Hi
I am using a 800 MHz PIII SBC with QNXNeutrino6.3.2. I need 250 microseconds thread for which I am unable to program the
clock with microseconds resolution
Though I programmed 10 microseconds, but the resolution is around 9.219 microseconds and the calculations go haywire
with this amount of drift.
I have given the code below. Kindly help me.
Shyamala
/* Thread1 is expected to run every 250us ,thread2 every 500us and thread3 every 1sec and all the 3 threads should
perennially run.*/
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/neutrino.h>
#include <pthread.h>
#include <sched.h>
#include <sys/time.h>
#include <sys/siginfo.h>
#include <sys/wait.h>
// diamond driver includes
#include "dscud.h"
float cosval[80],sinval[80];
DSCADSCAN adscan;
DSCB dscb; int i=0;
int j=0;
int j1=0;
int j2=0;
float vol;
void sampling(void);
void measurand(void);
extern float Vr1;
pthread_mutex_t mutex;
void *T1(void *ignored) { struct timespec ts;
struct itimerspec tsr;
struct sched_param p;
clock_gettime(CLOCK_REALTIME,&ts);
p.sched_priority=20;
pthread_setschedparam(pthread_self(),SCHED_FIFO,&p);
while(1)
{
pthread_mutex_lock(&mutex);
sampling();
pthread_mutex_unlock(&mutex);
ts.tv_nsec =250000;
ts.tv_sec =0;
clock_nanosleep(CLOCK_REALTIME,NULL,&ts,NULL);
if (j==0) {dscDIOOutputBit(dscb,1,0,1);j=1;}
else {dscDIOOutputBit(dscb,1,0,0);j=0;}
}
return (void *)0;
}
void *T2(void *ignored) // 1 msec Thread for calculatig the measurands and Protection functions
{ struct timespec ts1;
clock_gettime(CLOCK_REALTIME,&ts1);
while(1)
{ measurand();
delay(1);
if (j1==0) {dscDIOOutputBit(dscb,1,1,1);j1=1;}
else {dscDIOOutputBit(dscb,1,1,0);
j1=0;}
}
return (void *)0;
}
void *T3(void *ignored) { //FILE *fp1;
while(1)
{ sleep(5);
printf("%f \n",Vr1);
if (j2==0) {
dscDIOOutputBit(dscb,1,2,1);j2=1;}
else {dscDIOOutputBit(dscb,1,2,0);j2=0;}
}
return (void *)0;
}
int main(void)
{
pthread_t thread1, thread2,thread3;
void *thread_rc;
pthread_attr_t attr1,attr2,attr3;
struct _clockperiod hercules;
DSCCB dsccb;
DSCADSETTINGS adsettings;
BYTE confbyte;
dscInit(DSC_VERSION);
memset(&dsccb, 0, sizeof(DSCCB));
dsccb.base_address = 0x240;
dsccb.int_level = 5;
dscInitBoard(DSC_HERCEBX, &dsccb, &dscb);
confbyte=0x1e;
dscDIOSetConfig(dscb,&confbyte);
for (i=0;i<80;i++) {
cosval[i]=0.025*cos(i*0.078571429);sinval[i]=0.025*sin(i*0.078571429);
}
memset(&adsettings, 0, sizeof(DSCADSETTINGS));
adsettings.range = RANGE_10;
adsettings.polarity = BIPOLAR;
adsettings.gain = GAIN_1;
adsettings.load_cal = TRUE;
adsettings.scan_interval = SCAN_INTERVAL_9;
dscADSetSettings(dscb, &adsettings);
memset(&adscan, 0, sizeof(DSCADSCAN));
adscan.low_channel = 0;
adscan.high_channel = 0;
hercules.nsec=10000;
hercules.fract = 0;
ClockPeriod(CLOCK_REALTIME,&hercules,NULL,0);
pthread_attr_init(&attr1);
pthread_attr_setdetachstate(&attr1,PTHREAD_CREATE_DETACHED);
pthread_attr_setinheritsched(&attr1,PTHREAD_EXPLICIT_SCHED);
pthread_attr_setschedpolicy(&attr1,SCHED_FIFO);
attr1.param.sched_priority=10;
pthread_attr_init(&attr2);
pthread_attr_setdetachstate(&attr2,PTHREAD_CREATE_DETACHED);
pthread_attr_setinheritsched(&attr2,PTHREAD_EXPLICIT_SCHED);
pthread_attr_setschedpolicy(&attr2,SCHED_RR);
attr2.param.sched_priority=10;
pthread_attr_init(&attr3);
pthread_attr_setdetachstate(&attr3,PTHREAD_CREATE_DETACHED);
pthread_attr_setinheritsched(&attr3,PTHREAD_EXPLICIT_SCHED);
...
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