L298N Module

ARDUINO MODULE DUAL H-BRIDGE MOTOR CONTROLLER

H-Bridge’s are typically used in controlling motors speed and direction, but can be used for other projects such as driving the brightness of certain lighting projects such as high powered LED arrays.

How it works:

An H-Bridge is a circuit that can drive a current in either polarity and be controlled by *Pulse Width Modulation (PWM).

* Pulse Width Modulation is a means in controlling the duration of an electronic pulse. In motors try to imagine the brush as a water wheel and electrons as a the flowing droplets of water. The voltage would be the water flowing over the wheel at a constant rate, the more water flowing the higher the voltage. Motors are rated at certain voltages and can be damaged if the voltage is applied to heavily or if it is dropped quickly to slow the motor down. Thus PWM. Take the water wheel analogy and think of the water hitting it in pulses but at a constant flow. The longer the pulses the faster the wheel will turn, the shorter the pulses, the slower the water wheel will turn. Motors will last much longer and be more reliable if controlled through PWM.

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Pins:

  • Out 1: Motor A lead out
  • Out 2: Motor A lead out
  • Out 3: Motor B lead out
  • Out 4: Mo (Can actually be from 5v-35v, just marked as 12v)
  • GND: Ground
  • 5v: 5v input (unnecessary if your power source is 7v-35v, if the power source is 7v-35v then it can act as a 5v out)
  • EnA: Enables PWM signal for Motor A (Please see the “Arduino Sketch Considerations” section)
  • In1: Enable Motor A
  • In2: Enable Motor A
  • In3: Enable Motor B
  • In4: Enable Motor B
  • EnB: Enables PWM signal for Motor B (Please see the “Arduino Sketch Considerations” section)

Specifications:

  • Double H bridge Drive Chip: L298N
  • Logical voltage: 5V Drive voltage: 5V-35V
  • Logical current: 0-36mA Drive current: 2A (MAX single bridge)
  • Max power: 25W
  • Dimensions: 43 x 43 x 26mm
  • Weight: 26g

 

 

Two things to mention;

  • Make sure you have all of your grounds tied together; Arduino, Power source, and the Motor controller.
  • The PWM Pins are unnecessary if you do not want to control PWM features.

 

 

The Arduino code sketch is pretty straight forward. Since there isn’t a library for the L298N Dual H-Bridge Motor Controller you just have to declare which pins the controller is hooked to.

The “int dir(number)Pin(letter)”‘ pins can be connected to any available digital pin you have available, as long as you declare the correct pin in your sketch. This makes the L298N Dual H-Bridge Motor Controller very versatile if your project is using a lot of Arduino pins.

The int“speedPin(letter)” pins need to be connected to a PWM pin on the Arduino if you want to enable speed control through PWM.

This is a list of PWM pins for the main two types of Arduino’s:

  • AT MEGA – PWM: 2 to 13 and 44 to 46. Provide 8-bit PWM output with the analogWrite() function.
  • UNO – PWM: 3, 5, 6, 9, 10, and 11. Provide 8-bit PWM output with the analogWrite() function.

Arduino Sketch Example:

//Code by Reichenstein7 (thejamerson.com)

//Keyboard Controls:
//
// 1 -Motor 1 Left
// 2 -Motor 1 Stop
// 3 -Motor 1 Right
//
// 4 -Motor 2 Left
// 5 -Motor 2 Stop
// 6 -Motor 2 Right

// Declare L298N Dual H-Bridge Motor Controller directly since there is not a library to load.

// Motor 1
int dir1PinA = 2;
int dir2PinA = 3;
int speedPinA = 9; // Needs to be a PWM pin to be able to control motor speed

// Motor 2
int dir1PinB = 4;
int dir2PinB = 5;
int speedPinB = 10; // Needs to be a PWM pin to be able to control motor speed

void setup() { // Setup runs once per reset
// initialize serial communication @ 9600 baud:
Serial.begin(9600);

//Define L298N Dual H-Bridge Motor Controller Pins

pinMode(dir1PinA,OUTPUT);
pinMode(dir2PinA,OUTPUT);
pinMode(speedPinA,OUTPUT);
pinMode(dir1PinB,OUTPUT);
pinMode(dir2PinB,OUTPUT);
pinMode(speedPinB,OUTPUT);

}

void loop() {

// Initialize the Serial interface:

if (Serial.available() > 0) {
int inByte = Serial.read();
int speed; // Local variable

switch (inByte) {

//______________Motor 1______________

case '1': // Motor 1 Forward
analogWrite(speedPinA, 255);//Sets speed variable via PWM 
digitalWrite(dir1PinA, LOW);
digitalWrite(dir2PinA, HIGH);
Serial.println("Motor 1 Forward"); // Prints out “Motor 1 Forward” on the serial monitor
Serial.println(" "); // Creates a blank line printed on the serial monitor
break;

case '2': // Motor 1 Stop (Freespin)
analogWrite(speedPinA, 0);
digitalWrite(dir1PinA, LOW);
digitalWrite(dir2PinA, HIGH);
Serial.println("Motor 1 Stop");
Serial.println(" ");
break;

case '3': // Motor 1 Reverse
analogWrite(speedPinA, 255);
digitalWrite(dir1PinA, HIGH);
digitalWrite(dir2PinA, LOW);
Serial.println("Motor 1 Reverse");
Serial.println(" ");
break;

//______________Motor 2______________

case '4': // Motor 2 Forward
analogWrite(speedPinB, 255);
digitalWrite(dir1PinB, LOW);
digitalWrite(dir2PinB, HIGH);
Serial.println("Motor 2 Forward");
Serial.println(" ");
break;

case '5': // Motor 1 Stop (Freespin)
analogWrite(speedPinB, 0);
digitalWrite(dir1PinB, LOW);
digitalWrite(dir2PinB, HIGH);
Serial.println("Motor 2 Stop");
Serial.println(" ");
break;

case '6': // Motor 2 Reverse
analogWrite(speedPinB, 255);
digitalWrite(dir1PinB, HIGH);
digitalWrite(dir2PinB, LOW);
Serial.println("Motor 2 Reverse");
Serial.println(" ");
break;

default:
// turn all the connections off if an unmapped key is pressed:
for (int thisPin = 2; thisPin < 11; thisPin++) {
digitalWrite(thisPin, LOW);
}
 }
 }
 }

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