### 4.3.14 IR Remote Control Robot 

#### 4.3.14.1 Introduction

![Img](./media/img-20251217105603.png)

In this project, we will make IR remote control robot car!
Press the button on IR remote control to drive robot car to move, and the corresponding state pattern is displayed on the 8*16 LED matrix.

The specific logic of IR remote control robot car is shown below:

![Img](./media/img-20251217105827.png)

![Img](./media/img-20251217105835.png)

#### 4.3.14.2 Wiring Diagram

1. GND, VCC, SDA and SCL of the 8*8 dot matrix module are connected to G（GND), V（VCC), A4 and A5 of the expansion board.

2. Since the Keyestudio 8833 motor driver expansion board integrates the IR receiver, pins of the IR receiver are G（GND), V（VCC）and D3
3. The power is connected to the BAT port

⚠️ **Attention: You do not need to disassemble the Smart Little Turtle Robot and re-connect the module. Here this disgram will be convenient for you to program and write code.**

![Img](./media/img-20251217105909.png)

#### 4.3.14.3 Test Code

```c++
/*
keyestudio smart turtle robot 
lesson 14
remote control turtle
http://www.keyestudio.com
*/ 
#include <ks_Matrix.h>
Matrix myMatrix(A4,A5);
//Array, used to store the data of pattern, can be calculated by yourself or obtained from the modulus tool
uint8_t matrix_heart[8]={0x66,0x99,0x81,0x81,0x42,0x24,0x18,0x00};
uint8_t matrix_smile[8]={0x42,0xa5,0xa5,0x00,0x00,0x24,0x18,0x00};
uint8_t matrix_front2[8]={0x18,0x24,0x42,0x99,0x24,0x42,0x81,0x00};
uint8_t matrix_back2[8]={0x00,0x81,0x42,0x24,0x99,0x42,0x24,0x18};
uint8_t matrix_left2[8]={0x12,0x24,0x48,0x90,0x90,0x48,0x24,0x12};
uint8_t matrix_right2[8]={0x48,0x24,0x12,0x09,0x09,0x12,0x24,0x48};
uint8_t matrix_stop2[8]={0x18,0x18,0x18,0x18,0x18,0x00,0x18,0x18};
uint8_t  LEDArray[8];
const int left_ctrl = 4;//define the direction control pin of A motor
const int left_pwm = 6;//define the speed control of A motor
const int right_ctrl = 2;//define the direction control pin of B motor 
const int right_pwm = 5;//define the speed control pin of B motor 
#include <IRremote.h>//function library of IR remote control
int RECV_PIN = 3;//set the pin of IR receiver to D3
IRrecv irrecv(RECV_PIN);
long irr_val;
decode_results results;

void setup()
{
  pinMode(left_ctrl,OUTPUT);//
  pinMode(left_pwm,OUTPUT);//
  pinMode(right_ctrl,OUTPUT);//
  pinMode(right_pwm,OUTPUT);//
    Serial.begin(9600);//
  // In case the interrupt driver crashes on setup, give a clue
  // to the user what's going on.
  Serial.println("Enabling IRin");
  irrecv.enableIRIn(); // Start the receiver
  Serial.println("Enabled IRin");
  myMatrix.begin(112);
  myMatrix.clear();
  myMatrix.writeDisplay();
  matrix_display(matrix_smile); 
}
void loop()
 {
  if (irrecv.decode(&results)) 
 {
    irr_val = results.value;
    Serial.println(irr_val, HEX);//serial prints the read IR remote signals 
    switch(irr_val)
    {
      case 0xFF629D : car_front(); 
      myMatrix.clear();
      myMatrix.writeDisplay();
      matrix_display(matrix_front2);  
      break;
      
      case 0xFFA857 : car_back(); 
      myMatrix.clear();
      myMatrix.writeDisplay();
      matrix_display(matrix_back2); 
      break;
      case 0xFF22DD : car_left(); 
      myMatrix.clear();
      myMatrix.writeDisplay();
      matrix_display(matrix_left2); 
      break;
     
      case 0xFFC23D : car_right();
      myMatrix.clear();
      myMatrix.writeDisplay();
      matrix_display(matrix_right2); 
      break;
     
      case 0xFF02FD : car_Stop();
      myMatrix.clear();
      myMatrix.writeDisplay();
      matrix_display(matrix_stop2); 
      break;
    }
        irrecv.resume(); // Receive the next value
  }
}
void car_front()//define the state of going front
{
  digitalWrite(left_ctrl,HIGH);
  analogWrite(left_pwm,155);
  digitalWrite(right_ctrl,HIGH);
  analogWrite(right_pwm,155);
}
void car_back()//define the status of going back
{
  digitalWrite(left_ctrl,LOW);
  analogWrite(left_pwm,100);
  digitalWrite(right_ctrl,LOW);
  analogWrite(right_pwm,100);
}
void car_left()//set the status of left turning
{
  digitalWrite(left_ctrl,LOW);
  analogWrite(left_pwm,100);
  digitalWrite(right_ctrl,HIGH);
  analogWrite(right_pwm,155);
}
void car_right()//set the status of right turning
{
  digitalWrite(left_ctrl,HIGH);
  analogWrite(left_pwm,155);
  digitalWrite(right_ctrl,LOW);
  analogWrite(right_pwm,100);
}
void car_Stop()//define the state of stop
{
  digitalWrite(left_ctrl,LOW);
  analogWrite(left_pwm,0);
  digitalWrite(right_ctrl,LOW);
  analogWrite(right_pwm,0);
}
//The function that dot matrix shows pattern
void matrix_display(unsigned char matrix_value[])
{
  for(int i=0; i<8; i++)
    {
      LEDArray[i]=matrix_value[i];
      for(int j=7; j>=0; j--)
      {
        if((LEDArray[i]&0x01)>0)
        myMatrix.drawPixel(j, i,1);
        LEDArray[i] = LEDArray[i]>>1;
      }
    } 
    myMatrix.writeDisplay();
}
```

#### 4.3.14.4 Test Result

Upload code power on the external power, turn the DIP switch to ON and press buttons on IR remote control. The turtle robot car will follow the obstacle to move.