Embedded Stepper Motor 28BYJ-48

Introduction

With this project we will manage a Stepper Motor 28BYJ-48, using the FTDI FT232H development board (of which there is a dedicated page on this site). The Stepper Motor must be connected to a control board based on STMicroelectronics ULN2003 chipset.

Connection

This Stepper Motor must be connected to the ULN2003 board, while the latter must be connected to the FTDI FT232H development board. The connection connectors are listed below:

Python code

To manage this Stepper Motor, the presence of the "PyFTDI" library is required.
The following Python code example firstly runs the Stepper Motor fast, then slowly:

from os import environ
from pyftdi.gpio import GpioAsyncController
import time

clockwise = [[0b1000], [0b0100], [0b0010], [0b0001]]

def MotorCW(time_s, speed):
    counts = int(time_s /speed/16)
    for i in range(counts):
        for i in range(4):
            _gpio.write(clockwise[i])
            time.sleep(speed)
    _gpio.write(0)

def MotorCCW(time_s, speed):
    counts = int(time_s /speed/16)
    for i in range(counts):
        for i in reversed(range(4)):
            _gpio.write(clockwise[i])
            time.sleep(speed)
    _gpio.write(0)

_ctrl = GpioAsyncController()
url = environ.get('FTDI_DEVICE', 'ftdi:///1')
_ctrl.configure(url, direction=0b0, frequency=None, initial=0b0)
_gpio = _ctrl.get_gpio()
_gpio.set_direction(0b1111, 0b1111)

try:
    print("\nFast Clockwise...")
    MotorCW(20, 0.0020)
    time.sleep(0.5)
    print("\nFast Counterclockwise...")
    MotorCCW(20, 0.0020)
    time.sleep(0.5)
    print("\nSlow Clockwise...")
    MotorCW(20, 0.010)
    time.sleep(0.5)
    print("\nSlow Counterclockwise...")
    MotorCCW(20, 0.010)

except KeyboardInterrupt:
    # Capture keyboard ^C to exit the program
    print('\nYou terminated the program. The program ends!')
    _gpio.write(0)