Circuit Documentation

Summary

This circuit is designed to control a 28BYJ-48 Stepper Motor using an Arduino 101 microcontroller and a ULN2003A breakout board. The Arduino 101 sends control signals to the ULN2003A, which in turn drives the stepper motor. The circuit is powered by a 5V supply, and the ground connections are shared between the Arduino and the ULN2003A board.

Component List

ULN2003A Breakout Board

• Description: A breakout board for the ULN2003A, a 7-channel Darlington array designed for driving high-current loads.
• Pins: In 1, In 2, In 3, In 4, In 5, In 6, In 7, 0V, +5V, ON/OFF jumper switch, BLUE wire, PINK wire, YELLOW wire, ORANGE wire, RED wire.

Arduino 101

• Description: A microcontroller board based on the Intel Curie, which is capable of Bluetooth Low Energy communications and sensor integration.
• Pins: A5/SCL, A4/SDA, AREF, GND, D13/SCK, D12/MISO, D11 PWM/MOSI, D10 PWM/SS, D9 PWM, D8, D7, D6 PWM, D5 PWM, D4, D3 PWM, D2, D1/TX, D0/RX, AIN, ioref, RESET, 3V3, 5V, VIN, A0, A1, A2, A3, ICSP MISO, ICSP SCK, ICSP MOSI.

28BYJ-48 Stepper Motor

• Description: A small, 5-wire, unipolar stepper motor commonly used for precision control in projects.
• Pins: BLUE, PINK, YELLOW, ORANGE, RED.

Wiring Details

ULN2003A Breakout Board

• In 1: Connected to Arduino 101 D8
• In 2: Connected to Arduino 101 D9 PWM
• In 3: Connected to Arduino 101 D10 PWM/SS
• In 4: Connected to Arduino 101 D11 PWM/MOSI
• 0V: Connected to Arduino 101 GND
• +5V: Connected to Arduino 101 5V
• BLUE wire: Connected to 28BYJ-48 Stepper Motor BLUE
• PINK wire: Connected to 28BYJ-48 Stepper Motor PINK
• YELLOW wire: Connected to 28BYJ-48 Stepper Motor YELLOW
• ORANGE wire: Connected to 28BYJ-48 Stepper Motor ORANGE
• RED wire: Connected to 28BYJ-48 Stepper Motor RED

Arduino 101

• D8: Connected to ULN2003A In 1
• D9 PWM: Connected to ULN2003A In 2
• D10 PWM/SS: Connected to ULN2003A In 3
• D11 PWM/MOSI: Connected to ULN2003A In 4
• GND: Connected to ULN2003A 0V
• 5V: Connected to ULN2003A +5V

28BYJ-48 Stepper Motor

• BLUE: Connected to ULN2003A BLUE wire
• PINK: Connected to ULN2003A PINK wire
• YELLOW: Connected to ULN2003A YELLOW wire
• ORANGE: Connected to ULN2003A ORANGE wire
• RED: Connected to ULN2003A RED wire

Documented Code

#include <Stepper.h>

#define STEPS 32

Stepper stepper(STEPS, 8, 9, 10, 11);

int val = 0;

void setup() {
  Serial.begin(9600);
  stepper.setSpeed(200);
}

void loop() {
  if (Serial.available() > 0) {
    val = Serial.parseInt();
    stepper.step(val);
    Serial.println(val);
  }
}

Filename: sketch.ino

Code Description

• The code includes the Stepper.h library, which is used to control stepper motors with the Arduino.
• STEPS is defined as 32, which is the number of steps per revolution for the 28BYJ-48 stepper motor.
• An instance of the Stepper class is created named stepper, initialized with the number of steps and the pins connected to the ULN2003A inputs.
• In the setup() function, the serial communication is started at 9600 baud, and the stepper motor speed is set to 200 RPM.
• The loop() function continuously checks for available serial input. If a value is received, it is parsed as an integer, the stepper motor is moved by that number of steps, and the value is printed back to the serial monitor.