This test demonstrates measuring distance in cm

ultrasonicSensorTest.swift

/// EV3 Ultrasonic Sensor Sample
/// The robot advances forward until the ultrasonic sensor detects an object within 50 cm.
/// It then stops, plays a tone, and displays a message for two seconds.

import RobotKit

// Constants to adjust.
let ultrasonicSensorPort = EV3InputPort.one
let motorsPorts: EV3OutputPorts = [.A]

// Initializes a new EV3Robot instance through which all device communication happens.
let robot = try EV3Robot()

// Provides access to the ultrasonic sensor at the given port.
guard let sensor = robot.ultrasonicSensor(atPort: ultrasonicSensorPort) else {
	fatalError("Can't find the ultrasonic sensor!")
}

// Provides access to the motors at the given ports.
let motors = robot.motors(atPorts: motorsPorts)

// Drives the motors forward simultaneously at 40% speed.
motors.setSpeed(40)

// Keeps on driving forward until we're <= 50 cm from an obstacle.
sensor.waitUntilDistanceIs(.lessThanOrEqualTo, threshold: 0.5)

// Stops the motors and applies the brakes.
motors.stop(applyBrakes: true)

// Plays a 1000 Hz tone for 0.5 seconds.
robot.sound.playTone(frequency: 1000, duration: 500)

// Clears the window and displays a message for 2 seconds.
robot.window.clear()
robot.window.drawText("Mission accomplished!", fontSize: .small, at: Point(x: 2, y: 60), color: .black)

wait(seconds: 2)