---
tags: Arduino
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# Arduino 自走車

## Audino mega 2560

## L298P motor shield

不錯的介紹:
https://protosupplies.com/product/l298p-motor-driver-shield/

## 線路連接
- 馬達
- Motor b-/Motor b+ 接自走車左側馬達
- Motor a-/Motor a+ 接自走車右側馬達
- Motor control a 接 D10/D12 pin
- Motor control b 接 D11/D13 pin

- 超音波感測器
- Triggrr 接D7 pin
- Echo 接D8 pin

- Buzzer
- 接D4

## 完整接線圖

## 程式

int M1 = 10; //enable right whell
int E1 =12;  //high；forward
int M2 =11;  //enable left whell                     
int E2 = 13; //high:forward

int BUZZER =4;

int TRIGGER_OUT=7;
int ECHO_IN=8;


long ultrasonic_rangefinder()
{
  digitalWrite(TRIGGER_OUT, HIGH);     // 給 Trig 高電位，持續 10微秒
  delayMicroseconds(10);
  digitalWrite(TRIGGER_OUT, LOW);

  long duration = pulseIn(ECHO_IN, HIGH);   
 
  long cm = (duration/2) / 29.1;         
  return(cm);
}



void motor_forward()
{
  digitalWrite(M1,HIGH);
  digitalWrite(E1,HIGH);
  digitalWrite(M2,HIGH);
  digitalWrite(E2,HIGH);
}

void motor_stop()
{
  digitalWrite(M1,LOW);
  digitalWrite(M2,LOW);
}


void motor_backward()
{
  digitalWrite(M1,HIGH);
  digitalWrite(E1,LOW);
  digitalWrite(M2,HIGH);
  digitalWrite(E2,LOW);
}

void setup() {
  // put your setup code here, to run once:

  Serial.begin(9600);

  //initial motor
  pinMode(M1, OUTPUT); 
  pinMode(E1, OUTPUT);
  pinMode(M2, OUTPUT);
  pinMode(E2, OUTPUT);

  //initial buzzer
  pinMode(BUZZER,OUTPUT);

  //initial ultrasonic rangefinder
  pinMode(TRIGGER_OUT,OUTPUT);
  pinMode(ECHO_IN,INPUT);

  //motor stop
  digitalWrite(M1,LOW);
  digitalWrite(M2,LOW);

  //buzzer off
  digitalWrite(BUZZER,LOW);

  //ultrasonic rangefinder off
  digitalWrite(TRIGGER_OUT,LOW);
  
}

void loop() {
  // put your main code here, to run repeatedly:
  
  long dist,dist1,dist2;

  delay(50);
  
  dist1=ultrasonic_rangefinder();
  dist2=ultrasonic_rangefinder();
  dist=(dist1+dist2)/2;
  
  Serial.print(dist);
  Serial.print(" ");
  if(dist>50)
  {
    motor_forward();
    digitalWrite(BUZZER,LOW);
  }
  else if(dist<20)
  {
    motor_backward();
    digitalWrite(BUZZER,HIGH);
  }
} 

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{%youtube kPZBUO3W380 %}

## 問題
- 齒輪轉動好像有偏心
-重新調整齒輪嗎?
- 輪子走得不快,不知是否正常
-換馬達嗎?驅動晶片模組?

## 不錯的文章

https://jk3527101.pixnet.net/blog/post/14108743

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## 連接藍芽模組(HC-05/HC-06)

藍芽模組的LED燈號:
連續的快閃：
藍芽等待配對中。--->bluetooth板子的EN腳接地 --->手機可搜尋到裝置
連續的快閃2下後停1下：
藍芽已配對成功，運作中。
連續慢速閃爍(約兩秒一次)：
藍芽已進入AT模式，準備設定。 -->-->bluetooth板子的EN腳3.3V

裡面有講到細節:
https://swf.com.tw/?p=712

程式摘要:

#include <SoftwareSerial.h>

SoftwareSerial BT(2,3);  //接收,傳送 模組的RX接於 MMega2560 的第3腳

BT.begin(9600);

BT.print("xxx");

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