ProtoThreads多線(xiàn)程實(shí)例

ID:112317 · 發(fā)表于 2016-4-9 20:14

發(fā)一個(gè)我前段時(shí)間用ProtoThreads寫(xiě)的一個(gè)讀取Serial角度并用模擬的方式驅(qū)動(dòng)舵機(jī)
關(guān)于ProtoThreads的介紹：http://www.torrancerestoration.com/bbs/dpj-47836-1.html
代碼如下

#include <PT_timer.h>
#include <pt.h>
int servopin=8;//定義舵機(jī)接口數(shù)字接口7
int myangle=100;//定義角度變量
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;//定義脈寬變量
myangle%=156;//視舵機(jī)而定，防止越界
pulsewidth=myangle*11+500;//將角度轉(zhuǎn)化為500-2205的脈寬值
digitalWrite(servopin,HIGH);//將舵機(jī)接口電平至高
delayMicroseconds(pulsewidth);//延時(shí)脈寬值的微秒數(shù)
digitalWrite(servopin,LOW);//將舵機(jī)接口電平至低
}
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);//設(shè)定舵機(jī)接口為輸出接口
PT_INIT(&pt1);
PT_INIT(&pt2);
Serial.begin(9600);
}
void loop()//
{
servoMove(&pt1);
angleRead(&pt2);
}

復(fù)制代碼

ServoMove呢就是自己模擬出來(lái)的舵機(jī)函數(shù)，為什么不用servo庫(kù)呢？因?yàn)閍rduino自身的servo庫(kù)有很多限制，第一PWM不能用了，第二最小角度只有1度，當(dāng)然這個(gè)程序里舵機(jī)的精度也是1度，只要把相應(yīng)的變量改成float就能精確到小數(shù)了，不過(guò)最大的好處是舵機(jī)腳可以任意設(shè)定
servomove中限定了最大角度為155度，這個(gè)與舵機(jī)有關(guān)
angleRead中使用了stringtoInt，每次可以輸入一個(gè)角度，角度可以以空格或回車(chē) 結(jié)尾（操蛋的VC2010 SerialMonitor發(fā)送數(shù)據(jù)不帶回車(chē)的。。那就空格了）
程序中使用了定時(shí)器，自己用C++寫(xiě)的，第一次寫(xiě)庫(kù)，照葫蘆畫(huà)瓢了。。。
感謝czad的擴(kuò)展庫(kù)翻譯:http://www.torrancerestoration.com/bbs/dpj-47837-1.html
這個(gè)庫(kù)用起來(lái)非常簡(jiǎn)單：
PT_Timer t;//定義一個(gè)定時(shí)器
t.setTimer(unsinged long time) //定時(shí)時(shí)間，單位ms
t.Expired()//判斷定時(shí)器是否溢出，是返回值>0
在上面的代碼中，一個(gè)舵機(jī)周期是20ms，前面的約2.5毫秒是信號(hào)周期，剩下的10多ms全是無(wú)用的低電平，然而又必不可少，所以果斷用定時(shí)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__ */
/** @} */

復(fù)制代碼

附上

ProtoThreads Timer.rar (13.23 KB, 下載次數(shù): 11)

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ProtoThreads多線(xiàn)程實(shí)例

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