Documentation

// 28BYJ-48 + ULN2003 - Arduino full revolution example
// IN1->D8, IN2->D9, IN3->D10, IN4->D11
// NOTE: Stepper.h pin order is (IN1, IN3, IN2, IN4) — not 1,2,3,4!

#include 

// Steps per revolution for the 28BYJ-48 (full step with 64:1 gearbox)
const int STEPS_PER_REV = 2048;

// Stepper(steps, pin1, pin3, pin2, pin4) — note the swapped order
Stepper motor(STEPS_PER_REV, 8, 10, 9, 11);

void setup() {
  Serial.begin(9600);
  motor.setSpeed(10);  // RPM (max ~15 RPM for 28BYJ-48)
}

void loop() {
  Serial.println("One revolution clockwise");
  motor.step(STEPS_PER_REV);
  delay(1000);

  Serial.println("One revolution counter-clockwise");
  motor.step(-STEPS_PER_REV);
  delay(1000);
}

#!/usr/bin/env python3
# 28BYJ-48 + ULN2003 - Raspberry Pi half-step example
# IN1->GPIO 17, IN2->GPIO 27, IN3->GPIO 22, IN4->GPIO 23

import RPi.GPIO as GPIO
import time

PINS = [17, 27, 22, 23]  # IN1, IN2, IN3, IN4

# 8-step half-stepping sequence for smoother motion
HALF_STEP = [
    [1, 0, 0, 0],
    [1, 1, 0, 0],
    [0, 1, 0, 0],
    [0, 1, 1, 0],
    [0, 0, 1, 0],
    [0, 0, 1, 1],
    [0, 0, 0, 1],
    [1, 0, 0, 1],
]

GPIO.setmode(GPIO.BCM)
for pin in PINS:
    GPIO.setup(pin, GPIO.OUT)
    GPIO.output(pin, 0)

def step(direction=1, steps=4096, delay_s=0.001):
    seq = HALF_STEP if direction > 0 else list(reversed(HALF_STEP))
    for i in range(steps):
        for pin, val in zip(PINS, seq[i % 8]):
            GPIO.output(pin, val)
        time.sleep(delay_s)

try:
    print("Rotating one full revolution clockwise...")
    step(direction=1, steps=4096)  # 4096 = one revolution in half-step mode
    time.sleep(1)
    print("Rotating one full revolution counter-clockwise...")
    step(direction=-1, steps=4096)
finally:
    for pin in PINS:
        GPIO.output(pin, 0)
    GPIO.cleanup()

# 28BYJ-48 + ULN2003 - Pico MicroPython half-step example
# IN1->GP2, IN2->GP3, IN3->GP4, IN4->GP5

from machine import Pin
import time

pins = [Pin(2, Pin.OUT), Pin(3, Pin.OUT), Pin(4, Pin.OUT), Pin(5, Pin.OUT)]

HALF_STEP = [
    (1, 0, 0, 0),
    (1, 1, 0, 0),
    (0, 1, 0, 0),
    (0, 1, 1, 0),
    (0, 0, 1, 0),
    (0, 0, 1, 1),
    (0, 0, 0, 1),
    (1, 0, 0, 1),
]

def step(direction=1, steps=4096, delay_ms=2):
    seq = HALF_STEP if direction > 0 else tuple(reversed(HALF_STEP))
    for i in range(steps):
        pattern = seq[i % 8]
        for pin, val in zip(pins, pattern):
            pin.value(val)
        time.sleep_ms(delay_ms)

try:
    print("One full revolution clockwise")
    step(direction=1, steps=4096)
    time.sleep(1)
    print("One full revolution counter-clockwise")
    step(direction=-1, steps=4096)
finally:
    for p in pins:
        p.value(0)

# 28BYJ-48 + ULN2003 - ESP32 MicroPython example
# IN1->GPIO 14, IN2->GPIO 27, IN3->GPIO 26, IN4->GPIO 25

from machine import Pin
import time

pins = [Pin(14, Pin.OUT), Pin(27, Pin.OUT), Pin(26, Pin.OUT), Pin(25, Pin.OUT)]

# Full-step sequence (faster, slightly less smooth than half-step)
FULL_STEP = [
    (1, 1, 0, 0),
    (0, 1, 1, 0),
    (0, 0, 1, 1),
    (1, 0, 0, 1),
]

def step(direction=1, steps=2048, delay_ms=3):
    seq = FULL_STEP if direction > 0 else tuple(reversed(FULL_STEP))
    for i in range(steps):
        pattern = seq[i % 4]
        for pin, val in zip(pins, pattern):
            pin.value(val)
        time.sleep_ms(delay_ms)

try:
    while True:
        print("CW one revolution")
        step(direction=1, steps=2048)  # 2048 = one revolution in full-step mode
        time.sleep(1)
        print("CCW one revolution")
        step(direction=-1, steps=2048)
        time.sleep(1)
except KeyboardInterrupt:
    for p in pins:
        p.value(0)