Embedded Files
In this project extends P001: Light a Flag Outside to use 2 LEDs, and simulate the police lights. Goals:
Understand the basic usage of an LED
Learn the digital output concept
Apply digital output on both Micro:bit and Arduino
Simple repetition logic using of loops
Motivate the need to use Function
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Story 1: "Set the Police Lights"
Story 1: "Set the Police Lights"
Connect the external red-blue LED, understand physical wiring in practice
Story 2: "The Alternating Police Flash"
Story 2: "The Alternating Police Flash"
Use digitalWrite to output a digital (0 or 1) signal
Alternate the Red-Blue LEDs in a steady pattern
Bi -> Bo -> Bi -> Bo -> ...
Micro:bit Codes
Micro:bit Codes
def on_forever():
# Red ON, Blue OFF
pins.digital_write_pin(DigitalPin.P1, 1)
pins.digital_write_pin(DigitalPin.P2, 0)
basic.pause(500)
# Red OFF, Blue ON
pins.digital_write_pin(DigitalPin.P1, 0)
pins.digital_write_pin(DigitalPin.P2, 1)
basic.pause(500)
basic.forever(on_forever)
Arduino Codes
Arduino Codes
void setup()
{
pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
}
void loop() {
digitalWrite(2, HIGH); // Red ON
digitalWrite(3, LOW); // Blue OFF
delay(500);
digitalWrite(2, LOW); // Red OFF
digitalWrite(3, HIGH); // Blue ON
delay(500);
}
Story 3: "The High-Intensity Police Flash"
Story 3: "The High-Intensity Police Flash"
Challenging fun task, motivating using looping and function
Blink in realistic police light pattern:
Red-Red-Red (Fast) -> Blue-Blue-Blue (Fast) -> ...
Micro:bit Codes
Micro:bit Codes
def on_forever():
# --- START RED FLASHES ---
# Red Flash 1
pins.digital_write_pin(DigitalPin.P1, 1)
basic.pause(150)
pins.digital_write_pin(DigitalPin.P1, 0)
basic.pause(150)
# Red Flash 2
pins.digital_write_pin(DigitalPin.P1, 1)
basic.pause(150)
pins.digital_write_pin(DigitalPin.P1, 0)
basic.pause(150)
# Red Flash 3
pins.digital_write_pin(DigitalPin.P1, 1)
basic.pause(150)
pins.digital_write_pin(DigitalPin.P1, 0)
basic.pause(150)
# Gap between colors
basic.pause(500)
# --- START BLUE FLASHES ---
# Blue Flash 1
pins.digital_write_pin(DigitalPin.P2, 1)
basic.pause(150)
pins.digital_write_pin(DigitalPin.P2, 0)
basic.pause(150)
# Blue Flash 2
pins.digital_write_pin(DigitalPin.P2, 1)
basic.pause(150)
pins.digital_write_pin(DigitalPin.P2, 0)
basic.pause(150)
# Blue Flash 3
pins.digital_write_pin(DigitalPin.P2, 1)
basic.pause(150)
pins.digital_write_pin(DigitalPin.P2, 0)
basic.pause(150)
# Final gap before loop restarts
basic.pause(500)
basic.forever(on_forever)
def flash_blue():
for index in range(3):
pins.digital_write_pin(DigitalPin.P2, 1)
basic.pause(150)
pins.digital_write_pin(DigitalPin.P2, 0)
basic.pause(150)
def flash_red():
for index2 in range(3):
pins.digital_write_pin(DigitalPin.P1, 1)
basic.pause(150)
pins.digital_write_pin(DigitalPin.P1, 0)
basic.pause(150)
def on_forever():
flash_red()
basic.pause(500)
# Short pause between colors
flash_blue()
basic.pause(500)
basic.forever(on_forever)
Arduino Codes
Arduino Codes
void setup() {
pinMode(2, OUTPUT); // Red LED
pinMode(3, OUTPUT); // Blue LED
}
void loop() {
// --- RED SECTION ---
// Flash 1
digitalWrite(2, HIGH);
delay(100);
digitalWrite(2, LOW);
delay(100);
// Flash 2
digitalWrite(2, HIGH);
delay(100);
digitalWrite(2, LOW);
delay(100);
// Flash 3
digitalWrite(2, HIGH);
delay(100);
digitalWrite(2, LOW);
delay(100);
delay(300); // Gap between colors
// --- BLUE SECTION ---
// Flash 1
digitalWrite(3, HIGH);
delay(100);
digitalWrite(3, LOW);
delay(100);
// Flash 2
digitalWrite(3, HIGH);
delay(100);
digitalWrite(3, LOW);
delay(100);
// Flash 3
digitalWrite(3, HIGH);
delay(100);
digitalWrite(3, LOW);
delay(100);
delay(300); // Gap before loop restarts
}
void setup()
{
pinMode(2, OUTPUT); // Red LED
pinMode(3, OUTPUT); // Blue LED
}
void flashColor(int pin) {
for (int i = 0; i < 3; i++) {
digitalWrite(pin, HIGH);
delay(100);
digitalWrite(pin, LOW);
delay(100);
}
}
void loop() {
flashColor(2); // Flash Red 3 times
delay(300); // Gap
flashColor(3); // Flash Blue 3 times
delay(300); // Gap
}
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 will be the pain if requesting to change the blinking speed for the solution without using function?
What pros and cons to use Function?
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