Powered Up Remote Control

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Control the Cat Bulldozer with the Powered Up Remote!

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Program

This program lets you drive and operate the Cat® D11 Bulldozer using the Powered Up remote control. No smartphone required!

When the program begins, it resets the function selector to the zero position, corresponding to the blade up and down movement. You can select any function by pressing the green button along with one of the gray buttons. This will change the remote light and switch the function selector as follows:

• Left ＋ (blue): Moves the blade up and down.
• Left − (red): Tilts the blade back and forth.
• Right ＋ (yellow): Moves the ladder up and down.
• Right − (green): Moves the ripper up and down.

Once the function is selected, use the red buttons to control the motor that powers the selected function.

Use the gray buttons to control the tracks. You can change the DRIVE_ACCELERATION value in the code to a lower value to make the vehicle start and stop driving more gradually. You can also change the speed by reducing the DRIVE_SPEED value.

from pybricks.pupdevices import Motor, Remote
from pybricks.parameters import Button, Color, Direction, Port
from pybricks.tools import wait, StopWatch

# Connect to the remote.
remote = Remote()

# Default speed and acceleration. You can change
# them to make it more realistic.
SWITCH_SPEED = 720
DRIVE_SPEED = 1000
DRIVE_ACCELERATION = 2500
FUNCTION_POWER = 100

# Initialize the motors.
left_motor = Motor(Port.A, Direction.COUNTERCLOCKWISE)
right_motor = Motor(Port.B)
function_motor = Motor(Port.C)
switch_motor = Motor(Port.D)

left_motor.control.limits(acceleration=DRIVE_ACCELERATION)
right_motor.control.limits(acceleration=DRIVE_ACCELERATION)

# Buttons paired with the green button to make a command.
COMMANDS = {
    Button.LEFT_PLUS: ("Blade up/down", 0, Color.BLUE),
    Button.LEFT_MINUS: ("Blade tilt", 270, Color.RED),
    Button.RIGHT_PLUS: ("Ladder", 180, Color.YELLOW),
    Button.RIGHT_MINUS: ("Ripper", 90, Color.GREEN),
}

# Find the right end left endstop positions
right_end = switch_motor.run_until_stalled(500, duty_limit=50)
left_end = switch_motor.run_until_stalled(-500, duty_limit=50)

# The full switch motion ranges 270 degrees. Everything beyond that
# is play towards the endstops, equal in both directions. Since we
# are currently at the left endpoint, we can reset the angle
# accordingly. This way, the functions # are simply at the
# relative positions 0, 90, 180, 270.
switch_motor.reset_angle(-(right_end - left_end - 270) / 2)


def switch_target(target_angle):
    # Try up to 5 times.
    for i in range(5):

        # Keep track of how long we've tried.
        watch = StopWatch()
        switch_motor.run_target(SWITCH_SPEED, target, wait=False)

        # Wait until the stopwatch times out.
        while watch.time() < 2000:
            wait(10)
            # We're done if the motor is on target, so exit
            # this function.
            if switch_motor.control.done():
                return

        # Otherwise, we got stuck, so try wiggling around to
        # release it.
        print("Getting unstuck.")
        switch_motor.run_target(SWITCH_SPEED, 0, wait=False)
        wait(1500)
        switch_motor.run_target(SWITCH_SPEED, 270, wait=False)
        wait(1500)


while True:

    # Check which buttons are pressed
    wait(10)
    pressed = remote.buttons.pressed()

    # If the center button is pressed, process the
    # corresponding command.
    if Button.CENTER in pressed:

        # Stop driving
        right_motor.stop()
        left_motor.stop()
        function_motor.stop()

        # Go through the commands.
        for button, command in COMMANDS.items():

            # Check if the command has a matching button.
            if button in pressed:

                # Now we can unpack the command.
                name, target, color = command

                # Execute command.
                print("Selected:", name)
                remote.light.on(color)
                switch_target(target)

                # Wait for the button to be released.
                while button in remote.buttons.pressed():
                    wait(10)

    # Activate function_motor motor based on the red buttons.
    if Button.LEFT in pressed:
        function_motor.dc(FUNCTION_POWER)
    elif Button.RIGHT in pressed:
        function_motor.dc(-FUNCTION_POWER)
    else:
        function_motor.stop()

    # Choose drive speed based on +/- buttons.
    left_speed = 0
    right_speed = 0
    if Button.LEFT_PLUS in pressed:
        left_speed += DRIVE_SPEED
    if Button.LEFT_MINUS in pressed:
        left_speed -= DRIVE_SPEED
    if Button.RIGHT_PLUS in pressed:
        right_speed += DRIVE_SPEED
    if Button.RIGHT_MINUS in pressed:
        right_speed -= DRIVE_SPEED

    # Activate the driving motors.
    left_motor.run(left_speed)
    right_motor.run(right_speed)

Credits

This program was inspired by Pybricks user AVCampos’ program first shared on Eurobricks. Be sure to check out his code and video for additional inspiration.

And thanks to Jim van Gulik who lent his bulldozer to the Pybricks team to make this program and video.

Building instructions

• Building instructions part 1
• Building instructions part 2

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This project was submitted by The Pybricks Team.