MOSFETs, or Metal-Oxide-Semiconductor Field-Effect Transistors, are essential components in electronic circuits. They are widely used in Arduino projects to control high-power devices such as motors, lights, and solenoids. MOSFETs offer a low-resistance path for current flow when properly driven by an Arduino microcontroller. This article will explain the basics of MOSFETs, their importance in Arduino projects, and provide code examples to help you get started.

Project: Controlling a DC Motor using MOSFET

In this example project, we will use an Arduino to control the speed and direction of a DC motor using a MOSFET. The objective is to create a simple motor control system that can be easily adapted for various applications.

Components List:

• Arduino Uno (1)
• MOSFET (1) - IRF520 or similar
• DC Motor (1)
• Diode (1) - 1N4001 or similar
• Resistor (1) - 220 ohm
• Breadboard and jumper wires

Examples:

// Pin definitions
const int motorPin = 9;

void setup() {
  pinMode(motorPin, OUTPUT);
}

void loop() {
  // Set motor speed to half power
  analogWrite(motorPin, 128);
  delay(2000); // Wait for 2 seconds

  // Stop the motor
  analogWrite(motorPin, 0);
  delay(1000); // Wait for 1 second

  // Reverse motor direction
  digitalWrite(motorPin, HIGH);
  delay(2000); // Wait for 2 seconds

  // Stop the motor
  digitalWrite(motorPin, LOW);
  delay(1000); // Wait for 1 second
}

Code Explanation:

• We start by defining the pin connected to the MOSFET gate as motorPin (pin 9 in this example).
• In the setup() function, we set motorPin as an output.
• Inside the loop() function, we use the analogWrite() function to control the speed of the motor. The value passed to analogWrite() can range from 0 (off) to 255 (full power).
• We set the motor speed to half power (128) and wait for 2 seconds using delay().
• Then, we stop the motor by setting the motor speed to 0 and wait for 1 second.
• Next, we reverse the motor direction by setting motorPin to HIGH and wait for 2 seconds.
• Finally, we stop the motor again by setting motorPin to LOW and wait for 1 second.