nuttx-apps/examples/rgbled/rgbled.c
Xiang Xiao 857158451b Unify the void cast usage
1.Remove void cast for function because many place ignore the returned value witout cast
2.Replace void cast for variable with UNUSED macro

Change-Id: Ie644129a563244a6397036789c4c3ea83c4e9b09
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2020-01-02 23:21:01 +08:00

115 lines
3.5 KiB
C

/****************************************************************************
* examples/rgbled/rgbled.c
*
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
* Author: Alan Carvalho de Assis <acassis@gmail.com>
*
* 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 <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_EXAMPLES_RGBLED_DEVNAME
# define CONFIG_EXAMPLES_RGBLED_DEVNAME "/dev/rgbled0"
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* rgbled_main
****************************************************************************/
int main(int argc, FAR char *argv[])
{
int red = 255;
int green = 0;
int blue = 0;
int sred = -1;
int sgreen = 1;
int sblue = 0;
int fd;
char buffer[8];
fd = open(CONFIG_EXAMPLES_RGBLED_DEVNAME, O_WRONLY);
if (fd < 0)
{
printf("Error opening %s!\n", CONFIG_EXAMPLES_RGBLED_DEVNAME);
return -1;
}
while(1)
{
red += sred;
green += sgreen;
blue += sblue;
if (green == 255)
{
sred = 0;
sgreen = -1;
sblue = 1;
}
if (blue == 255)
{
sred = 1;
sgreen = 0;
sblue = -1;
}
if (red == 255)
{
sred = -1;
sblue = 0;
sgreen = 1;
}
sprintf(buffer, "#%02X%02X%02X", red, green, blue);
write(fd, buffer, 8);
usleep(5000);
}
return 0;
}