import gc import time from pimoroni import Button, PID from plasma import WS2812 from motor import Motor, motor2040 from encoder import Encoder, MMME_CPR """ A demonstration of how a motor with an encoder can be used as a programmable rotary encoder for user input, with force-feedback for arbitrary detents and end stops. Press "Boot" to exit the program. NOTE: Plasma WS2812 uses the RP2040's PIO system, and as such may have problems when running code multiple times. If you encounter issues, try resetting your board. """ MOTOR_PINS = motor2040.MOTOR_A # The pins of the motor being profiled ENCODER_PINS = motor2040.ENCODER_A # The pins of the encoder attached to the profiled motor GEAR_RATIO = 50 # The gear ratio of the motor COUNTS_PER_REV = MMME_CPR * GEAR_RATIO # The counts per revolution of the motor's output shaft DIRECTION = 0 # The direction to spin the motor in. NORMAL (0), REVERSED (1) SPEED_SCALE = 5.4 # The scaling to apply to the motor's speed to match its real-world speed UPDATES = 100 # How many times to update the motor per second UPDATE_RATE = 1 / UPDATES PRINT_DIVIDER = 4 # How many of the updates should be printed (i.e. 2 would be every other update) # Multipliers for the different printed values, so they appear nicely on the Thonny plotter SPD_PRINT_SCALE = 20 # Driving Speed multipler DETENT_SIZE = 20 # The size (in degrees) of each detent region MIN_DETENT = -12 # The minimum detent that can be counted to MAX_DETENT = +12 # The maximum detent that can be counted to MAX_DRIVE_PERCENT = 0.5 # The maximum drive force (as a percent) to apply when crossing detents # PID values POS_KP = 0.14 # Position proportional (P) gain POS_KI = 0.0 # Position integral (I) gain POS_KD = 0.0022 # Position derivative (D) gain BRIGHTNESS = 0.4 # The brightness of the LEDs # Free up hardware resources ahead of creating a new Encoder gc.collect() # Create a motor and set its speed scale m = Motor(MOTOR_PINS, direction=DIRECTION, speed_scale=SPEED_SCALE, deadzone=0.05) # Create an encoder, using PIO 0 and State Machine 0 enc = Encoder(0, 0, ENCODER_PINS, direction=DIRECTION, counts_per_rev=COUNTS_PER_REV, count_microsteps=True) # Create the LED, using PIO 0 and State Machine 1 led = WS2812(motor2040.NUM_LEDS, 0, 1, motor2040.LED_DATA) # Create the user button user_sw = Button(motor2040.USER_SW) # Create PID object for position control pos_pid = PID(POS_KP, POS_KI, POS_KD, UPDATE_RATE) # Start updating the LED led.start() # Enable the motor to get started m.enable() current_detent = 0 # Function to deal with a detent change def detent_change(change): global current_detent # Update the current detent and pid setpoint current_detent += change pos_pid.setpoint = (current_detent * DETENT_SIZE) # Update the motor position setpoint print("Detent =", current_detent) # Convert the current detent to a hue and set the onboard led to it hue = (current_detent - MIN_DETENT) / (MAX_DETENT - MIN_DETENT) led.set_hsv(0, hue, 1.0, BRIGHTNESS) # Call the function once to set the setpoint and print the value detent_change(0) # Continually move the motor until the user button is pressed while user_sw.raw() is not True: # Capture the state of the encoder capture = enc.capture() # Get the current detent's centre angle detent_angle = (current_detent * DETENT_SIZE) # Is the current angle above the region of this detent? if capture.degrees > detent_angle + (DETENT_SIZE / 2): # Is there another detent we can move to? if current_detent < MAX_DETENT: detent_change(1) # Increment to the next detent # Is the current angle below the region of this detent? elif capture.degrees < detent_angle - (DETENT_SIZE / 2): # Is there another detent we can move to? if current_detent > MIN_DETENT: detent_change(-1) # Decrement to the next detent # Calculate the velocity to move the motor closer to the position setpoint vel = pos_pid.calculate(capture.degrees, capture.degrees_per_second) # If the current angle is within the detent range, limit the max vel # (aka feedback force) that the user will feel when turning the motor between detents if (capture.degrees >= MIN_DETENT * DETENT_SIZE) and (capture.degrees <= MAX_DETENT * DETENT_SIZE): vel = max(min(vel, MAX_DRIVE_PERCENT), -MAX_DRIVE_PERCENT) # Set the new motor driving speed m.speed(vel) time.sleep(UPDATE_RATE) # Disable the motor m.disable() # Turn off the LED led.clear()