Lesson 3 of 7
Outputs & Actuators
Make things happen: lights, sounds, motors, servos and displays.
Learn it
Outputs let a computer affect the real world by producing light, sound or movement.
An LED is a simple digital output: it is either on or off.
A servo motor can move to a precise angle, which is useful for robot arms and steering.
Key terms
- Actuator
- A component that turns an electrical signal into physical action.
- LED
- Light-Emitting Diode: a small, efficient digital light source.
- PWM
- Pulse-Width Modulation: controlling power by switching it on and off very quickly.
- Servo Motor
- A motor that can be set to a specific angle and hold that position.
Output Examples
Different jobs need different actuators.
- 1Warning light: A red LED flashes when a sensor detects a problem.
- 2Robot wheels: Two DC motors move the robot forwards, backwards and turn.
- 3Robot arm: Servo motors position each joint at a precise angle.
- 4Alarm: A buzzer or speaker produces sound when triggered.
Blinking an LED with PWM
pythonfrom microbit import *
# Pin 0 controls an external LED
while True:
for brightness in range(0, 1024, 64):
pin0.write_analog(brightness)
sleep(20)
for brightness in range(1023, -1, -64):
pin0.write_analog(brightness)
sleep(20)PWM rapidly switches the LED on and off. A higher average voltage makes the LED brighter, creating a smooth fade effect.
Try it
Are these statements about outputs true or false?
A servo motor is useful when you need to move to a precise angle.
PWM can only turn an LED fully on or fully off.
A buzzer is an example of an actuator.
DC motors are best for holding an exact position without extra sensors.
Challenge
You need to build a small automated gate for a model car park. Which output would you choose: a DC motor, a servo motor, or a stepper motor? Justify your answer.
Pick whichever way suits you — every mode earns the same bonus XP.
Write at least 40 more characters to submit.
Mark your own work
Guided walkthrough — 0/5 clues revealed
- Clue 1 locked — reveal it only if you get stuck.
- Clue 2 locked — reveal it only if you get stuck.
- Clue 3 locked — reveal it only if you get stuck.
- Clue 4 locked — reveal it only if you get stuck.
- Clue 5 locked — reveal it only if you get stuck.
Each clue costs 3 XP (never below 14 XP). You'd earn 28 XP right now.
Extension: Describe how you would add a safety light that turns on while the gate is moving.