kopia lustrzana https://github.com/pimoroni/pimoroni-pico
131 wiersze
4.2 KiB
Python
131 wiersze
4.2 KiB
Python
import gc
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import time
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import math
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from plasma import WS2812
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from motor import Motor, motor2040
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from encoder import Encoder, MMME_CPR
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from pimoroni import Button, PID, REVERSED_DIR
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"""
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A demonstration of driving all four of Motor 2040's motor outputs between
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positions, with the help of their attached encoders and PID control.
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Press "Boot" to exit the program.
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"""
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GEAR_RATIO = 50 # The gear ratio of the motors
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COUNTS_PER_REV = MMME_CPR * GEAR_RATIO # The counts per revolution of each motor's output shaft
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SPEED_SCALE = 5.4 # The scaling to apply to each motor's speed to match its real-world speed
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UPDATES = 100 # How many times to update the motor per second
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UPDATE_RATE = 1 / UPDATES
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TIME_FOR_EACH_MOVE = 2 # The time to travel between each value
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UPDATES_PER_MOVE = TIME_FOR_EACH_MOVE * UPDATES
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PRINT_DIVIDER = 4 # How many of the updates should be printed (i.e. 2 would be every other update)
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# LED constant
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BRIGHTNESS = 0.4 # The brightness of the RGB LED
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# PID values
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POS_KP = 0.14 # Position proportional (P) gain
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POS_KI = 0.0 # Position integral (I) gain
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POS_KD = 0.0022 # Position derivative (D) gain
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# Free up hardware resources ahead of creating a new Encoder
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gc.collect()
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# Create a list of motors with a given speed scale
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MOTOR_PINS = [motor2040.MOTOR_A, motor2040.MOTOR_B, motor2040.MOTOR_C, motor2040.MOTOR_D]
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motors = [Motor(pins, speed_scale=SPEED_SCALE) for pins in MOTOR_PINS]
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# Create a list of encoders, using PIO 0, with the given counts per revolution
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ENCODER_PINS = [motor2040.ENCODER_A, motor2040.ENCODER_B, motor2040.ENCODER_C, motor2040.ENCODER_D]
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ENCODER_NAMES = ["A", "B", "C", "D"]
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encoders = [Encoder(0, i, ENCODER_PINS[i], counts_per_rev=COUNTS_PER_REV, count_microsteps=True) for i in range(motor2040.NUM_MOTORS)]
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# Reverse the direction of the B and D motors and encoders
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motors[1].direction(REVERSED_DIR)
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motors[3].direction(REVERSED_DIR)
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encoders[1].direction(REVERSED_DIR)
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encoders[3].direction(REVERSED_DIR)
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# Create the LED, using PIO 1 and State Machine 0
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led = WS2812(motor2040.NUM_LEDS, 1, 0, motor2040.LED_DATA)
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# Create the user button
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user_sw = Button(motor2040.USER_SW)
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# Create PID objects for position control
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pos_pids = [PID(POS_KP, POS_KI, POS_KD, UPDATE_RATE) for i in range(motor2040.NUM_MOTORS)]
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# Start updating the LED
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led.start()
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# Enable all motors
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for m in motors:
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m.enable()
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update = 0
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print_count = 0
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# Set the initial and end values
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start_value = 0.0
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end_value = 270.0
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captures = [None] * motor2040.NUM_MOTORS
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# Continually move the motor until the user button is pressed
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while user_sw.raw() is not True:
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# Capture the state of all the encoders
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for i in range(motor2040.NUM_MOTORS):
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captures[i] = encoders[i].capture()
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# Calculate how far along this movement to be
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percent_along = min(update / UPDATES_PER_MOVE, 1.0)
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for i in range(motor2040.NUM_MOTORS):
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# Move the motor between values using cosine
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pos_pids[i].setpoint = (((-math.cos(percent_along * math.pi) + 1.0) / 2.0) * (end_value - start_value)) + start_value
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# Calculate the velocity to move the motor closer to the position setpoint
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vel = pos_pids[i].calculate(captures[i].degrees, captures[i].degrees_per_second)
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# Set the new motor driving speed
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motors[i].speed(vel)
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# Update the LED
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led.set_hsv(0, percent_along, 1.0, BRIGHTNESS)
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# Print out the current motor values and their setpoints, but only on every multiple
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if print_count == 0:
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for i in range(motor2040.NUM_MOTORS):
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print(ENCODER_NAMES[i], "=", captures[i].degrees, end=", ")
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print()
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# Increment the print count, and wrap it
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print_count = (print_count + 1) % PRINT_DIVIDER
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update += 1 # Move along in time
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# Have we reached the end of this movement?
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if update >= UPDATES_PER_MOVE:
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update = 0 # Reset the counter
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# Swap the start and end values
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temp = start_value
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start_value = end_value
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end_value = temp
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time.sleep(UPDATE_RATE)
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# Stop all the motors
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for m in motors:
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m.disable()
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# Turn off the LED bar
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led.clear()
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