The 28BYJ-48 is a compact and widely used 5V unipolar stepper motor designed for precise position and speed control in low-power applications. With an integrated gearbox, it delivers high torque at low speeds, making it ideal for robotics, automation, and educational projects.
Core Motor Specifications
• Motor Type: Unipolar stepper motor
• Model: 28BYJ-48
• Rated Voltage: 5 V DC
• Number of Phases: 4
• Gear Reduction Ratio: 1:64 (typical)
Electrical & Interface
• Operating Voltage: 5 V
• Coil Resistance: ~50 Ω per phase
• Drive Method: Unipolar
• Connector Type: 5-pin JST
• Compatible Driver: ULN2003 stepper driver module
Performance Characteristics
• Step Angle (Motor): 5.625°
• Step Angle (After Gearbox): ~0.0879°
• Steps per Revolution: 4096 (with gearbox)
• Torque: High torque at low speed (gearbox assisted)
• Speed: Best suited for low to moderate speed applications
Physical Characteristics
• Body Type: Round can-style stepper motor
• Shaft Type: Plastic geared output shaft
• Mounting: Front flange with screw holes
• Compact and lightweight design
Compatibility
• Arduino Uno / Nano / Mega
• ESP8266 / ESP32
• STM32, AVR, PIC microcontrollers
• Raspberry Pi (via driver module)
Key Advantages
• Precise position control with repeatable steps
• Integrated gearbox increases torque
• Low-cost and beginner-friendly stepper motor
• Widely supported by libraries and examples
Technical Insights
• Requires a driver (ULN2003) for safe operation
• Gearbox introduces slight backlash, not ideal for high-precision CNC
• Can be converted to bipolar mode with wiring modification
• Works best with step delays for smooth motion
Applications
• Robotic arms and joints
• Camera pan-tilt mechanisms
• Small automation systems
• Educational robotics projects
• Smart locks and dials
Pro Tip
• Always use a ULN2003 driver instead of driving directly from GPIO
• Use half-step mode for smoother and quieter motion
• Avoid high-speed rotation to prevent missed steps
Package Includes
• 1 × 28BYJ-48 5V Stepper Motor