Arduino智能小车调速

1、驱动模块接线  在前面的教程中已经讲过如果想控制驱动的输出时，需要对驱动的“ENA”“ENB”进行控制，因此我们需要将图中被选中部分的两个跳线帽拔掉。并将“ENA”连接Arduino UNO开发板的“5”引脚，“ENB”连接“6”引脚。

2、Arduino代码测试如下：int 盟敢势袂leftCounter=0, rightCounter=0;unsigned long time = 0, old_time = 0; // 时间标记unsigned long time1 = 0; // 时间标记float lv,rv;//左、右轮速度#define STOP 0#define FORWARD 1#define BACKWARD 2#define TURNLEFT 3#define TURNRIGHT 4#define CHANGESPEED 5int leftMotor1 = 16;int leftMotor2 = 17;int rightMotor1 = 18;int rightMotor2 = 19;bool speedLevel=0;int leftPWM = 5;int rightPWM = 6;void setup() { // put your setup code here, to run once: Serial.begin(9600); attachInterrupt(0,RightCount_CallBack, FALLING); attachInterrupt(1,LeftCount_CallBack, FALLING); pinMode(leftMotor1, OUTPUT); pinMode(leftMotor2, OUTPUT); pinMode(rightMotor1, OUTPUT); pinMode(rightMotor2, OUTPUT); pinMode(leftPWM, OUTPUT); pinMode(rightPWM, OUTPUT);}void loop() { // put your main code here, to run repeatedly: SpeedDetection(); if(Serial.available()>0) { char cmd = Serial.read(); Serial.print(cmd); motorRun(cmd); if(speedLevel) //根据不通的档位输出不同速度 { analogWrite(leftPWM, 120); analogWrite(rightPWM, 120); } else { analogWrite(leftPWM, 250); analogWrite(rightPWM, 250); } }}/** *速度计算*/bool SpeedDetection(){ time = millis();//以毫秒为单位，计算当前时间 if(abs(time - old_time) >= 1000) // 如果计时时间已达1秒 { detachInterrupt(0); // 关闭外部中断0 detachInterrupt(1); // 关闭外部中断1 //把每一秒钟编码器码盘计得的脉冲数，换算为当前转速值 //转速单位是每分钟多少转，即r/min。这个编码器码盘为20个空洞。 Serial.print("left:"); lv =(float)leftCounter*60/20;//小车车轮电机转速 rv =(float)rightCounter*60/20;//小车车轮电机转速 Serial.print("left:"); Serial.print(lv);//向上位计算机上传左车轮电机当前转速的高、低字节 Serial.print(" right:"); Serial.println(rv);//向上位计算机上传左车轮电机当前转速的高、低字节 //恢复到编码器测速的初始状态 leftCounter = 0; //把脉冲计数值清零，以便计算下一秒的脉冲计数 rightCounter = 0; old_time= millis(); // 记录每秒测速时的时间节点 attachInterrupt(0, RightCount_CallBack,FALLING); // 重新开放外部中断0 attachInterrupt(1, LeftCount_CallBack,FALLING); // 重新开放外部中断0 return 1; } else return 0;}/** *右轮编码器中断服务函数*/void RightCount_CallBack(){ rightCounter++;}/** *左轮编码器中断服务函数*/void LeftCount_CallBack(){ leftCounter++;}/** *小车运动控制函数*/void motorRun(int cmd){ switch(cmd){ case FORWARD: Serial.println("FORWARD"); //输出状态 digitalWrite(leftMotor1, HIGH); digitalWrite(leftMotor2, LOW); digitalWrite(rightMotor1, HIGH); digitalWrite(rightMotor2, LOW); break; case BACKWARD: Serial.println("BACKWARD"); //输出状态 digitalWrite(leftMotor1, LOW); digitalWrite(leftMotor2, HIGH); digitalWrite(rightMotor1, LOW); digitalWrite(rightMotor2, HIGH); break; case TURNLEFT: Serial.println("TURN LEFT"); //输出状态 digitalWrite(leftMotor1, HIGH); digitalWrite(leftMotor2, LOW); digitalWrite(rightMotor1, LOW); digitalWrite(rightMotor2, HIGH); break; case TURNRIGHT: Serial.println("TURN RIGHT"); //输出状态 digitalWrite(leftMotor1, LOW); digitalWrite(leftMotor2, HIGH); digitalWrite(rightMotor1, HIGH); digitalWrite(rightMotor2, LOW); break; case CHANGESPEED: Serial.println("CHANGE SPEED"); //输出状态 if(speedLevel) //接收到换挡命令的时候切换档位 speedLevel=0; else speedLevel=1; break; default: Serial.println("STOP"); //输出状态 digitalWrite(leftMotor1, LOW); digitalWrite(leftMotor2, LOW); digitalWrite(rightMotor1, LOW); digitalWrite(rightMotor2, LOW); }}

3、为了便于大家理解，这里特意在解释一下： 在主函数void loop()中添加PWM输出的函数，analogWrite(pin, value)函数中“pin”代表使用的引脚，“value”代表输出PWM值的大小，范围是0~255。if(speedLevel) //根据不通的档位输出不同速度 { analogWrite(leftPWM, 120); analogWrite(rightPWM, 120); } else { analogWrite(leftPWM, 250); analogWrite(rightPWM, 250); }