課程目標(biāo)

• 最簡小車的設(shè)計
• 雙電機(jī)控制車輛運(yùn)動
• 小車的多種運(yùn)動形態(tài)實(shí)現(xiàn)

電路搭建

所需材料

ArduinoUNO * 1
L298N驅(qū)動模塊 * 1
直流電機(jī) * 2
7~12V外接電源 * 1
杜邦線若干
小車組件

電路連接

程序編寫

練習(xí)一：小車的循環(huán)運(yùn)動

通過編寫程序，循環(huán)實(shí)現(xiàn)小車的前進(jìn)一秒、后退一秒、左轉(zhuǎn)一秒、右轉(zhuǎn)一秒、停止一秒功能。

圖形化方式：

如果有同學(xué)發(fā)現(xiàn)，按照下面的程序上傳后，小車的運(yùn)動有問題，那么可以通過改變直流電機(jī)的接線或者修改數(shù)字輸出引腳的高低電平即可。

代碼方式：

/* 項(xiàng)目名稱:循環(huán)控制小車運(yùn)動
 * 項(xiàng)目時間:2022.03.28
 * 項(xiàng)目作者:MRX
 */
int IN1 = 4;   // IN1連接 D4
int IN2 = 5;   
int ENA = 9; 
int IN3 = 6;   // IN3連接D6
int IN4 = 7;   
int ENB = 10; 

unsigned long delaytime = 1000;  //等待時間
int value = 100;   // 模擬輸出的值


//前進(jìn)
void forward() {
  digitalWrite(IN1,HIGH);
  digitalWrite(IN2,LOW);
  analogWrite(ENA,value);
  digitalWrite(IN3,HIGH);
  digitalWrite(IN4,LOW);
  analogWrite(ENB,value);
}


//后退
void back() {
  digitalWrite(IN1,LOW);
  digitalWrite(IN2,HIGH);
  analogWrite(ENA,value);
  digitalWrite(IN3,LOW);
  digitalWrite(IN4,HIGH);
  analogWrite(ENB,value);
}


//右轉(zhuǎn)
void right() {
  digitalWrite(IN1,LOW);
  digitalWrite(IN2,HIGH);
  analogWrite(ENA,value);
  digitalWrite(IN3,LOW);
  digitalWrite(IN4,HIGH);
  analogWrite(ENB,0);
}


//左轉(zhuǎn)
void left() {
  digitalWrite(IN1,LOW);
  digitalWrite(IN2,HIGH);
  analogWrite(ENA,0);
  digitalWrite(IN3,LOW);
  digitalWrite(IN4,HIGH);
  analogWrite(ENB,value);
}


// 停止
void stop() {
  digitalWrite(IN1,LOW);
  digitalWrite(IN2,LOW);
  analogWrite(ENA,0);
  digitalWrite(IN3,LOW);
  digitalWrite(IN4,LOW);
  analogWrite(ENB,0);
}


void setup(){
    for (int i = 4;i <= 10;i++){
      pinMode(i, OUTPUT);
    }
}

void loop(){
    forward();
    delay(delaytime);
    forward();
    delay(delaytime);
    left();
    delay(delaytime);
    right();
    delay(delaytime);
    stop();
    delay(delaytime);
}

練習(xí)二：可調(diào)速的小車

通過讀取可調(diào)電位器的值，來實(shí)現(xiàn)車速的變化。

電路接線：

在上圖的基礎(chǔ)上，增加一個可調(diào)電位器連接到UNO的A0腳。

圖形化方式：

代碼方式：

/* 項(xiàng)目名稱:電位器控制小車速度
 * 項(xiàng)目時間:2022.03.28
 * 項(xiàng)目作者:MRX
 */
int IN1 = 4;   // IN1 connected to pin 4
int IN2 = 5;   
int ENA = 9; 
int IN3 = 6;   // IN3 connected to pin 6
int IN4 = 7;   
int ENB = 10; 

unsigned long delaytime = 1000;  //delay time
int value = 0;   // the duty cycle


void forward() {
  digitalWrite(IN1,HIGH);
  digitalWrite(IN2,LOW);
  analogWrite(ENA,value);
  digitalWrite(IN3,HIGH);
  digitalWrite(IN4,LOW);
  analogWrite(ENB,value);
}


void back() {
  digitalWrite(IN1,LOW);
  digitalWrite(IN2,HIGH);
  analogWrite(ENA,value);
  digitalWrite(IN3,LOW);
  digitalWrite(IN4,HIGH);
  analogWrite(ENB,value);
}


void right() {
  digitalWrite(IN1,LOW);
  digitalWrite(IN2,HIGH);
  analogWrite(ENA,100);
  digitalWrite(IN3,LOW);
  digitalWrite(IN4,HIGH);
  analogWrite(ENB,0);
}


void left() {
  digitalWrite(IN1,LOW);
  digitalWrite(IN2,HIGH);
  analogWrite(ENA,0);
  digitalWrite(IN3,LOW);
  digitalWrite(IN4,HIGH);
  analogWrite(ENB,100);
}


void stop() {
  digitalWrite(IN1,LOW);
  digitalWrite(IN2,LOW);
  analogWrite(ENA,0);
  digitalWrite(IN3,LOW);
  digitalWrite(IN4,LOW);
  analogWrite(ENB,0);
}


void setup(){
    for (int i = 4;i <= 10;i++){
      pinMode(i, OUTPUT);
    }
    pinMode(A0,INPUT);
}

void loop(){
    value = (map(analogRead(A0), 0, 1023, 0, 255));
    forward();
}