nuttx-apps/examples/zerocross/zerocross_main.c

149 lines
4.7 KiB
C

/****************************************************************************
* examplex/zerocross/zerocross_main.c
*
* Copyright (C) 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/sensors/zerocross.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifndef CONFIG_SENSORS_ZEROCROSS
# error "CONFIG_SENSORS_ZEROCROSS is not defined in the configuration"
#endif
#ifndef CONFIG_EXAMPLES_ZEROCROSS_DEVNAME
# define CONFIG_EXAMPLES_ZEROCROSS_DEVNAME "/dev/zc0"
#endif
#ifndef CONFIG_EXAMPLES_ZEROCROSS_SIGNO
# define CONFIG_EXAMPLES_ZEROCROSS_SIGNO 13
#endif
/* Helpers ******************************************************************/
#ifndef MIN
# define MIN(a,b) (a < b ? a : b)
#endif
#ifndef MAX
# define MAX(a,b) (a > b ? a : b)
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* zerocross_main
****************************************************************************/
#ifdef CONFIG_BUILD_KERNEL
int main(int argc, FAR char *argv[])
#else
int zerocross_main(int argc, char *argv[])
#endif
{
struct zc_notify_s notify;
int fd;
int tmp;
int ret;
int errcode = EXIT_FAILURE;
/* Open the zerocross device */
fd = open(CONFIG_EXAMPLES_ZEROCROSS_DEVNAME, O_RDONLY);
if (fd < 0)
{
fprintf(stderr, "ERROR: Failed to open %s: %d\n",
CONFIG_EXAMPLES_ZEROCROSS_DEVNAME, errno);
return EXIT_FAILURE;
}
/* Register to receive a signal on every zero cross event */
notify.zc_signo = CONFIG_EXAMPLES_ZEROCROSS_SIGNO;
ret = ioctl(fd, ZCIOC_REGISTER, (unsigned long)((uintptr_t)&notify));
if (ret < 0)
{
fprintf(stderr, "ERROR: ioctl(ZCIOC_REGISTER) failed: %d\n", errno);
goto errout_with_fd;
}
/* Then loop, receiving signals indicating zero cross events. */
for (; ; )
{
struct siginfo value;
sigset_t set;
ssize_t nread;
/* Wait for a signal */
(void)sigemptyset(&set);
(void)sigaddset(&set, CONFIG_EXAMPLES_ZEROCROSS_SIGNO);
ret = sigwaitinfo(&set, &value);
if (ret < 0)
{
fprintf(stderr, "ERROR: sigwaitinfo() failed: %d\n", errno);
goto errout_with_fd;
}
/* Show the value accompanying the signal */
printf("Signal received!\n");
printf("Sample = %d\n", value.si_value.sival_int);
}
errcode = EXIT_SUCCESS;
errout_with_fd:
close(fd);
return errcode;
}