stepper.py

# -*- coding: utf-8 -*-
import RPi.GPIO as GPIO
import time
import click


class Stepper():
    """
    """

    DIR_OPEN = GPIO.LOW
    DIR_CLOSE = GPIO.HIGH

    ENABLED = GPIO.HIGH
    DISABLED = GPIO.LOW

    def __init__(self, enable_pin, direction_pin, pulse_pin):
        """
        """
        self.pulse_width = 300  # pulse width in microseconds
        self.pulse_delay = self.pulse_width + 200  # delay between pulses in microseconds

        self.enable_pin = enable_pin
        self.direction_pin = direction_pin
        self.pulse_pin = pulse_pin

        GPIO.setmode(GPIO.BOARD)
        
        GPIO.setup(enable_pin, GPIO.OUT, initial=Stepper.DISABLED)
        GPIO.setup(direction_pin, GPIO.OUT, initial=Stepper.DIR_OPEN)
        GPIO.setup(pulse_pin, GPIO.OUT, initial=GPIO.LOW)

    def cleanup(self):
        GPIO.cleanup()

    # def set_speed(self, rpms):
    #     """
    #     Sets the speed in revs per minute. The delay between each step in microseconds based on RPMs
    #     """
    #     self.step_delay = 60L * 1000L * 1000L / self.number_of_steps / rpms;

    def set_direction(self, direction):
        GPIO.output(self.direction_pin, direction)

    def step(self, steps):
        GPIO.output(self.enable_pin, Stepper.ENABLED)
        steps_left = steps
        last_step_time = 0
        while steps_left > 0:
            now = long(time.time() * 1000000)
            if (now - last_step_time) >= self.pulse_delay:
                last_step_time = now
                steps_left -= 1
                self.step_motor()
        GPIO.output(self.enable_pin, Stepper.DISABLED)

    def step_motor(self):
        GPIO.output(self.pulse_pin, GPIO.HIGH)
        pulse_start = long(time.time() * 1000000)
        now = pulse_start
        while True:
            now = long(time.time() * 1000000)
            if (now - pulse_start) >= self.pulse_width:
                GPIO.output(self.pulse_pin, GPIO.LOW)
                break

@click.command()
@click.option('--rotations', default=1, help='Number of full rotations to make')
def main(rotations):
    click.echo('%s rotations' % (rotations))

    stepper = Stepper(11, 13, 15)

    if rotations < 0:
        stepper.set_direction(Stepper.DIR_OPEN)
    else:
        stepper.set_direction(Stepper.DIR_CLOSE)
        
    start_time = time.time()
    
    stepper.step(200 * abs(rotations))

    end_time = time.time()
    duration = end_time - start_time
    click.echo('Duration %s seconds' % duration)

    stepper.cleanup()


if __name__ == "__main__":
    main()