Wind Turbine

This miniature wind turbine shows the power and limitations of this renewable energy source. In the sample code, you'll see how much voltage this mini turbine produces, and the estimated rotations per minute (rpm) of the turbine.

 

This design is part of my journey to 52 projects in 2025. I document this process on YouTube and you can see the video here:

 

Here is the sample code (uses an LCD screen):

#include <LiquidCrystal.h>
// === TURBINE VARIABLES ===
const int motorPin = A0;
int analogValue;
float motorSpeed; // Motor speed in RPM
const float Kv = 6666.67;
float Voltage;
float MaxSpeed = 0;
// === LCD SETUP ===
const int rs = 12;
const int en = 11;
const int d4 = 5;
const int d5 = 4;
const int d6 = 3;
const int d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
// === BUTTON SETUP ===
const int buttonPin = 6;
int buttonState = 0;
bool is_pressed = false;
int buttonlevel = 0;
// === AVERAGE CALCULATION ===
const int NUM_READINGS = 50;
float readings[NUM_READINGS];
int readIndex = 0;
int count = 0;
float total = 0;
float average = 0;
void computeAvg(float newReading) {
  total -= readings[readIndex];
  readings[readIndex] = newReading;
  total += readings[readIndex];
  readIndex = (readIndex + 1) % NUM_READINGS;
  if (count < NUM_READINGS) count++;
  average = total / count;
}
void setup() {
  Serial.begin(9600);
  lcd.begin(16, 2);
  pinMode(buttonPin, INPUT);
  // Initialize readings array
  for (int i = 0; i < NUM_READINGS; i++) {
    readings[i] = 0;
  }
}
void loop() {
  analogValue = analogRead(motorPin);
  buttonState = digitalRead(buttonPin);
  // Convert analog to voltage
  Voltage = (analogValue * 5.0) / 1023.0;
  // Convert voltage to RPM
  motorSpeed = Voltage * Kv;
  // Track max speed
  if (motorSpeed > MaxSpeed) {
    MaxSpeed = motorSpeed;
  }
  // Update moving average
  computeAvg(motorSpeed);
  // Handle button press
  if (buttonState == HIGH && is_pressed == false) {
    buttonlevel = (buttonlevel + 1) % 4; // 4 modes: 0–3
    is_pressed = true;
    delay(200); // Debounce
  } else if (buttonState == LOW) {
    is_pressed = false;
  }
  // Display different information based on buttonlevel
  lcd.clear();
  switch (buttonlevel) {
    case 0:
      lcd.print("Max Speed:");
      lcd.setCursor(0, 1);
      lcd.print(MaxSpeed, 1);
      lcd.print(" RPM");
      break;
case 1:
  lcd.print("Current Voltage:");
  lcd.setCursor(0, 1);
  lcd.print(Voltage, 2);
  lcd.print(" V");
  break;

case 2:
  lcd.print("Current Speed:");
  lcd.setCursor(0, 1);
  lcd.print(motorSpeed, 1);
  lcd.print(" RPM");
  break;

case 3:
  lcd.print("Avg Speed:");
  lcd.setCursor(0, 1);
  lcd.print(average, 1);
  lcd.print(" RPM");
  break;

  }
  // Optional serial monitoring
  Serial.print("Voltage: "); Serial.print(Voltage, 2);
  Serial.print(" V | Speed: "); Serial.print(motorSpeed, 1);
  Serial.print(" RPM | Avg: "); Serial.print(average, 1);
  Serial.print(" RPM | Max: "); Serial.println(MaxSpeed, 1);
  delay(100);
}