My Example Technic Controller

[bcfletcher]

Below is the code i created to manually drive my Lego Technic Transformation Vehicle while avoiding walls. i added the Color & Distance sensor to the front the vehicle.

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


# this code will not work with MoveHub since it does not support input() method
# Initialize the hub.
print("TechnicHub Manual Controller")
print("")
print("Commands: ")
print("       forwward: f #    (# in mm)")
print("       backward: b #    (# in mm)")
print("           turn: t #    (# in mm, negative to turn in other direction)")
print("sensor distance: d #    (# any number)")
print("            end: e #    (# any number)")


hub = TechnicHub()

SIDE_COLORS = {
    Side.TOP: Color.RED,
    Side.BOTTOM: Color.BLUE,
    Side.LEFT: Color.GREEN,
    Side.RIGHT: Color.YELLOW,
    Side.FRONT: Color.MAGENTA,
    Side.BACK: Color.BLACK,
}

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

# is up hub facing upward
print ("hub orientation=",hub.imu.up())

# check batteries 
print ("voltage=",hub.battery.voltage())
print ("current=", hub.battery.current())
left_motor.reset_angle()
right_motor.reset_angle()

# make sure your wheel_diameter and axle_track are measured correctly or the distance vehicle moves will be off
#
drive_base = DriveBase(left_motor, right_motor,wheel_diameter=33,axle_track=155)

# reset distane calculations
drive_base.reset()


up_side = hub.imu.up()
hub.light.on(SIDE_COLORS[up_side])
print(up_side)

while True: 
    
    sensorDistance = ColorDistanceSensor(Port.C).distance()
    if sensorDistance  < 40:
        print("stopped, found object")
        drive_base.stop()

    # turns can be positive or negative
    cmdStr = input("Command (f,b,t,s,e) and a # (in mm): ")
    print("Command=", cmdStr)
    if len(cmdStr.split()) == 2:
        direction=cmdStr.split()[0]
        dist=int(cmdStr.split()[1])
        if direction == 'f':
            print("forward=",dist)
            drive_base.straight(dist,Stop.HOLD,wait=False)
        elif direction ==  'b':
            print("backward=",dist)
            drive_base.straight(dist*-1,Stop.HOLD,wait=False)
        elif direction ==  't':
            print("turn=",dist)
            drive_base.turn(dist)
        elif direction == 'd':
            sensorDistance = ColorDistanceSensor(Port.C).distance()
            print("sensor distance=",sensorDistance )
        elif direction == 's':
            print("state=",drive_base.state())
        elif direction == 'e':
            print("shutdown system")
            print("Distance travelled=", drive_base.distance())
            hub.system.shutdown()
        else:
            print("unknown command")
    else:
        print("invalid command")

    #print("----drive loop=",direction)
    #print("----1 sensor distance=",ColorDistanceSensor(Port.C).distance()," state=",drive_base.state()[1])

    wait(250)
    
    # loop unless direction is backward (no sensor is facing backwards)
    if (direction != 'b') :
        while ((ColorDistanceSensor(Port.C).distance() > 40) and (drive_base.state()[1] != 0)) :
            wait(1)
        print("stopped, found object")
        drive_base.stop()

[dlech]

Very nice!

[bcfletcher]

thanks.
BTW, I think there is a documentation error.

https://docs.pybricks.com/en/latest/hubs/technichub.html

states imu.stationary() is included in TechnicHub package. But it does not appear to be a valid TechnicHub function when I try to reference it.

I ordered a 2nd Color/Distance sensor so I will update for Backwards Detection when it arrives.

I am developing on a Raspberry Pi 400 using Chromium. Works great!