Stepper Motor Driver ULN2003 Green

Features:

1. Reverse Voltage Protection: Built-in diodes protect against reverse voltage, preventing damage from voltage spikes or incorrect polarity.
2. Higher Efficiency: Improved efficiency compared to the original version, resulting in lower heat generation and better performance.
3. Low Power Consumption: Ideal for battery-powered applications.
4. Onboard Connector: Designed to perfectly fit stepper motor wires for easy connection.
5. LED Indicators: Four LEDs show activity on the control input lines, making debugging easier.

Description:

The green ULN2003 motor driver board is an efficient and reliable solution for driving stepper motors. It includes built-in diodes for reverse voltage protection, which extends the lifespan and reliability of the driver. It operates in the 5V to 12V range, making it compatible with various power sources. The onboard connector simplifies motor wiring, while the LEDs provide visual feedback of motor stepping states.

Principle of Operation:

When a microcontroller sends signals to the ULN2003 module, it activates one of the Darlington transistor pairs inside the IC. Each pair amplifies the input signal to provide a higher current output needed to drive the motor coils. The module has four control inputs (IN1 to IN4) connected to the microcontroller, controlling the direction and steps of the motor. Flyback diodes protect the module from voltage spikes caused by motor coil inductance.

Pinout:

• IN1: Control input for motor phase 1
• IN2: Control input for motor phase 2
• IN3: Control input for motor phase 3
• IN4: Control input for motor phase 4
• +5V: Power supply input (5V DC)
• GND: Ground
• Motor A: Motor coil connection A
• Motor B: Motor coil connection B

Applications:

• Robotics – controlling precise movements of robotic arms and components
• CNC machines – driving stepper motors for cutting and milling
• 3D printers – controlling motors for additive manufacturing
• Industrial automation – conveyor belts, packaging, assembly lines
• Camera sliders – smooth motion control in video production
• Telescope mounts – precise tracking of celestial objects

Circuit Example:

Connect Arduino pins 8, 9, 10, and 11 to ULN2003 inputs IN1, IN2, IN3, and IN4 respectively. Use an external 5V power source connected to the module’s +5V and GND (common ground with Arduino recommended).

Library:

No extra library needed; use the built-in Stepper.h library in the Arduino IDE.

Example Code:

// Stepper motor control with ULN2003 driver and Arduino
#include <Stepper.h>

// Number of steps per revolution for 28BYJ-48 motor
const int stepsPerRevolution = 2048;

// Initialize the stepper motor (pin order: 11, 10, 9, 8)
Stepper myStepper(stepsPerRevolution, 11, 10, 9, 8);

void setup() {
  myStepper.setSpeed(10); // RPM
  Serial.begin(9600);
}

void loop() {
  if (Serial.available()) {
    char command = Serial.read();
    switch (command) {
      case 'F':
        Serial.println("Moving forward");
        myStepper.step(stepsPerRevolution / 4);
        break;
      case 'B':
        Serial.println("Moving backward");
        myStepper.step(-stepsPerRevolution / 4);
        break;
      case 'S':
        Serial.println("Stopping");
        myStepper.step(0);
        break;
      default:
        Serial.println("Invalid command");
    }
  }
}

Technical Details:

• ULN2003A motor driver chip
• All pins broken out for easy connection
• Power supply: 5V - 12V
• Signal indicators: 4 LEDs
• XH-5P socket compatible with 28BYJ-48 stepper motor
• PCB size: 40.5 × 21.3 mm

Comparison with A4988 Driver:

• Current Handling: A4988 supports up to 2A, ULN2003 up to 0.5A.
• Microstepping: A4988 supports microstepping for smooth control; ULN2003 does not.
• Heat Dissipation: A4988 generates more heat, may need cooling.
• Cost: ULN2003 is more affordable, suitable for low-power projects.

When to Use:

• ULN2003: Best for low-power, simple stepper motor applications and hobby projects.
• A4988: Ideal for high-current, precise control applications like 3D printers and CNC machines.