nuttx-apps/examples/rgbled/rgbled.c

119 lines
3.6 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
****************************************************************************/
#ifdef CONFIG_BUILD_KERNEL
int main(int argc, FAR char *argv[])
#else
int rgbled_main(int argc, char *argv[])
#endif
{
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);
(void)write(fd, buffer, 8);
usleep(5000);
}
return 0;
}