Jetson TK1 integrated RTC WakeUp demo

README.md

download wake_jetson_up_in.c file and compile with following command:

wget https://gist.githubusercontent.com/RafaelKa/b1cbb4990a04134dcc03/raw/wake_jetson_up_in.c
gcc -s -Wall -Wstrict-prototypes wake_jetson_up_in.c -o wake_jetson_up_in

run

sudo ./wake_jetson_up_in 180
sudo shutdown -h now && exit

Jetson TK1 powers up by RTC WakeUp in next 3 minutes

wake_jetson_up_in.c

/*
 *	  Evidence that Jetson TK1 integrated RTC works
 *
 *	  Compile with:
 *			 gcc -s -Wall -Wstrict-prototypes wake_jetson_up_in.c -o wake_jetson_up_in
 *
 *	  @ RafaelKa
 *
 */

#include <stdio.h>
#include <linux/rtc.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>


int main(int argc, char **argv) {
	int fd, retval, minutes = 0, seconds = 120;
	struct rtc_time rtc_tm;
	struct rtc_wkalrm rtc_wake_alarm;
	const char *rtc = "/dev/rtc0";

	switch (argc) {
	case 2:
		seconds = atoi(argv[1]);
	case 1:
		break;
	default:
		fprintf(stderr, "usage:  wake_jetson_up_in seconds\n");
		return 1;
	}

	fd = open(rtc, O_RDONLY);

	if (fd ==  -1) {
		perror(rtc);
		exit(errno);
	}

	fprintf(stderr, "\n\t\tJetson TK1 Wake-Up Demo\n\n");

	/* Read current date-time from RTC device */
	retval = ioctl(fd, RTC_RD_TIME, &rtc_tm);
	if (retval == -1) {
		perror("RTC_RD_TIME ioctl");
		exit(errno);
	}

	fprintf(stderr, "Current time is %02d:%02d:%02d .\n\n", rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);

	rtc_tm.tm_sec += seconds;
	if (rtc_tm.tm_sec >= 60) {
		rtc_tm.tm_sec %= 60;
		minutes = seconds/60;
		rtc_tm.tm_min += minutes;
		rtc_tm.tm_min %= 60;
	}

	retval = ioctl(fd, RTC_WKALM_RD, &rtc_wake_alarm);
	if (retval == -1) {
		perror("RTC_WKALM_RD ioctl");
		exit(errno);
	}

	rtc_wake_alarm.enabled = 1;
	rtc_wake_alarm.time = rtc_tm;
	retval = ioctl(fd, RTC_WKALM_SET, &rtc_wake_alarm);
	if (retval == -1) {
		perror("RTC_WKALM_SET ioctl");
		exit(errno);
	}

	fprintf(stderr, "Jetson TK1 will wake up in %02d minutes %02d seconds, \n\n         Also @ %02d:%02d:%02d .\n\nPlease run: \"sudo shutdown -h now\"\n",
		minutes%60, seconds%60, rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);

	return 0;
}

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