Simple 4 Phase UNL 2003 Stepper Motor Driver PCB controller script for Raspberry PI

motor.py

#!/usr/bin/env python
## Written by Aki Tuomi 2022
# Released into public domain with NO WARRANTY
# Written for 4 Phase UNL 2003 Stepper Motor Driver PCB

##

# To use, update INx to match your setup
# Then choose steps_4 or steps_8 as steps (4 or 8 steps)
# You can use UP and DOWN arrow to adjust speed
# LEFT and RIGHT arrow to change direction
# q to quit

from RPi import GPIO
import time
import random
from time import sleep
import curses

# Where the stepper has been connected
# Please see RPi.GPIO documentation
IN1 = 31
IN2 = 33
IN3 = 35
IN4 = 37

# channels and steps. These must match
channels = [IN1, IN2, IN3, IN4]

# If you want 8 steps, update this array
# to match the steps you want.
steps_4 = [
  [1, 1, 0, 0], # AB
  [0, 1, 1, 0], # BC
  [0, 0, 1, 1], # CD
  [1, 0, 0, 1], # DA
]

steps_8 = [
  [1, 0, 0, 0], # A
  [1, 1, 0, 0], # AB
  [0, 1, 0, 0], # B
  [0, 1, 1, 0], # BC
  [0, 0, 1, 0], # C
  [0, 0, 1, 1], # CD
  [0, 0, 0, 1], # D
  [1, 0, 0, 1], # DA
]

steps = steps_8

# Gives us 8 different speeds.
# 0.002 seems to be shortest period that works
# faster than that causes the motor to not move.
speeds = [0.1, 0.07, 0.05, 0.02, 0.01, 0.007, 0.005, 0.002]

# Initialize GPIO
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BOARD)

# Setup & clear channels
GPIO.setup(channels, GPIO.OUT)
GPIO.output(channels, 0)


def do_step(state):
    """Perform single step by setting the channels
       to the current step's coding"""
    step = steps[state.get("step",0)]
    GPIO.output(channels, step)
    # Wait a bit
    sleep(speeds[state["speed"]])

def go_faster(state):
    """Go faster (moves to faster speed, wraps around)"""
    state["speed"] = (state["speed"] + 1) % len(speeds)


def go_slower(state):
    """Go slower, (moves tos lower speed, wraps around)"""
    state["speed"] = (state["speed"] - 1) % len(speeds)


def go_cw(state):
    """Go clockwise"""
    state["direction"] = "CW"


def go_ccw(state):
    """Go counter-clockwise"""
    state["direction"] = "CCW"


def update_step(state):
    """Update next stepper step"""
    step = state.get("step", 0)
    if state["direction"] == "CW":
        step = (step + 1) % len(steps)
    elif state["direction"] == "CCW":
        step = (step - 1) % len(steps)
    state["step"] = step


def main(stdscr):
    stdscr.nodelay(1)
    try:
        # Start going slowly clockwise
        state = {
         "speed": 0,
         "direction": "CW"
        }
        while True:
            c = stdscr.getch()
            if c != -1:
                if c == curses.KEY_UP:
                    go_faster(state)
                elif c == curses.KEY_DOWN:
                    go_slower(state)
                elif c == curses.KEY_LEFT:
                    go_ccw(state)
                elif c == curses.KEY_RIGHT:
                    go_cw(state)
                elif c == ord("q"):
                    break
                print(f"Going {state['direction']} at {state['speed']}\r")
            do_step(state)
            update_step(state)
    except KeyboardInterrupt:
        # catch CTRL+C
        pass
    finally:
        # Clear channels when we are leaving
        GPIO.output(channels, 0)

if __name__ == "__main__":
    curses.wrapper(main)