Embedded Files
In this project, you will connect an external LED to Micro:bit and use it as a tiny light flag. Through hands-on stories, you will learn the main concept of digital output and how to program an external device by digital signal. You will also see how the same concept applies when using Arduino, giving you a broader understanding of electronics and programming. Goals:
Understand the basic usage of an LED
Learn the digital output concept
Apply digital output on both Micro:bit and Arduino
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Story 1: "Set the Outside Flag"
Story 1: "Set the Outside Flag"
Connect the first external LED, understand physical wiring in practice
Story 2: "Blink the Light Flag"
Story 2: "Blink the Light Flag"
Use digitalWrite to output a digital (0 or 1) signal
Micro:bit Codes
Micro:bit Codes
def on_button_pressed_a():
pins.digital_write_pin(DigitalPin.P1, 1)
input.on_button_pressed(Button.A, on_button_pressed_a)
def on_button_pressed_b():
pins.digital_write_pin(DigitalPin.P1, 0)
input.on_button_pressed(Button.B, on_button_pressed_b)
def on_forever():
pins.digital_write_pin(DigitalPin.P1, 1)
basic.pause(1000)
pins.digital_write_pin(DigitalPin.P1, 0)
basic.pause(1000)
basic.forever(on_forever)
Arduino Codes
Arduino Codes
void setup()
{
pinMode(2, OUTPUT);
}
void loop()
{
digitalWrite(2, HIGH);
delay(1000);
digitalWrite(2, LOW);
delay(1000);
}
Story 3: "Blinking in the Beats"
Story 3: "Blinking in the Beats"
Challenging fun task, blink in dynamic pattern, motivating the need of using Functions
Blinking the LED to follow the musical rhythms
TEMPO 120 BPMQ-NOTE 500msH-NOTE 1000msTOTAL CYCLE 3.0s
Micro:bit Codes
Micro:bit Codes
def on_forever():
# --- STOMP 1 ---
pins.digital_write_pin(DigitalPin.P1, 1)
basic.pause(300)
pins.digital_write_pin(DigitalPin.P1, 0)
basic.pause(200)
# --- STOMP 2 ---
pins.digital_write_pin(DigitalPin.P1, 1)
basic.pause(300)
pins.digital_write_pin(DigitalPin.P1, 0)
basic.pause(200)
# --- CLAP! ---
pins.digital_write_pin(DigitalPin.P1, 1)
basic.pause(800)
pins.digital_write_pin(DigitalPin.P1, 0)
basic.pause(200)
# --- REST ---
basic.pause(1000)
basic.forever(on_forever)
def pulse(on_time: number, off_time: number):
# Turn LED on Pin 1 ON
pins.digital_write_pin(DigitalPin.P1, 1)
basic.pause(on_time)
# Turn LED on Pin 1 OFF
pins.digital_write_pin(DigitalPin.P1, 0)
basic.pause(off_time)
def on_forever():
# STOMP (1/4 beat)
pulse(300, 200)
# STOMP (1/4 beat)
pulse(300, 200)
# CLAP! (1/2 beat)
pulse(800, 200)
# REST (Silence for the remainder of the measure)
basic.pause(1000)
basic.forever(on_forever)
Arduino Codes
Arduino Codes
// Define the LED pin
const int ledPin = 2;
void setup() {
// Initialize digital pin 2 as an output
pinMode(ledPin, OUTPUT);
}
void loop() {
// STOMP (1/4 beat), total 500ms
digitalWrite(ledPin, HIGH); // LED ON
delay(300); // ON time
digitalWrite(ledPin, LOW); // LED OFF
delay(200); // OFF time
// STOMP (1/4 beat), total 500ms
digitalWrite(ledPin, HIGH); // LED ON
delay(300); // ON time
digitalWrite(ledPin, LOW); // LED OFF
delay(200); // OFF time
// CLAP! (1/2 beat), total 1000ms
digitalWrite(ledPin, HIGH); // LED ON
delay(800); // ON time
digitalWrite(ledPin, LOW); // LED OFF
delay(200); // OFF time
// REST (1/2 beat), total 1000ms
delay(1000);
}
// Define the LED pin
const int ledPin = 2;
// Function to handle the "pulse" logic
void pulse(int onTime, int offTime) {
digitalWrite(ledPin, HIGH); // Turn LED ON
delay(onTime); // Wait
digitalWrite(ledPin, LOW); // Turn LED OFF
delay(offTime); // Wait
}
void setup() {
// Initialize digital pin 2 as an output
pinMode(ledPin, OUTPUT);
}
void loop() {
// STOMP (1/4 beat), total 500ms
pulse(300, 200);
// STOMP (1/4 beat), total 500ms
pulse(300, 200);
// CLAP! (1/2 beat), total 1000ms
pulse(800, 200);
// REST (1/2 beat), total 1000ms
delay(1000);
}
Test and Fix
Test and Fix
Do they work? Any risk of ocassional or corner case faults? How to fix
Does it blink correctly?
Does it blink correctly?
void setup()
{
pinMode(2, OUTPUT);
}
void loop()
{
digitalWrite(2, HIGH);
delay(1000);
digitalWrite(2, LOW);
}
Knowledge Check
Knowledge Check
Enhance basic knowledge understanding, reflect and summarize what we have learnt
How many and what states does a digital signal have?
What happens if a LED is connected in opposite leads?
What pros and cons to use Function?
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