Incremental speed control of the boost hub motors

[MichaelVerschaeve]

Hello, as explained here https://www.youtube.com/watch?v=1tds-9R2gpY it's possible to control the boost move hub with the powered up remote control. Unfortunately it's "bang bang" mode, the motors are immediately at full speed.

Luckily, it's relatively straigtforward to write some code in pybricks to connect with a remote and have incremental control over the motors with key-presses on the remote:

from pybricks.hubs import MoveHub
from pybricks.pupdevices import Remote, Motor, ColorDistanceSensor
from pybricks.parameters import Button, Color, Direction, Port, Side, Stop
from pybricks.robotics import DriveBase
from pybricks.tools import wait, StopWatch

hub = MoveHub()
left_motor = Motor(Port.A, positive_direction=Direction.CLOCKWISE)
right_motor = Motor(Port.B, positive_direction=Direction.COUNTERCLOCKWISE)
drive_base = DriveBase(left_motor, right_motor, wheel_diameter=8*6, axle_track=8*16)
head_motor = Motor(Port.D, positive_direction=Direction.CLOCKWISE)

SPEED_MAX = 500    # straight driving speed (mm/sec)
TURN_RATE_MAX = 200         # turning rate (deg/sec)
SPEED_INC = 100
TURN_RATE_INC = 40

def twitch():
    head_motor.run_target(200,45)
    head_motor.run_target(200,-45)
    head_motor.run_target(200,0)

def reset():
    head_motor.run_until_stalled(100)
    head_motor.run_angle(200,-75)
    head_motor.reset_angle(0)

#main program
reset()
try:
    # Search for a remote for 5 seconds.
    rc = Remote(timeout=5000)

    print("Connected!")
    rc.light.on(Color.GREEN)
    hub.light.on(Color.GREEN)
    #with remote
    speed = 0
    turn_rate = 0
    while True:
        pressed = ()
        #wait until button press
        while not pressed:
            pressed = rc.buttons.pressed()

        # set speed or rotation depending on the button pressed
        if Button.LEFT_PLUS in pressed:
            turn_rate += TURN_RATE_INC
        if Button.LEFT_MINUS in pressed:
            turn_rate -= TURN_RATE_INC
        if Button.LEFT in pressed:
            turn_rate = 0
        if Button.RIGHT_PLUS in pressed:
            speed += SPEED_INC
        if Button.RIGHT_MINUS in pressed:
            speed -= SPEED_INC
        if Button.RIGHT in pressed:
            speed = 0
        if Button.CENTER in pressed:
            drive_base.stop()
            twitch()
            speed = 0
            turn_rate = 0

            #apply limits
        if speed > SPEED_MAX:
            speed = SPEED_MAX
        if speed < -SPEED_MAX:
            speed = -SPEED_MAX
        if turn_rate > TURN_RATE_MAX:
            turn_rate = TURN_RATE_MAX
        if turn_rate < -TURN_RATE_MAX:
            turn_rate = -TURN_RATE_MAX

        #set drive
        drive_base.drive(speed, turn_rate)

        #wait until button release
        while pressed:
            pressed = rc.buttons.pressed()
except OSError:
    print("Could not find the remote, controlling by color sensor")
    hub.light.on(Color.RED)
    #without remote, use color sensor
    sensor = ColorDistanceSensor(Port.C)
    while True:
        if sensor.color() == Color.GREEN:
            drive_base.drive(SPEED_MAX//3,0)
        if sensor.color() == Color.YELLOW:
            drive_base.drive(0,TURN_RATE_MAX//3)
        if sensor.color() == Color.BLUE:
            drive_base.drive(0,-TURN_RATE_MAX//3)
        if sensor.color() == Color.RED:
            drive_base.stop()
            twitch()
        wait(10)

I use it to control this guy

https://robotics.benedettelli.com/lego-boost-wall-e/
but nearly identical code could probably be used to control the default Vernie The Robot model.
I also quite like I can code a fallback to control Wall-E with the color sensor if no remote is found within 5 seconds.