Running LED Knight Rider using Arduino

 Schematic

 The code:

int ledPins[] = {13, 12, 11, 10, 9, 8, 7, 6,5,4};

int numLEDs = sizeof(ledPins) / sizeof(ledPins[0]);

int delayTime = 80; // Waktu tunda dalam milidetik

void setup() {

  for (int i = 0; i < numLEDs; i++) {

    pinMode(ledPins[i], OUTPUT);

  }

}

void loop() {

  for (int i = 0; i < numLEDs; i++) {

    digitalWrite(ledPins[i], HIGH);

    delay(delayTime);

    digitalWrite(ledPins[i], LOW);

  }

  for (int i = numLEDs - 1; i >= 0; i--) {

    digitalWrite(ledPins[i], HIGH);

    delay(delayTime);

    digitalWrite(ledPins[i], LOW);

  }

}

Use Arduino as Bateray AA Checker

 Schematic

 

 

Maximum input voltage measurement is 5 volt as maximum internal ADC in IC Atmega328. If want to expand measurement can use voltage divider circuit.  

The code:

#include <Wire.h>

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);  // Alamat I2C untuk LCD 16x2

const int sensorPin = A0;  // Pin sensor tegangan

const int redLedPin = 8;   // Pin LED merah

const int yellowLedPin = 9;  // Pin LED kuning

const int greenLedPin = 10;  // Pin LED hijau

void setup() {

  lcd.begin(16, 2);  // Inisialisasi LCD

  lcd.backlight();   // Aktifkan backlight LCD

  pinMode(redLedPin, OUTPUT);

  pinMode(yellowLedPin, OUTPUT);

  pinMode(greenLedPin, OUTPUT);

}

void loop() {

  // Baca tegangan dari sensor

  int sensorValue = analogRead(sensorPin);

  // Konversi nilai sensor menjadi tegangan (0-5V)

  float voltage = sensorValue * (5.0 / 1023.0);

  // Tampilkan tegangan di LCD

  lcd.clear();

  lcd.setCursor(0, 0);

  lcd.print("Tegangan: ");

  lcd.print(voltage);

  lcd.print("V");

  lcd.setCursor(0, 1);

  lcd.print("Sensor: ");

  lcd.print(sensorValue);

  lcd.print(" ADC");

  // Tentukan warna LED sesuai dengan rentang tegangan

  if (voltage >= 0.0 && voltage <= 0.6) {

    digitalWrite(redLedPin, HIGH);

    digitalWrite(yellowLedPin, LOW);

    digitalWrite(greenLedPin, LOW);

  } else if (voltage > 0.6 && voltage <= 1.2) {

    digitalWrite(redLedPin, LOW);

    digitalWrite(yellowLedPin, HIGH);

    digitalWrite(greenLedPin, LOW);

  } else if (voltage > 1.2 ) {

    digitalWrite(redLedPin, LOW);

    digitalWrite(yellowLedPin, LOW);

    digitalWrite(greenLedPin, HIGH);

  }

  delay(1000);  // Tunda selama 1 detik sebelum membaca ulang tegangan

}