Contiki 2.6

pwm.h

00001 /*
00002  * Copyright (c) 2010, Mariano Alvira <mar@devl.org> and other contributors
00003  * to the MC1322x project (http://mc1322x.devl.org)
00004  * All rights reserved.
00005  *
00006  * Redistribution and use in source and binary forms, with or without
00007  * modification, are permitted provided that the following conditions
00008  * are met:
00009  * 1. Redistributions of source code must retain the above copyright
00010  *    notice, this list of conditions and the following disclaimer.
00011  * 2. Redistributions in binary form must reproduce the above copyright
00012  *    notice, this list of conditions and the following disclaimer in the
00013  *    documentation and/or other materials provided with the distribution.
00014  * 3. Neither the name of the Institute nor the names of its contributors
00015  *    may be used to endorse or promote products derived from this software
00016  *    without specific prior written permission.
00017  *
00018  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
00019  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00020  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00021  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
00022  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00023  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00024  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00025  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00026  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00027  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00028  * SUCH DAMAGE.
00029  *
00030  * This file is part of libmc1322x: see http://mc1322x.devl.org
00031  * for details.
00032  *
00033  *
00034  */
00035 
00036 #ifndef PWM_H
00037 #define PWM_H
00038 
00039 /* Initialize PWM output.
00040    timer_num = 0, 1, 2, 3
00041    rate = desired rate in Hz,
00042    duty = desired duty cycle.  0=always off, 65536=always on.
00043    enable_timer = whether to actually run the timer, versus just configuring it
00044    Returns actual PWM rate. */
00045 uint32_t pwm_init_ex(int timer_num, uint32_t rate, uint32_t duty, int enable_timer);
00046 
00047 /* Initialize PWM output, helper macros
00048    timer = TMR0, TMR1, TMR2, TMR2
00049    rate = desired rate in Hz,
00050    duty = desired duty cycle.  0=always off, 65536=always on.
00051    Returns actual PWM rate. */
00052 #define pwm_init(timer,rate,duty) pwm_init_ex(TMR_NUM(timer), rate, duty, 1)
00053 #define pwm_init_stopped(timer,rate,duty) pwm_init_ex(TMR_NUM(timer), rate, duty, 0)
00054 
00055 /* Change duty cycle.  Safe to call at any time.
00056    timer_num = 0, 1, 2, 3
00057    duty = desired duty cycle.  0=always off, 65536=always on.
00058 */
00059 void pwm_duty_ex(int timer_num, uint32_t duty);
00060 
00061 /* Change duty cycle.  Safe to call at any time.
00062    timer = TMR0, TMR1, TMR2, TMR2
00063    duty = desired duty cycle.  0=always off, 65536=always on.
00064 */
00065 #define pwm_duty(timer,duty) pwm_duty_ex(TMR_NUM(timer), duty)
00066 
00067 #endif