kopia lustrzana https://github.com/pimoroni/pimoroni-pico
121 wiersze
4.2 KiB
Python
121 wiersze
4.2 KiB
Python
import time
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from pimoroni import PID, NORMAL_DIR # , REVERSED_DIR
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from inventor import Inventor2040W, MOTOR_A, NUM_LEDS
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"""
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A demonstration of how a motor with an encoder can be used
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as a programmable rotary encoder for user input, with
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force-feedback for arbitrary detents and end stops.
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Press "User" to exit the program.
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"""
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GEAR_RATIO = 50 # The gear ratio of the motor
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DIRECTION = NORMAL_DIR # The direction to spin the motor in. NORMAL_DIR (0), REVERSED_DIR (1)
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SPEED_SCALE = 5.4 # The scaling to apply to the 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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PRINT_DIVIDER = 4 # How many of the updates should be printed (i.e. 2 would be every other update)
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# Multipliers for the different printed values, so they appear nicely on the Thonny plotter
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SPD_PRINT_SCALE = 20 # Driving Speed multipler
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DETENT_SIZE = 20 # The size (in degrees) of each detent region
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MIN_DETENT = 0 # The minimum detent that can be counted to
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MAX_DETENT = NUM_LEDS - 1 # The maximum detent that can be counted to
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MAX_DRIVE_PERCENT = 0.5 # The maximum drive force (as a percent) to apply when crossing detents
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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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# Create a new Inventor2040W and get a motor and encoder from it
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board = Inventor2040W(motor_gear_ratio=GEAR_RATIO)
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m = board.motors[MOTOR_A]
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enc = board.encoders[MOTOR_A]
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# Set the motor's speed scale
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m.speed_scale(SPEED_SCALE)
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# Set the motor and encoder's direction
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m.direction(DIRECTION)
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enc.direction(DIRECTION)
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# Create PID object for position control
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pos_pid = PID(POS_KP, POS_KI, POS_KD, UPDATE_RATE)
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# Enable the motor to get started
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m.enable()
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current_detent = 0
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# Function to deal with a detent change
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def detent_change(change):
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global current_detent
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# Update the current detent and pid setpoint
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current_detent += change
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pos_pid.setpoint = (current_detent * DETENT_SIZE) # Update the motor position setpoint
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print("Detent =", current_detent)
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# Convert the current detent to a hue and set the onboard led to it
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hue = (current_detent - MIN_DETENT) / (MAX_DETENT - MIN_DETENT)
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for i in range(NUM_LEDS):
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if current_detent == i:
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board.leds.set_hsv(i, hue, 1.0, BRIGHTNESS)
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else:
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board.leds.set_hsv(i, hue, 1.0, 0.0)
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# Call the function once to set the setpoint and print the value
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detent_change(0)
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# Continually move the motor until the user button is pressed
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while not board.switch_pressed():
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# Capture the state of the encoder
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capture = enc.capture()
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# Get the current detent's centre angle
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detent_angle = (current_detent * DETENT_SIZE)
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# Is the current angle above the region of this detent?
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if capture.degrees > detent_angle + (DETENT_SIZE / 2):
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# Is there another detent we can move to?
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if current_detent < MAX_DETENT:
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detent_change(1) # Increment to the next detent
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# Is the current angle below the region of this detent?
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elif capture.degrees < detent_angle - (DETENT_SIZE / 2):
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# Is there another detent we can move to?
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if current_detent > MIN_DETENT:
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detent_change(-1) # Decrement to the next detent
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# Calculate the velocity to move the motor closer to the position setpoint
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vel = pos_pid.calculate(capture.degrees, capture.degrees_per_second)
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# If the current angle is within the detent range, limit the max vel
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# (aka feedback force) that the user will feel when turning the motor between detents
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if (capture.degrees >= MIN_DETENT * DETENT_SIZE) and (capture.degrees <= MAX_DETENT * DETENT_SIZE):
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vel = max(min(vel, MAX_DRIVE_PERCENT), -MAX_DRIVE_PERCENT)
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# Set the new motor driving speed
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m.speed(vel)
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time.sleep(UPDATE_RATE)
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# Disable the motor
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m.disable()
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# Turn off the LEDs
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board.leds.clear()
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