136 lines
3.9 KiB
C
136 lines
3.9 KiB
C
/****************************************************************************
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* apps/examples/zerocross/zerocross_main.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/ioctl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <debug.h>
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#include <nuttx/sensors/zerocross.h>
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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/* Configuration ************************************************************/
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#ifndef CONFIG_SENSORS_ZEROCROSS
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# error "CONFIG_SENSORS_ZEROCROSS is not defined in the configuration"
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#endif
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#ifndef CONFIG_EXAMPLES_ZEROCROSS_DEVNAME
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# define CONFIG_EXAMPLES_ZEROCROSS_DEVNAME "/dev/zc0"
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#endif
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#ifndef CONFIG_EXAMPLES_ZEROCROSS_SIGNO
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# define CONFIG_EXAMPLES_ZEROCROSS_SIGNO 13
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#endif
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/* Helpers ******************************************************************/
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#ifndef MIN
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# define MIN(a,b) (a < b ? a : b)
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#endif
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#ifndef MAX
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# define MAX(a,b) (a > b ? a : b)
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#endif
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* zerocross_main
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****************************************************************************/
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int main(int argc, FAR char *argv[])
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{
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struct sigevent event;
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int fd;
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int tmp;
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int ret;
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int errcode = EXIT_FAILURE;
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/* Open the zerocross device */
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fd = open(CONFIG_EXAMPLES_ZEROCROSS_DEVNAME, O_RDONLY);
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if (fd < 0)
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{
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fprintf(stderr, "ERROR: Failed to open %s: %d\n",
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CONFIG_EXAMPLES_ZEROCROSS_DEVNAME, errno);
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return EXIT_FAILURE;
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}
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/* Register to receive a signal on every zero cross event */
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event.sigev_notify = SIGEV_SIGNAL;
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event.sigev_signo = CONFIG_EXAMPLES_ZEROCROSS_SIGNO;
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ret = ioctl(fd, ZCIOC_REGISTER, (unsigned long)((uintptr_t)&event));
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if (ret < 0)
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{
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fprintf(stderr, "ERROR: ioctl(ZCIOC_REGISTER) failed: %d\n", errno);
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goto errout_with_fd;
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}
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/* Ignore the default signal action */
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signal(CONFIG_EXAMPLES_ZEROCROSS_SIGNO, SIG_IGN);
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/* Then loop, receiving signals indicating zero cross events. */
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for (; ; )
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{
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struct siginfo value;
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sigset_t set;
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ssize_t nread;
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/* Wait for a signal */
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sigemptyset(&set);
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sigaddset(&set, CONFIG_EXAMPLES_ZEROCROSS_SIGNO);
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ret = sigwaitinfo(&set, &value);
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if (ret < 0)
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{
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fprintf(stderr, "ERROR: sigwaitinfo() failed: %d\n", errno);
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goto errout_with_fd;
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}
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/* Show the value accompanying the signal */
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printf("Signal received!\n");
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printf("Sample = %d\n", value.si_value.sival_int);
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}
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errcode = EXIT_SUCCESS;
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errout_with_fd:
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close(fd);
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return errcode;
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}
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