wiringPi_Blueberry/examples/okLed.c
2023-08-11 15:53:17 +08:00

83 lines
2.1 KiB
C

/*
* okLed.c:
* Make the OK LED on the Pi Pulsate...
*
* Originally posted to the Raspberry Pi forums:
* http://www.raspberrypi.org/phpBB3/viewtopic.php?p=162581#p162581
*
* Compile this and store it somewhere, then kick it off at boot time
* e.g. by putting it in /etc/rc.local and running it in the
* background &
*
* Copyright (c) 2012-2013 Gordon Henderson. <projects@drogon.net>
***********************************************************************
* This file is part of wiringPi:
* https://projects.drogon.net/raspberry-pi/wiringpi/
*
* wiringPi is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* wiringPi is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with wiringPi. If not, see <http://www.gnu.org/licenses/>.
***********************************************************************
*/
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <math.h>
#include <wiringPi.h>
#include <softPwm.h>
// The OK/Act LED is connected to BCM_GPIO pin 16
#define OK_LED 16
int main ()
{
int fd, i ;
wiringPiSetupGpio () ;
// Change the trigger on the OK/Act LED to "none"
if ((fd = open ("/sys/class/leds/led0/trigger", O_RDWR)) < 0)
{
fprintf (stderr, "Unable to change LED trigger: %s\n", strerror (errno)) ;
return 1 ;
}
write (fd, "none\n", 5) ;
close (fd) ;
softPwmCreate (OK_LED, 0, 100) ;
for (;;)
{
for (i = 0 ; i <= 100 ; ++i)
{
softPwmWrite (OK_LED, i) ;
delay (10) ;
}
delay (50) ;
for (i = 100 ; i >= 0 ; --i)
{
softPwmWrite (OK_LED, i) ;
delay (10) ;
}
delay (10) ;
}
return 0 ;
}