发一个我前段时间用ProtoThreads写的一个读取Serial角度并用模拟的方式驱动舵机
关于ProtoThreads的介绍:http://www.51hei.com/bbs/dpj-47836-1.html
代码如下
- #include <PT_timer.h>
- #include <pt.h>
- int servopin=8;//定义舵机接口数字接口7
- int myangle=100;//定义角度变量
- int val=0;
- static struct pt pt1,pt2;
- PT_timer servotimer;
- static int servoMove(struct pt *pt)
- {
- PT_BEGIN(pt);
- while(1)
- {
- servotimer.setTimer(25);
- PT_WAIT_UNTIL(pt,servotimer.Expired());
- int pulsewidth;//定义脉宽变量
- myangle%=156;//视舵机而定,防止越界
- pulsewidth=myangle*11+500;//将角度转化为500-2205的脉宽值
- digitalWrite(servopin,HIGH);//将舵机接口电平至高
- delayMicroseconds(pulsewidth);//延时脉宽值的微秒数
- digitalWrite(servopin,LOW);//将舵机接口电平至低
- }
- PT_END(pt);
- }
- String inString = "";
- static int angleRead(struct pt *pt)
- {
- PT_BEGIN(pt);
- while(1) {
- PT_WAIT_UNTIL(pt, Serial.available()>0);
- int inChar = Serial.read();
- if (isDigit(inChar))
- inString += (char)inChar;
- if (inChar == ' '||inChar=='\n') {
- myangle=inString.toInt();
- Serial.print("myangle=");
- Serial.println(myangle);
- inString = "";
- }
- }
- PT_END(pt);
- }
- void setup()
- {
- pinMode(servopin,OUTPUT);//设定舵机接口为输出接口
- PT_INIT(&pt1);
- PT_INIT(&pt2);
- Serial.begin(9600);
- }
- void loop()//
- {
- servoMove(&pt1);
- angleRead(&pt2);
- }
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ServoMove呢就是自己模拟出来的舵机函数,为什么不用servo库呢?因为arduino自身的servo库有很多限制,第一PWM不能用了,第二最小角度只有1度,当然这个程序里舵机的精度也是1度,只要把相应的变量改成float就能精确到小数了,不过最大的好处是舵机脚可以任意设定
servomove中限定了最大角度为155度,这个与舵机有关
angleRead中使用了stringtoInt,每次可以输入一个角度,角度可以以 空格 或 回车 结尾(操蛋的VC2010 SerialMonitor发送数据不带 回车的。。那就空格了)
程序中使用了定时器,自己用C++写的,第一次写库,照葫芦画瓢了。。。
感谢czad的扩展库翻译:http://www.51hei.com/bbs/dpj-47837-1.html
这个库用起来非常简单:
PT_Timer t;//定义一个定时器
t.setTimer(unsinged long time) //定时时间,单位ms
t.Expired()//判断定时器是否溢出,是返回值>0
在上面的代码中,一个舵机周期是20ms,前面的约2.5毫秒是信号周期,剩下的10多ms全是无用的低电平,然而又必不可少,所以果断用定时器取代delay
ok
pt.h
- /*
- * Copyright (c) 2004-2006, Swedish Institute of Computer Science.
- * All rights reserved.
- *
- * 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 of the Institute 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 INSTITUTE 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 INSTITUTE 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.
- *
- * Author: Adam Dunkels <adam@sics.se>
- *
- * $Id: pt.h,v 1.6 2006/06/03 11:29:43 adam Exp $
- */
- /**
- * \addtogroup pt
- * @{
- */
- /**
- * \file
- * Protothreads implementation.
- * \author
- * Adam Dunkels <adam@sics.se>
- *
- */
- #ifndef __PT_H__
- #define __PT_H__
- #include "lc.inc"
- struct pt {
- lc_t lc;
- };
- #define PT_WAITING 0
- #define PT_EXITED 1
- #define PT_ENDED 2
- #define PT_YIELDED 3
- /**
- * \name Initialization
- * @{
- */
- /**
- * Initialize a protothread.
- *
- * Initializes a protothread. Initialization must be done prior to
- * starting to execute the protothread.
- *
- * \param pt A pointer to the protothread control structure.
- *
- * \sa PT_SPAWN()
- *
- * \hideinitializer
- */
- #define PT_INIT(pt) LC_INIT((pt)->lc)
- /** @} */
- /**
- * \name Declaration and definition
- * @{
- */
- /**
- * Declaration of a protothread function.
- *
- * This macro is used to declare a protothread function. Protothreads
- * function should be declared with this macro, but can also be
- * declared as regular C functions that return an integer value.
- *
- * \param name_args The name and arguments of the C function
- * implementing the protothread.
- *
- * \hideinitializer
- */
- #define PT_THREAD(name_args) char name_args
- /**
- * Declare the start of a protothread inside the C function
- * implementing the protothread.
- *
- * This macro is used to declare the starting point of a
- * protothread. It should be placed at the start of the function in
- * which the protothread runs. All C statements above the PT_BEGIN()
- * invokation will be executed each time the protothread is scheduled.
- *
- * \param pt A pointer to the protothread control structure.
- *
- * \hideinitializer
- */
- #define PT_BEGIN(pt) { char PT_YIELD_FLAG = 1; LC_RESUME((pt)->lc)
- /**
- * Declare the end of a protothread.
- *
- * This macro is used for declaring that a protothread ends. It must
- * always be used together with a matching PT_BEGIN() macro.
- *
- * \param pt A pointer to the protothread control structure.
- *
- * \hideinitializer
- */
- #define PT_END(pt) LC_END((pt)->lc); PT_YIELD_FLAG = 0; \
- PT_INIT(pt); return PT_ENDED; }
- /** @} */
- /**
- * \name Blocked wait
- * @{
- */
- /**
- * Block and wait until condition is true.
- *
- * This macro blocks the protothread until the specified condition is
- * true.
- *
- * \param pt A pointer to the protothread control structure.
- * \param condition The condition.
- *
- * \hideinitializer
- */
- #define PT_WAIT_UNTIL(pt, condition) \
- do { \
- LC_SET((pt)->lc); \
- if(!(condition)) { \
- return PT_WAITING; \
- } \
- } while(0)
- /**
- * Block and wait while condition is true.
- *
- * This function blocks and waits while condition is true. See
- * PT_WAIT_UNTIL().
- *
- * \param pt A pointer to the protothread control structure.
- * \param cond The condition.
- *
- * \hideinitializer
- */
- #define PT_WAIT_WHILE(pt, cond) PT_WAIT_UNTIL((pt), !(cond))
- /** @} */
- /**
- * \name Hierarchical protothreads
- * @{
- */
- /**
- * Block and wait until a child protothread completes.
- *
- * This macro schedules a child protothread. The current protothread
- * will block until the child protothread completes.
- *
- * \note The child protothread must be manually initialized with the
- * PT_INIT() function before this function is used.
- *
- * \param pt A pointer to the protothread control structure.
- * \param thread The child protothread with arguments
- *
- * \sa PT_SPAWN()
- *
- * \hideinitializer
- */
- #define PT_WAIT_THREAD(pt, thread) PT_WAIT_WHILE((pt), PT_SCHEDULE(thread))
- /**
- * Spawn a child protothread and wait until it exits.
- *
- * This macro spawns a child protothread and waits until it exits. The
- * macro can only be used within a protothread.
- *
- * \param pt A pointer to the protothread control structure.
- * \param child A pointer to the child protothread's control structure.
- * \param thread The child protothread with arguments
- *
- * \hideinitializer
- */
- #define PT_SPAWN(pt, child, thread) \
- do { \
- PT_INIT((child)); \
- PT_WAIT_THREAD((pt), (thread)); \
- } while(0)
- /** @} */
- /**
- * \name Exiting and restarting
- * @{
- */
- /**
- * Restart the protothread.
- *
- * This macro will block and cause the running protothread to restart
- * its execution at the place of the PT_BEGIN() call.
- *
- * \param pt A pointer to the protothread control structure.
- *
- * \hideinitializer
- */
- #define PT_RESTART(pt) \
- do { \
- PT_INIT(pt); \
- return PT_WAITING; \
- } while(0)
- /**
- * Exit the protothread.
- *
- * This macro causes the protothread to exit. If the protothread was
- * spawned by another protothread, the parent protothread will become
- * unblocked and can continue to run.
- *
- * \param pt A pointer to the protothread control structure.
- *
- * \hideinitializer
- */
- #define PT_EXIT(pt) \
- do { \
- PT_INIT(pt); \
- return PT_EXITED; \
- } while(0)
- /** @} */
- /**
- * \name Calling a protothread
- * @{
- */
- /**
- * Schedule a protothread.
- *
- * This function shedules a protothread. The return value of the
- * function is non-zero if the protothread is running or zero if the
- * protothread has exited.
- *
- * \param f The call to the C function implementing the protothread to
- * be scheduled
- *
- * \hideinitializer
- */
- #define PT_SCHEDULE(f) ((f) == PT_WAITING)
- /** @} */
- /**
- * \name Yielding from a protothread
- * @{
- */
- /**
- * Yield from the current protothread.
- *
- * This function will yield the protothread, thereby allowing other
- * processing to take place in the system.
- *
- * \param pt A pointer to the protothread control structure.
- *
- * \hideinitializer
- */
- #define PT_YIELD(pt) \
- do { \
- PT_YIELD_FLAG = 0; \
- LC_SET((pt)->lc); \
- if(PT_YIELD_FLAG == 0) { \
- return PT_YIELDED; \
- } \
- } while(0)
- /**
- * \brief Yield from the protothread until a condition occurs.
- * \param pt A pointer to the protothread control structure.
- * \param cond The condition.
- *
- * This function will yield the protothread, until the
- * specified condition evaluates to true.
- *
- *
- * \hideinitializer
- */
- #define PT_YIELD_UNTIL(pt, cond) \
- do { \
- PT_YIELD_FLAG = 0; \
- LC_SET((pt)->lc); \
- if((PT_YIELD_FLAG == 0) || !(cond)) { \
- return PT_YIELDED; \
- } \
- } while(0)
- /** @} */
- #endif /* __PT_H__ */
- /** @} */
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附上
ProtoThreads Timer.rar
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