Natuurlijk wilde ik ook een motortje aan de Pico hangen. Een stappenmotortje; de hier al veel vaker gebruikte 28BYJ-48 dus.
Net als voor het OLED-scherm aansturing ik ook voor deze stappenmotor niet een “pakket” voor MicroPython beschikbaar. Maar het duo Rui & Sara Santos heeft op hun site wel iets beschikbaar.
# Rui Santos & Sara Santos - Random Nerd Tutorials
# Complete project details at https://RandomNerdTutorials.com/raspberry-pi-pico-stepper-motor-micropython/
# Forked from: https://github.com/larsks/micropython-stepper-motor/blob/master/motor.py
import machine
import time
class Motor:
stepms = 10
# Do be defined by subclasses
maxpos = 0
states = []
def __init__(self, p1, p2, p3, p4, stepms=None):
self.pins = [p1, p2, p3, p4]
if stepms is not None:
self.stepms = stepms
self._state = 0
self._pos = 0
def __repr__(self):
return '<{} @ {}>'.format(
self.__class__.__name__,
self.pos,
)
@property
def pos(self):
return self._pos
@classmethod
def frompins(cls, *pins, **kwargs):
return cls(*[machine.Pin(pin, machine.Pin.OUT) for pin in pins],
**kwargs)
def reset(self):
self._pos = 0
def _step(self, dir):
state = self.states[self._state]
for i, val in enumerate(state):
self.pins[i].value(val)
self._state = (self._state + dir) % len(self.states)
self._pos = (self._pos + dir) % self.maxpos
def step(self, steps):
dir = 1 if steps >= 0 else -1
steps = abs(steps)
for _ in range(steps):
t_start = time.ticks_ms()
self._step(dir)
t_end = time.ticks_ms()
t_delta = time.ticks_diff(t_end, t_start)
time.sleep_ms(self.stepms - t_delta)
def step_until(self, target, dir=None):
if target < 0 or target > self.maxpos:
raise ValueError(target)
if dir is None:
dir = 1 if target > self._pos else -1
if abs(target - self._pos) > self.maxpos/2:
dir = -dir
while True:
if self._pos == target:
break
self.step(dir)
def step_until_angle(self, angle, dir=None):
if angle < 0 or angle > 360:
raise ValueError(angle)
target = int(angle / 360 * self.maxpos)
self.step_until(target, dir=dir)
def step_degrees(self, degrees):
if degrees < 0 or degrees > 360:
raise ValueError("Degrees should be between 0 and 360")
steps_to_take = int(degrees / 360 * self.maxpos)
self.zero() # Ignore the current position, start from zero
self.step(steps_to_take)
class FullStepMotor(Motor):
stepms = 5
maxpos = 2048
states = [
[1, 1, 0, 0],
[0, 1, 1, 0],
[0, 0, 1, 1],
[1, 0, 0, 1],
]
class HalfStepMotor(Motor):
stepms = 3
maxpos = 4096
states = [
[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],
]
Bovenstaande script als “Stepper.py” naar de Pico gestuurd en onderstaand script uitgevoerd doet de motor prima heen er weer gaan.
# Rui Santos & Sara Santos - Random Nerd Tutorials
# Complete project details at https://RandomNerdTutorials.com/raspberry-pi-pico-stepper-motor-micropython/
import stepper
from time import sleep
# Define the stepper motor pins
IN1 = 28
IN2 = 27
IN3 = 26
IN4 = 22
# Initialize the stepper motor
stepper_motor = stepper.HalfStepMotor.frompins(IN1, IN2, IN3, IN4)
# Set the current position as position 0
stepper_motor.reset()
try:
while True:
#Move 500 steps in clockwise direction
stepper_motor.step(500)
sleep(0.5) # stop for a while
# Move 500 steps in counterclockwise direction
stepper_motor.step(-500)
sleep(0.5) # stop for a while
# Go to a specific position (in steps)
stepper_motor.step_until(2000)
sleep(0.5) # stop for a while
# Force a direction using the dir paramter
stepper_motor.step_until(2000, dir=-1)
sleep(0.5) # stop for a while
# Go to a specific position (angle, maximum is 359, otherwise it will spin indefinetely)
stepper_motor.step_until_angle(90)
sleep(0.5) # stop for a while
stepper_motor.step_until_angle(45)
sleep(0.5) # stop for a while
stepper_motor.step_until_angle(135)
sleep(0.5) # stop for a while
stepper_motor.step_until_angle(180)
sleep(0.5) # stop for a while
except KeyboardInterrupt:
print('Keyboard interrupt')
Stepper_heen_en_weer.py
# Rui Santos & Sara Santos - Random Nerd Tutorials
# Complete project details at https://RandomNerdTutorials.com/raspberry-pi-pico-stepper-motor-micropython/
import stepper
from time import sleep
# Define the stepper motor 1 pins
IN1 = 28
IN2 = 27
IN3 = 26
IN4 = 22
# Define the stepper motor 2 pins
IN5 = 10
IN6 = 11
IN7 = 12
IN8 = 13
# Initialize the stepper motor
stepper_motor_1 = stepper.HalfStepMotor.frompins(IN1, IN2, IN3, IN4)
stepper_motor_2 = stepper.HalfStepMotor.frompins(IN5, IN6, IN7, IN8)
# Set the current position as position 0
stepper_motor_1.reset()
stepper_motor_2.reset()
try:
while True:
#Move 500 steps in clockwise direction
stepper_motor_1.step(500)
stepper_motor_2.step(500)
sleep(0.5) # stop for a while
# Move 500 steps in counterclockwise direction
stepper_motor_1.step(-500)
sleep(0.5) # stop for a while
# Go to a specific position (in steps)
stepper_motor_2.step_until(2000)
sleep(0.5) # stop for a while
# Force a direction using the dir paramter
stepper_motor_2.step_until(2000, dir=-1)
sleep(0.5) # stop for a while
# Go to a specific position (angle, maximum is 359, otherwise it will spin indefinetely)
stepper_motor_1.step_until_angle(90)
sleep(0.5) # stop for a while
stepper_motor_1.step_until_angle(45)
sleep(0.5) # stop for a while
stepper_motor_2.step_until_angle(135)
sleep(0.5) # stop for a while
stepper_motor_2.step_until_angle(180)
sleep(0.5) # stop for a while
except KeyboardInterrupt:
print('Keyboard interrupt')
Een tweede motor eraan is eenvoudig. De eerste motor zit op de pinnen: IN1 = GPIO28, IN2 = GPIO27, IN3 = GPIO26 en IN4 = GPIO22. De tweede motor: IN5 = GPIO10, IN6 = GPIO11, IN7 = GPIO12 en IN8 = GPIO13.