20 Pieces Blue LED – 5mm Super Bright Standard LED Diodes

Description

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🔌 Description of LEDs (5 mm LED Diode)

📏 General Characteristics

• Type: LED Diode (Light Emitting Diode)
• Diameter: 5 mm
• Typical Operating Voltage:
  • Red: 1.8–2.2 V
  • Yellow: 2.0–2.2 V
  • Green: 2.0–3.2 V
  • Blue: 3.0–3.4 V
  • White: 3.0–3.4 V
• Recommended Current: 10–20 mA
• Polarity: Anode (positive, longer leg) and Cathode (negative, shorter leg)

🎨 Available Colors

• Green LED: Used to indicate active or OK status.
• Red LED: Symbolizes warnings, errors, or power.
• White LED: For illumination or neutral signaling.
• Yellow LED: Attention or standby status.
• Blue LED: Modern, often used for power-on or special status.

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🛠️ Guide to use with Arduino

🔧 Required components

• Arduino UNO (or compatible)
• Resistors 220Ω or 330Ω
• 5 mm LEDs (color of choice)
• Breadboard
• Jumper wires

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📈 Connection diagram (single LED)

Arduino PIN (es. 13) ---> Resistenza (220Ω) ---> Anodo LED
                                      |
                                  Catodo ---> GND

• Connect the long leg of the LED (anode) through a 220Ω resistor to an Arduino digital pin.
• Connect the short leg (cathode) to the GND of Arduino.

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💻 Example code: turn on an LED

// Pin a cui è collegato il LED
int ledPin = 13;

void setup() {
  pinMode(ledPin, OUTPUT); // imposta il pin come uscita
}

void loop() {
  digitalWrite(ledPin, HIGH); // accende il LED
  delay(1000);                // attende 1 secondo
  digitalWrite(ledPin, LOW);  // spegne il LED
  delay(1000);                // attende 1 secondo
}

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🧪 Example: turn on 5 LEDs of different colors

⚙️ Connection

LED	Arduino PIN	Resistor
Red	2	220Ω
Green	3	220Ω
Yellow	4	220Ω
Blue	5	330Ω
White	6	330Ω

🔤 Arduino Code for LED Sequence

int ledRosso = 2;
int ledVerde = 3;
int ledGiallo = 4;
int ledBlu = 5;
int ledBianco = 6;

void setup() {
  pinMode(ledRosso, OUTPUT);
  pinMode(ledVerde, OUTPUT);
  pinMode(ledGiallo, OUTPUT);
  pinMode(ledBlu, OUTPUT);
  pinMode(ledBianco, OUTPUT);
}

void loop() {
  digitalWrite(ledRosso, HIGH);
  delay(500);
  digitalWrite(ledRosso, LOW);

  digitalWrite(ledVerde, HIGH);
  delay(500);
  digitalWrite(ledVerde, LOW);

  digitalWrite(ledGiallo, HIGH);
  delay(500);
  digitalWrite(ledGiallo, LOW);

  digitalWrite(ledBlu, HIGH);
  delay(500);
  digitalWrite(ledBlu, LOW);

  digitalWrite(ledBianco, HIGH);
  delay(500);
  digitalWrite(ledBianco, LOW);
}

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📘 Practical Tips

• Use different resistors for each color to avoid damage: blue and white require higher values.
• If you want more control, consider using transistors o LED drivers for higher current.
• You can combine these LEDs to create a traffic light, status indicator, simple light effects.

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🧠 Advanced Experiments

• PWM (Pulse Width Modulation): Use analogWrite(pin, valore) to adjust brightness.
• Sensors: Turn on LEDs in response to light, temperature, or motion sensors.
• Light effects: Create breathing, random flashing, or music-synced effects.

Perfect! Here are 3 advanced examples of using 5mm LEDs with Arduino:

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🚦 1. Traffic Light with LEDs

🔧 Components

• 1 Red LED (Pin 2)
• 1 Yellow LED (Pin 3)
• 1 Green LED (Pin 4)
• 3 Resistors (220Ω)
• Arduino, breadboard, jumper

💡 Schematic

Connect the LEDs through resistors to pins 2, 3, 4 respectively and GND.

🧠 Code

int ledRosso = 2;
int ledGiallo = 3;
int ledVerde = 4;

void setup() {
  pinMode(ledRosso, OUTPUT);
  pinMode(ledGiallo, OUTPUT);
  pinMode(ledVerde, OUTPUT);
}

void loop() {
  digitalWrite(ledRosso, HIGH);
  delay(3000); // 3 secondi
  digitalWrite(ledRosso, LOW);
  
  digitalWrite(ledGiallo, HIGH);
  delay(1000); // 1 secondo
  digitalWrite(ledGiallo, LOW);

  digitalWrite(ledVerde, HIGH);
  delay(3000); // 3 secondi
  digitalWrite(ledVerde, LOW);
}

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🔘 2. LED Toggle with Button (on/off)

🔧 Components

• 1 LED (e.g., Blue, Pin 8)
• 1 LED Resistor (330Ω)
• 1 Button (Pin 7)
• 1 Pull-down Resistor (10kΩ)
• Arduino

🔌 Connection

• LED (Anode to Pin 8 through resistor, Cathode to GND)
• Button between Pin 7 and 5V, with pull-down between Pin 7 and GND

🧠 Code

int ledPin = 8;
int buttonPin = 7;
bool statoLED = false;
bool statoPrecedente = false;

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT);
}

void loop() {
  bool lettura = digitalRead(buttonPin);
  if (lettura == HIGH && statoPrecedente == LOW) {
    statoLED = !statoLED;
    digitalWrite(ledPin, statoLED);
    delay(200); // debounce
  }
  statoPrecedente = lettura;
}

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📱 3. LED Control via Bluetooth (from App)

🔧 Components

• LED (Red – Pin 10)
• HC-05 Bluetooth module (TX/RX)
• Arduino UNO

📲 Recommended App: Serial Bluetooth Terminal (Android) or similar

🧠 Connection

• Red LED at Pin 10 (through 220Ω resistor)
• HC-05:
  • TX ➝ RX (Pin 0 of Arduino)
  • RX ➝ TX (Pin 1 of Arduino, with voltage divider resistor)
  • VCC ➝ 5V
  • GND ➝ GND

🔥 Note: disconnect TX/RX when uploading sketch to Arduino.

🧠 Code

int ledPin = 10;
char comando;

void setup() {
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  if (Serial.available()) {
    comando = Serial.read();
    if (comando == '1') {
      digitalWrite(ledPin, HIGH);
    } else if (comando == '0') {
      digitalWrite(ledPin, LOW);
    }
  }
}

📲 Commands from app

• Send 1 ➝ LED on
• Send 0 ➝ LED off

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Perfect! The effect “breathing” (also known as fading LED) simulates the behavior of a light that slowly turns on and off, just like if it were “breathing”. It’s a great exercise to learn about PWM (Pulse Width Modulation) with Arduino.

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🌬️ Project: LED with breathing effect (fading)

🔧 Required Components

• 1 LED (preferably White, Blue or Green for a nice visual effect)
• 1 Resistor 220–330Ω
• Arduino UNO
• Breadboard and jumpers

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🔌 Connection Diagram

Component	Connection
LED Anode	Pin 9 (PWM)
LED Cathode	GND (via resistor 220Ω)

Pin 9 of Arduino supports PWM (you can see it with the symbol ~).

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💻 Arduino Code: breathing effect

int ledPin = 9;       // Pin PWM
int luminosita = 0;   // Valore PWM (0-255)
int variazione = 5;   // Incremento/decremento luminosità

void setup() {
  pinMode(ledPin, OUTPUT);
}

void loop() {
  analogWrite(ledPin, luminosita); // imposta la luminosità

  luminosita += variazione;        // cambia luminosità

  // Inverti direzione al raggiungimento di estremi
  if (luminosita <= 0 || luminosita >= 255) {
    variazione = -variazione;
  }

  delay(30); // tempo tra i cambi (più alto = respiro più lento)
}

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🧪 Additional experiments

• Modify delay(30) to make the breathing slower or faster.
• Change variazione a 1 for an even softer effect.
• Try with a RGB LED to fade through multiple colors (want an RGB example? I can give you one!)

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🎨 Variant: “sinusoidal breathing” (more natural)

For a more realistic effect, you can use the sine function to model the brightness (requires the library math.h on some Arduino versions):

int ledPin = 9;
float x = 0;

void setup() {
  pinMode(ledPin, OUTPUT);
}

void loop() {
  float valore = (sin(x) + 1.0) * 127.5; // da 0 a 255
  analogWrite(ledPin, int(valore));
  x += 0.05;
  if (x > TWO_PI) x = 0;
  delay(20);
}

This creates a softer “breathing” effect, similar to that of Apple devices or smart devices.

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Tutorial: How to use 20 Blue LED Pieces

These blue LEDs are ideal for lighting and signal projects. Useful for beginners and designers.

What you need

• 20 pieces blue 5 mm LEDs
• Suitable resistor (check the datasheet)
• Arduino or similar microcontroller
• LED connector (check the datasheet)

Steps

1. 1. Check the maximum allowed current (check the datasheet).
2. 2. Choose a suitable resistor (check the datasheet).
3. 3. Connect an LED to a digital pin of the Arduino.
4. 4. Connect the resistor between the pin and ground.
5. 5. Load the example code to blink the LED.
6. 6. Repeat for all LEDs.
7. 7. Check connections to avoid short circuits.
8. 8. Test your circuit.

Example code

```void setup() {} void loop() { for (int i = 0; i < 20; i++) { digitalWrite(i, HIGH); delay(100); digitalWrite(i, LOW); } }```

Mini project

Create an emergency signal with 5 blinking LEDs.

Common mistakes

• Connecting an LED without a resistor can damage it.
• Do not use resistors that are too large or too small.
• Ensure the maximum current is not exceeded.
• Check the multimeter of the LEDs before connection.

Recommended accessories

• 220 Ohm resistor
• Arduino UNO
• USB cable
• Multimeter

Frequently asked questions

How to choose a resistor?
Check the maximum current on the datasheet and choose a resistor that limits the current to a safe value.

Can I connect multiple LEDs in parallel?
Yes, but make sure the total current does not exceed the capacity of your power supply.

What is the difference between 5 mm and 3 mm LEDs?
5 mm LEDs are larger and brighter, 3 mm LEDs are smaller and less bright.

How do I check if an LED works?
With a multimeter, measure the diode. If it is open, the LED does not work.