This project demonstrates how to interface and control a unipolar stepper motor with the 8051 microcontroller using ULN2003A driver IC. The motor can be rotated in Wave, Full, and Half-step modes by sending proper control signals to the motor coils.
- Rotate stepper motor using AT89S52 / 8051
- Supports Wave Drive, Full Step, and Half Step modes
- ULN2003A transistor array for current amplification
- Accurate angular positioning without feedback sensors
- Great for educational, robotics, and automation projects
| Component | Description |
|---|---|
| 8051 Microcontroller | AT89S52 or any 8051 compatible MCU |
| ULN2003A IC | 7-channel Darlington transistor array |
| Unipolar Stepper Motor | 6-wire (e.g., 28BYJ-48 or similar) |
| 12V Power Supply | For powering the motor |
| Breadboard + Jumpers | For prototyping |
| Multimeter | For identifying common wires |
- One coil energized at a time
- Lower torque and lower power consumption
- Two coils energized simultaneously
- Higher torque output
- Alternates between one and two coils
- Produces smoother rotation and higher resolution
- Motor coil wires → ULN2003A output pins
- ULN2003A input pins → P2.0 to P2.3 of 8051
- Two common wires of motor → 12V supply
- ULN2003A GND → GND
| Issue | Cause / Solution |
|---|---|
| Motor vibrates but doesn't rotate | Incorrect coil sequence or missing 12V supply |
| Motor not responding | Check driver IC, P2 port pins, and power connections |
| Incorrect direction | Reverse step sequence logic |
| Overheating components | Verify ULN2003A and supply current rating |
- CNC and 3D printers (basic motion control)
- DIY robotics arms
- Pan/Tilt camera mechanisms
- Antenna rotators and scanners
- Industrial positioning systems
- Add directional control via push buttons
- Add speed control using delay or timers
- Support for bipolar motors using L293D or A4988
- LCD display for current mode/angle
- Serial interface for mode switching
| Parameter | Value |
|---|---|
| Motor Type | Unipolar Stepper Motor (e.g., 28BYJ-48) |
| Control Interface | 4-bit (P2.0 - P2.3) |
| Step Angle | 1.8° typical (200 steps/rev) |
| Supply Voltage | 12V DC (motor) |
| Driver IC | ULN2003A |
| Drive Modes | Wave, Full Step, Half Step |
| Platform | 8051 / AT89S52 |
- 📖 Complete Tutorial on Circuit Digest
- 🔌 ULN2003A Datasheet
- 🧠 More Stepper Motor Projects
- ⚙️ 8051 Microcontroller Projects
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8051 stepper motor control • ULN2003A motor driver • wave drive mode • full step sequence • embedded C motor control • unipolar stepper 6-wire • microcontroller motor interfacing • 8051 projects • robotics with 8051 • stepper interfacing tutorial