Dear Sir,
Thanks for all suggestion to all.
I am able to synchronize properly Beaglebone with NMEA serial frame and 1pps
from GPS receiver. Below shown in output.
root@am335x-evm:/bin# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
oGPS_NMEA(0) .GPS. 0 l 1 16 377 0.000 -0.013 0.031
Problem was that there was not timepps.h file present in /usr/include due to
which it was detecting nmea frame only.
But, now i want to read the system time at every 1pps interrupt.
I tried with using function
do_gettimeofday(&m_now);
time_to_tm(m_now.tv_sec,0,&m_systime);
It works but sometime there is repeat in seconds at 1pps. I am not
understanding the issue. i am using signal method to transmit signal from
kernel module to user space program at every 1pps.
Details are given below:
kernel module:
void pps_rcvd_function(void)
{
//printk("PPSTIMER: PPS rcvd\n");
int ret_pps;
int temp_year=0,temp_mon=0;
if (interrupt_signal_flag == 1)
{
ret_pps = send_sig_info(SIG_TEST, &info, current_task); //send the signal
}
static long m_ppstimer_ioctl(struct file *file, unsigned int cmd, unsigned long
arg)
{
switch (cmd)
{
case CLOCK_READ:
do_gettimeofday(&m_now);
time_to_tm(m_now.tv_sec,0,&m_systime);
//time1 = systime;
copy_to_user((struct m_system_time *)arg,&m_systime, sizeof(struct
m_system_time));
break;
default:
printk(KERN_ALERT "ppstimer - wrong command:\n");
break;
}
return 0;
}
User space:
void receiveData(int n, siginfo_t *info, void *unused) {
//printf("PPSTIMER=received value %i\n", info->si_int);
ioctl(fd, CLOCK_READ, &user_time);
pps_flag_signal = 1;
printf("User Space Time: %02d:%02d:%02d %02d/%02d/%02d \n",
user_time.hour,user_time.min,user_time.sec,user_time.mday,(user_time.mon+1),
(1900+user_time.year));
}
receiveData function is my signal handler at user space.
I am concern if it is problem that the system time dosen-t get updated
sometimes at 1pps signal receive at assert level.
I will appreciate if any suggestion.
Thanks & Regards
Ajay
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