Lesson 8. Arduino Nano. Stepper motor 28BYJ‐48 controlled by driver module ULN2003 - anhul/arduino GitHub Wiki

General

Controls unipolar stepper motor 28BYJ-48 using motor driver module ULN2003

The 28BYJ-48 is a 5-wire unipolar stepper motor that runs on 5V or 12V
The 28BYJ-48 has two coils, each of which has a center tap. These two center taps are connected internally and brought out as the 5th wire (red wire).
Together, one end of the coil and the center tap form a Phase. Thus, 28BYJ-48 has a total of four phases.
The stepper motor rotates only when the phases are energized in a logical sequence known as a step sequence.
when the 28BYJ-48 motor is operated in full-step mode, each step corresponds to a rotation of 11.25°. This means there are 32 steps per revolution (360°/11.25° = 32).
In addition, the gearbox inside the motor has a 64:1 gear reduction. This results in 2048 (32*64) steps per revolution.

Motor specification

The ULN2003 consists of an array of seven Darlington transistor pairs, each of which can drive a load of up to 500mA and 50V
There is an ON/OFF jumper on the board for disabling the stepper motor if needed.
IN1 – IN4 are motor control input pins. Connect them to the Arduino’s digital output pins.