
+++ b/examples/delayTest.c
@@ -3,30 +3,24 @@
#include <unistd.h>
#include <wiringPi.h>
-#include <time.h>
-#include <sys/types.h>
#include <sys/time.h>
#define CYCLES 1000
-#define DELAY 99
int main()
{
int x ;
struct timeval t1, t2 ;
- long long t ;
- unsigned int max, min ;
-
- unsigned int values [CYCLES] ;
-
- max = 0 ;
- min = 1000000 ;
+ int t ;
+ int max, min ;
+ int del ;
+ int underRuns, overRuns, exactRuns, total ;
+ int descheds ;
if (wiringPiSetup () == -1)
return 1 ;
- piHiPri (10) ;
- sleep (1) ;
+ piHiPri (10) ; sleep (1) ;
// Baseline test
@@ -34,35 +28,56 @@
gettimeofday (&t2, NULL) ;
t = t2.tv_usec - t1.tv_usec ;
- printf ("Baseline test: %lld\n", t);
+ printf ("Baseline test: %d\n", t);
- for (x = 0 ; x < CYCLES ; ++x)
+ for (del = 1 ; del < 200 ; ++del)
{
- gettimeofday (&t1, NULL) ;
- delayMicroseconds (DELAY) ;
- gettimeofday (&t2, NULL) ;
-
- t = t2.tv_usec - t1.tv_usec ;
- if (t > max) max = t ;
- if (t < min) min = t ;
- values [x] = t ;
- }
+ underRuns = overRuns = exactRuns = total = 0 ;
+ descheds = 0 ;
+ max = del ;
+ min = del ;
- printf ("Done: Max: %d, min: %d\n", max, min) ;
+ for (x = 0 ; x < CYCLES ; ++x)
+ {
+ for (;;) // Repeat this if we get a delay over 999uS
+ { // -> High probability Linux has deschedulled us
+ gettimeofday (&t1, NULL) ;
+ delayMicroseconds (del) ;
+ gettimeofday (&t2, NULL) ;
- for (x = 0 ; x < CYCLES ; ++x)
- {
- printf ("%4d", values [x]) ;
- if (values [x] > DELAY)
- printf (".") ;
- else if (values [x] < DELAY)
- printf ("-") ;
- else
- printf (" ") ;
- if (((x + 1) % 20) == 0)
- printf ("\n") ;
+ if (t2.tv_usec < t1.tv_usec) // Counter wrapped
+ t = (1000000 + t2.tv_usec) - t1.tv_usec;
+ else
+ t = t2.tv_usec - t1.tv_usec ;
+ if (t > 999)
+ {
+ ++descheds ;
+ continue ;
+ }
+ else
+ break ;
+ }
+
+ if (t > max)
+ {
+ max = t ;
+ ++overRuns ;
+ }
+ else if (t < min)
+ {
+ min = t ;
+ ++underRuns ;
+ }
+ else
+ ++exactRuns ;
+
+ total += t ;
+ }
+ printf ("Delay: %3d. Min: %3d, Max: %3d, Unders: %3d, Overs: %3d, Exacts: %3d, Average: %3d, Descheds: %2d\n",
+ del, min, max, underRuns, overRuns, exactRuns, total / CYCLES, descheds) ;
+ fflush (stdout) ;
+ delay (1) ;
}
- printf ("\n") ;
return 0 ;
}