28BYJ-48 Stepper Motor and ULN2003 Stepper Motor Driver

28BYJ-48 Stepper Motor and ULN2003 Stepper Motor Driver provides an ideal entry point for engineers and hobbyists looking to implement precise motion control in their electronic projects. This compact unit combines a 5V geared unipolar stepper motor with a high-current Darlington transistor array driver, which simplifies the interface between low-power microcontrollers and the motor coils. Furthermore, the internal gear reduction ratio ensures high torque and fine step resolution, making it perfect for applications requiring accuracy rather than high speed. Consequently, you can achieve sophisticated positioning tasks with minimal programming effort. Therefore, this kit stands as a staple component for automated blinds, robotics, and rotating sensor platforms.

Key Features:

• High Torque Output: The internal 64:1 gear reduction ratio significantly multiplies the torque, allowing the small motor to move substantial loads.
• Easy Interface: The ULN2003 driver board features four signal LEDs, which provide immediate visual feedback of the stepping sequence during operation.
• Plug-and-Play Design: A pre-wired 5-pin JST connector links the motor directly to the driver board, eliminating the risk of incorrect wiring.
• Precision Positioning: Utilizing a 4-step or 8-step sequence allows for fine control over the rotation angle and speed.
• Low Power Operation: Optimized for 5V DC, this system works seamlessly with standard USB power sources and microcontroller development boards.

Technical Specifications:

• Rated Voltage: 5 V DC
• Number of Phases: 4 Phases (Unipolar)
• Stride Angle: 5.625° / 64 (approximately 0.088° per step at output shaft)
• Reduction Ratio: 1/64
• DC Resistance: 50 Ω ±7% (at 25°C)
• Pull-in Torque: ≥ 300 gf.cm (at 100Hz)
• Driver IC: ULN2003A Darlington Array
• Insulation Resistance: ≥ 10 MΩ (500V)

Mechanical Specifications:

• Shaft Type: Flatted D-shaft for secure attachment of gears and pulleys.
• Noise Level: ≤ 35 dB (at 100Hz, No load)
• Mounting Holes: Dual integrated tabs with ≈ 4.2 mm diameter holes.
• Driver Board Mounting: Four M3-compatible mounting holes located at the corners.

Dimensions:

• Motor Diameter: 28 mm
• Motor Height: 19 mm (excluding shaft)
• Shaft Diameter: 5 mm
• Shaft Length: ≈ 8 mm
• Driver Board Dimensions: ≈ 31 mm x 35 mm

Pinout and Wiring:

• IN1 – IN4: Connect these inputs to four digital output pins on your microcontroller (e.g., Arduino pins 8, 9, 10, 11).
• VCC/GND: Connect to an external 5V power supply to ensure the motor receives adequate current.
• Motor Header: Connect the 5-pin female connector from the 28BYJ-48 motor to the white male header on the driver.
• Jumper (On/Off): Provides power to the motor; removing it effectively disables the motor while keeping the logic active.

Datasheet Reference:

• Download 28BYJ-48 and ULN2003 Datasheet

Commonly Used in:

• Arduino Projects: Used extensively in academic kits to teach the fundamentals of unipolar stepper motor driving.
• Robotic Arms: Provides the articulation for joints where precise movement is more critical than rapid speed.
• DIY CNC Machines: Serves as a low-cost actuator for small-scale drawing robots or laser engravers.

Applications:

• Automatic Ventilation: Driving the louvers in air conditioning units or smart window vents.
• Camera Pan/Tilt: Rotating security cameras or phone mounts for panoramic photography.
• Precision Valve Control: Regulating the flow of liquids in small-scale laboratory automation.

Equivalent Models:

• 12V 28BYJ-48: A higher voltage variant designed for systems using 12V rails, however, it requires a compatible driver voltage.
• NEMA 17 (with appropriate driver): A more powerful alternative, consequently requiring a different control philosophy and higher current.
• MP24GA: A functionally similar geared stepper motor often found in HVAC applications.

Package Includes:

• 1 x 28BYJ-48 5V Stepper Motor
• 1 x ULN2003 Stepper Motor Driver Board