請問這個(gè)庫函數(shù)程序是怎么循環(huán)執(zhí)行的？

ID:158981 · 發(fā)表于 2018-3-30 09:38

在學(xué)習(xí)使用“大連好人”的EasyStepper的步進(jìn)電機(jī)控制庫函數(shù)。

在看EasyStepper.cpp文件，看到圖片中這個(gè)內(nèi)容非常困惑。明明是if的命令，為什么程序能不斷的循環(huán)？

請大家指教。附件是完整的EasyStepper庫文件。

ID:158981 · 發(fā)表于 2018-3-30 09:39

本帖最后由 duanyz 于 2018-3-30 12:47 編輯

ID:155507 · 發(fā)表于 2018-3-30 11:08

這段是參照網(wǎng)上編碼器讀取程序?qū)懙淖x取步進(jìn)電機(jī)控制脈沖的程序

#define countA 2 //脈沖
#define countB 3 //方向
long int count = 0;
//long int zuobiao = 0;
void setup() {
pinMode(countA, INPUT);
digitalWrite(countA, HIGH); // turn on pullup resistor
pinMode(countB, INPUT);
digitalWrite(countB, HIGH); // turn on pullup resistor
attachInterrupt(0, doCount, LOW ); // encoder pin on interrupt 0 - pin 2
Serial.begin (115200);
Serial.println("start"); // a personal quirk
}
void loop(){
// do some stuff here - the joy of interrupts is that they take care of themselves
}
void doCount() {
/* If pinA and pinB are both high or both low, it is spinning
* forward. If they're different, it's going backward.
*
* For more information on speeding up this process, see
* [Reference/PortManipulation], specifically the PIND register.
*/
if (digitalRead(countA) == digitalRead(countB)) {
count++;
} else {
count--;
}
// noInterrupts();
Serial.println (count, DEC);
// interrupts();
}

復(fù)制代碼

EasyStepper.h

#ifndef EasyStepper_h
#define EasyStepper_h
#include <stdlib.h>
#if ARDUINO >= 100
#include <Arduino.h>
#else
#include <WProgram.h>
#include <wiring.h>
#endif
/**
* author [email]shangcm@gmail.com[/email]
*/
class EasyStepper
{
public:
/**
* to create the EasyStepper
* parameters:
* stepPin the step pin
* directionPin the direction pin
* enablePin the enable pin
* directionPinsInverted if the value is true then invert HIGH/LOW value for direction pin
* enablePinsInverted if the value is true then invert HIGH/LOW value for enable pin
*/
EasyStepper(byte stepPin, byte directionPin, byte enablePin, bool directionPinsInverted, bool enablePinsInverted);
/**
* to startup the EasyStepper
*/
void startup();
/**
* to shutdown the EasyStepper, will release the enable pin to save power
*/
void shutdown();
/**
* to rotate steps from current position with speed, the acceleration = 0
* speed the speed for rotation, the unit is steps per second
* steps the steps to go
*/
void rotate(float speed, int steps);
/**
* to rotate steps from current position with speed
* speed the speed for rotation, the unit is steps per second
* steps the steps to go
* acceleration the acceleration, if it = 0, means no acceleration
*/
void rotate(float speed, int steps, int acceleration);
/**
* to stop the stepper, the motor will stay at current position
*/
void stop();
/**
* run, you must call this as frequently as possible, but at least once per minimum step interval,
* preferably in your main loop.
*/
void run();
/**
* if return true means the action is done
*/
boolean isDone();
/**
* enable the debug mode?
*/
void debugMode(boolean enabled);
protected:
//
private:
boolean debugModeFlag;
byte stepPin;
byte directionPin;
byte enablePin;
bool directionPinsInverted;
bool enablePinsInverted;
int acceleration;
int stage1; // the end step of the stage1
int stage2; // the end step of the stage2
int stepsToGo;
int stepsGone;
float stepTime;
float startTime;
float stage1StepTime;
float stage3StepTime;
unsigned long nextTimestamp;
boolean done;
void step();
};
#endif

復(fù)制代碼

再來看 EasyStepper.cpp （代碼里面有注釋）

#include "EasyStepper.h"
EasyStepper::EasyStepper(byte stepPin, byte directionPin, byte enablePin, bool directionPinsInverted, bool enablePinsInverted)
{
// save the parameters
this->stepPin = stepPin;
this->directionPin = directionPin;
this->enablePin = enablePin;
this->directionPinsInverted = directionPinsInverted;
this->enablePinsInverted = enablePinsInverted;
}
void EasyStepper::startup()
{
// set the pin mode
pinMode(this->stepPin, OUTPUT);
pinMode(this->directionPin, OUTPUT);
pinMode(this->enablePin, OUTPUT);
// enable the stepper
digitalWrite(enablePin, HIGH ^ this->enablePinsInverted);
// initialize the done to true
this->done = true;
}
void EasyStepper::shutdown()
{
// disable the stepper
digitalWrite(enablePin, LOW ^ this->enablePinsInverted);
}
void EasyStepper::debugMode(boolean enabled)
{
this->debugModeFlag = enabled;
}
void EasyStepper::rotate(float speed, int steps)
{
this->rotate(speed, steps, 0);
}
void EasyStepper::rotate(float speed, int steps, int acceleration)
{
// ignore the zero value
if (speed != 0 && steps != 0)
{
if (steps > 0)
{
// CW
digitalWrite(directionPin, HIGH ^ this->directionPinsInverted);
}
else if (steps < 0)
{
// CCW
digitalWrite(directionPin, LOW ^ this->directionPinsInverted);
}
// done flag
this->done = false;
// the steps to go
this->stepsToGo = abs(steps);
// the acceleration
this->acceleration = abs(acceleration);
if (this->stepsToGo <= 4)
{
this->acceleration = 0;
}
// change the speed to stepTime, micro seconds per step
this->stepTime = 1000.0 * 1000.0 / abs(speed);
// start time
this->startTime = this->stepTime * (this->acceleration + 1);
// stage1
this->stage1 = this->stepsToGo / 4;
this->stage1StepTime = (float) this->acceleration * this->stepTime / this->stage1;
// stage2
this->stage2 = this->stepsToGo / 4 * 3;
this->stage3StepTime = (float) this->acceleration * this->stepTime / (this->stepsToGo - this->stage2);
// the steps gone
this->stepsGone = 0;
// current timestamp
unsigned long time = micros();
if (this->debugModeFlag)
{
Serial.print("rotate: direction=");
Serial.print(steps > 0 ? "CW" : "CCW");
Serial.print(", stepsToGo=");
Serial.print(this->stepsToGo);
Serial.print(", acceleration=");
Serial.print(this->acceleration);
Serial.print(", startTime=");
Serial.print(this->startTime);
Serial.print(", stage1=");
Serial.print(this->stage1);
Serial.print(", stage1StepTime=");
Serial.print(this->stage1StepTime);
Serial.print(", stage2=");
Serial.print(this->stage2);
Serial.print(", stage3StepTime=");
Serial.print(this->stage3StepTime);
Serial.print(", stepTime=");
Serial.print(this->stepTime);
Serial.print(", currentTimestamp=");
Serial.println(time);
}
// call the step method to rotate the motor
this->step();
}
}
void EasyStepper::stop()
{
this->stepsToGo = 0;
this->done = true;
}
void EasyStepper::run()
{
// the current timestamp
unsigned long time = micros();
if (!this->done && time >= this->nextTimestamp)
{
this->step();
}
if (this->debugModeFlag)
{
Serial.print("currentTimeStamp=");
Serial.println(time);
}
}
void EasyStepper::step()
{
// are there some steps to rotate?
if (this->stepsToGo > this->stepsGone)
{
// HIGH value
digitalWrite(stepPin, HIGH);
// delay
delayMicroseconds(2);
// LOW value
digitalWrite(stepPin, LOW);
// increase the stepsGone
this->stepsGone++;
// default: stage2
float nextStepTime = this->stepTime;
if (this->acceleration != 0)
{
if (this->stepsGone < this->stage1)
{
// stage1: down to stepTime from startTime
nextStepTime = this->startTime - this->stage1StepTime * this->stepsGone;
}
else if (this->stepsGone >= this->stage2)
{
// stage3: up to startTime from stepTime
nextStepTime = this->stepTime + this->stage3StepTime * (this->stepsGone - this->stage2 + 1);
}
}
// current timestamp
unsigned long time = micros();
this->nextTimestamp = time + nextStepTime;
if (this->debugModeFlag)
{
Serial.print("step: stepsGone=");
Serial.print(this->stepsGone);
Serial.print(", currentTimestamp=");
Serial.print(time);
Serial.print(", nextTimestamp=");
Serial.print(this->nextTimestamp);
Serial.print(", nextStepTime=");
Serial.println(nextStepTime);
}
}
else
{
this->done = true;
}
}
boolean EasyStepper::isDone()
{
return this->done;
}

復(fù)制代碼

ID:158981 · 發(fā)表于 2018-3-30 12:44

ID:158981 · 發(fā)表于 2018-3-30 19:30

angmall 發(fā)表于 2018-3-30 11:08
這段是參照網(wǎng)上編碼器讀取程序?qū)懙淖x取步進(jìn)電機(jī)控制脈沖的程序

請總工來指點(diǎn)一下，不勝感激！

ID:299646 · 發(fā)表于 2018-3-30 20:48

要有break試試

ID:299646 · 發(fā)表于 2018-3-30 20:51

可以了嗎

ID:158981 · 發(fā)表于 2018-3-31 09:26

liunian00 發(fā)表于 2018-3-30 20:51
可以了嗎

什么可以了？我就是想知道為什么if語句里面的內(nèi)容能循環(huán)執(zhí)行的？能指點(diǎn)下嗎？

ID:158981 · 發(fā)表于 2018-3-31 19:34

感謝上面各位，今天重復(fù)看了這個(gè)程序，才發(fā)現(xiàn)循環(huán)調(diào)用是要在寫程序里實(shí)現(xiàn)的，跟庫文件的內(nèi)容沒啥關(guān)系。

初學(xué)者多笑話

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請問這個(gè)庫函數(shù)程序是怎么循環(huán)執(zhí)行的？