2. Move by Code

In the previous project, we have tried to control the operation of the motor by using different level signals for the input of the L298N.

If we modify the level signals through the program, then we can control the movement of the car in a flexible way. Here we connect the pins IN1~IN4 of L298N to pins 5, 6, 9 and 10 on the R3 board in turn.

Required Components

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name	ITEMS IN THIS KIT	LINK
3 in 1 Starter Kit	380+	3 in 1 Starter Kit

You can also buy them separately from the links below.

COMPONENT INTRODUCTION	PURCHASE LINK
SunFounder R3 Board	BUY
L298N Module	BUY
TT Motor	-

Wiring

The L298N motor driver module is a high power motor driver module for driving DC and stepper motors. The L298N module can control up to 4 DC motors, or 2 DC motors with direction and speed control.

Connect the wires between the L298N module and the R3 board according to the diagram below.

L298N	R3 Board	Motor
IN1	5
IN2	6
IN3	9
IN4	10
OUT1		Black wire of right motor
OUT2		Red wire of right motor
OUT3		Black wire of left motor
OUT4		Red wire of left motor

Code

Note

• Open the 2.move.ino file under the path of 3in1-kit\car_project\2.move.

• Or copy this code into Arduino IDE.

• Or upload the code through the Arduino Web Editor.

After the code is uploaded, the car will move forward, backward, left and right for two seconds respectively.

How it works?

This project is basically the same as the previous one, which is to make the car move forward, backward, left and right and stop by giving different levels from IN1 to IN4.

1. Initialize the pin wiring of IN1~IN4.

   const int in1 = 5;
   const int in2 = 6;
   const int in3 = 9;
   const int in4 = 10;
   
   void setup() {
       pinMode(in1, OUTPUT);
       pinMode(in2, OUTPUT);
       pinMode(in3, OUTPUT);
       pinMode(in4, OUTPUT);
   }
   

2. Set IN1~IN4 to different high or low levels to control the rotation of the left and right motors, and then encapsulate them in individual functions.

   void moveForward() {
       digitalWrite(in1, LOW);
       digitalWrite(in2, HIGH);
       digitalWrite(in3, HIGH);
       digitalWrite(in4, LOW);
   }
   
   void moveBackward() {
       digitalWrite(in1, HIGH);
       digitalWrite(in2, LOW);
       digitalWrite(in3, LOW);
       digitalWrite(in4, HIGH);
   }
   ...
   

3. Call these functions in loop().

   void loop() {
       moveForward();
       delay(2000);
       stopMove();
       delay(500);
   
       moveBackward();
       delay(2000);
       stopMove();
       delay(500);
   ...
   

• digitalWrite(pin, value)

  • pin: the Arduino pin number.

  • value: HIGH or LOW.

  Write a HIGH or a LOW value to a digital pin. If the pin has been configured as an OUTPUT with pinMode(), its voltage will be set to the corresponding value: 5V (or 3.3V on 3.3V boards) for HIGH, 0V (ground) for LOW.

• pinMode(pin, mode)

  • pin: the Arduino pin number to set the mode of.

  • mode: INPUT, OUTPUT, or INPUT_PULLUP.

  Configures the specified pin to behave either as an input or an output.

• delay(ms)

  • ms: the number of milliseconds to pause. Allowed data types: unsigned long.

  Pauses the program for the amount of time (in milliseconds) specified as parameter. (There are 1000 milliseconds in a second.)