The sweep on the left is what the scanner is doing while you read this. Each tick mark is one of the samples get_samples() hands you. The full coordinate frame and array layout live on the LiDAR hardware page.

• Index 0 is dead ahead; get_num_samples() // 2 is directly behind. The array sweeps clockwise: 720 samples in the sim, ~1440 on the car, so always index relative to the length.
• Samples come back in centimetres. A 0 means no return inside the range gate.
• One scan arrives every ~33 ms. Reading it inside update() is fast enough for any closed-loop controlleri you'll write.

import racecar_core

rc = racecar_core.create_racecar()

SIDE_TIME = 1.0   # seconds per straight leg
TURN_TIME = 0.7   # seconds per 90-degree turn
SPEED = 0.25      # 25% throttle
TURN = 1.0        # full lock

timer = 0.0
leg = 0           # 8 legs: even legs drive straight, odd legs turn

def start():
    global timer, leg
    timer, leg = 0.0, 0
    rc.drive.stop()

def update():
    global timer, leg
    if leg >= 8:                     # four straights + four turns
        rc.drive.stop()
        return
    timer += rc.get_delta_time()     # seconds since the last frame
    if leg % 2 == 0:
        rc.drive.set_speed_angle(SPEED, 0)
        if timer > SIDE_TIME:
            leg, timer = leg + 1, 0.0
    else:
        rc.drive.set_speed_angle(SPEED, TURN)
        if timer > TURN_TIME:
            leg, timer = leg + 1, 0.0

rc.set_start_update(start, update)
rc.go()