Boardoza ULN2003A Unipolar Stepper Motor Driver Breakout Board
The Boardoza ULN2003A Stepper Motor Driver Breakout Board is a four-channel motor control board based on the Texas Instruments ULN2003ADR Darlington transistor array. It supports a unipolar stepper motor, four unidirectional DC motors or two bidirectional DC motors. For unipolar stepper applications, a host microcontroller controls direction and speed by applying full-step or half-step patterns to IN1–IN4.
The outputs can also switch relay coils, solenoids and lamps. Four output indicator LEDs show driver activation, while integrated flyback clamp diodes provide an inductive-current return path to VCC. A power indicator, supply decoupling capacitors and a supply selection header support integration into motor control projects. This documentation covers a nominal 5 V supply configuration.

Key Features
- Four-channel unipolar stepper motor drive.
- Full-step and half-step operation with host sequencing.
- Supports four unidirectional or two bidirectional DC motors.
- Integrated flyback clamp diodes connected to VCC.
- TTL and 5 V CMOS control inputs.
- Four output indicators and one power LED.
- Jumper-selectable supply source.
- Screw terminals for loads and supply connections.
Technical Specifications
- Item
- ULN2003ADR
- Input Voltage
- 5V nominal
- Functions
- DC load switching
- Output Current
- 500 mA/channel
- Number of Channels
- 4
- Operating Temperature
- -40/+70 °C
- Board Dimensions
- 40x40mm
Support
For technical questions, documentation and issue reports, use the GitHub repository or write to us directly.
