Python Stepper Motor Controller

A lightweight Python class for controlling stepper motors using GPIO on a Raspberry Pi via the gpiozero library. Supports 2-pin, 4-pin, and 5-pin motors.

It essentially implements the same Stepper class logic as described in the Arduino Stepper library.

Features

• Compatible with 2-pin, 4-pin, and 5-pin stepper motors
• Forward and reverse movement
• Adjustable stepping delay (speed)
• Arduino-style stepping logic
• Easy integration with gpiozero
• Non-blocking and blocking modes
• Async mode and version

Requirements

• Raspberry Pi with GPIO
• Python 3.9+
• gpiozero library

Video Tutorial with Electronics

Installation

Place the stepper.py file containing the Stepper class in your project directory.
For asynchronous applications, place the async_stepper.py with AsyncStepper class file in your project directory.

Install dependencies if not already available. For example:

pip install gpiozero

or

sudo apt install python3-gpiozero

Usage

Standard methods

Initialize the object (example for 4-pin motor with 2048 steps):
step_motor = Stepper(2048, 5, 6, 13, 19)

Set the motor speed in rotations per minute (RPM):
step_motor.set_speed(8)

Move the motor one step forward:
step_motor.step(1)

Move the motor one step backward:
step_motor.step(-1)

Stop the motor immediately:
step_motor.stop()

Additional non-blocking methods:

Set the motor to move in a main loop:
step_motor.start(steps_to_move)

Call this in each iteration of the main loop:
step_motor.tick()

Async methods in async_stepper module:

Same as above, but class name is AsyncStepper, and without start() and tick() as they are not needed in async mode.

Examples

# 4-pin Stepper Motor on Raspberry Pi
from time import sleep
from stepper import Stepper

step_motor = Stepper(2048, 5, 6, 13, 19)
step_motor.set_speed(10)

try:
    while True:
        step_motor.step(1024)
        print("rotated half")
        sleep(2)
        step_motor.step(1024)
        print("rotated half more")
        sleep(2)
        step_motor.step(-1024)
        print("rotated half back")
        sleep(2)
        step_motor.step(-1024)
        print("rotated half more back")
        sleep(2)
except KeyboardInterrupt:
    pass
finally:
    step_motor.stop()

# Non-blocking mode example
from stepper import Stepper

motor = Stepper(2048, 5, 6, 13, 19)
motor.set_speed(10)
motor.start(1024) # can call in the main loop on event like sensor data

while True:
    t = motor.tick()
    # run other code while the motor works
    # or sleep(max(t, 0.0001))
    if motor.steps_left <= 0:
        break

# Acynchronous mode example
import asyncio
from async_stepper import AsyncStepper

async def run():
    motor = AsyncStepper(2048, 5, 6, 13, 19)
    motor.set_speed(8)
    await motor.step(2048)

asyncio.run(run())

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