This project was submitted by The Pybricks Authors.
Make the truck drive around autonomously using sensors.
Selecting a sensor
This project will work with any sensor that can measure distance.
This program builds on the basic driving example. It makes the truck back up and turn when it detects an obstacle.
from pybricks.pupdevices import Motor, ColorDistanceSensor from pybricks.parameters import Port, Direction, Stop from pybricks.tools import wait # Initialize the motors and sensor. steer = Motor(Port.C) front = Motor(Port.A, Direction.COUNTERCLOCKWISE) rear = Motor(Port.B, Direction.COUNTERCLOCKWISE) sensor = ColorDistanceSensor(Port.D) # Lower the acceleration so the car starts and stops realistically. front.control.limits(acceleration=1000) rear.control.limits(acceleration=1000) # Find the steering endpoint on the left and right. The difference between them # is the total angle it takes to go from left to right. The middle is in between. left_end = steer.run_until_stalled(-200, then=Stop.HOLD) right_end = steer.run_until_stalled(200, then=Stop.HOLD) # We are now at the right limit. We reset the motor angle to the limit value, # so that the angle is 0 when the steering mechanism is centered. limit = (right_end - left_end)//2 steer.reset_angle(limit) steer.run_target(speed=200, target_angle=0, then=Stop.COAST) # Given a motor speed (deg/s) and a steering motor angle (deg), this function # makes the car move at the desired speed and turn angle. The car keeps moving # until you give another drive command. def drive(drive_motor_speed, steer_angle): # Start running the drive motors front.run(drive_motor_speed) rear.run(drive_motor_speed) # Limit the steering value for safety, and then start the steer motor. limited_angle = max(-limit, min(steer_angle, limit)) steer.run_target(200, limited_angle, wait=False) # Keep driving. while True: # Turn around if an obstacle is detected. if sensor.distance() <= 70: # Pivot a few times. for i in range(2): # Backward left. drive(-800, -90) wait(2000) # Forward right. drive(800, 90) wait(1500) else: # Otherwise just keep driving forward. drive(800, 0)