❤️ Love Detector

Project

Can electronics measure love? Probably not... but they can make a pretty convincing light show!

In this project, you'll build a Love Detector using an Arduino, a touch sensor, and an RGB LED strip. Touch the sensor to trigger colorful LED animations while a companion website calculates your totally scientific love score.

Experiment with different touches and see if true love is hiding in your fingertips!

Love Machine Site

🔌 Wires

Arduino Pin	Component	Component Pin
3V	Touch Sensor	VCC
GND	Touch Sensor	GND
D7	Touch Sensor	OUT
5V	RGB LED Strip	5V
GND	RGB LED Strip	GND
D3	RGB LED Strip	DIN

💻 Code

#include <FastLED.h>

#define LED_PIN 3
#define TOUCH_PIN 7
#define NUM_LEDS 30
#define LED_TYPE WS2812B
#define COLOR_ORDER GRB
#define BRIGHTNESS 20

CRGB leds[NUM_LEDS];

bool lastTouchState = LOW;
String inputLine;

void setStripColor(uint8_t red, uint8_t green, uint8_t blue, uint8_t loveLevel) {
  fill_solid(leds, NUM_LEDS, CRGB::Black);

  for (uint8_t i = 0; i < loveLevel && i < NUM_LEDS; i++) {
    leds[i] = CRGB(red, green, blue);
  }

  FastLED.show();
}

bool parseRgbCommand(const String& line, uint8_t& red, uint8_t& green, uint8_t& blue, uint8_t& loveLevel) {
  if (!line.startsWith("R-G-B")) {
    return false;
  }

  int firstNumber = -1;
  for (int i = 0; i < line.length(); i++) {
    if (isDigit(line[i])) {
      firstNumber = i;
      break;
    }
  }

  if (firstNumber < 0) {
    return false;
  }

  int values[4] = {0, 0, 0, NUM_LEDS};
  int valueIndex = 0;
  int currentValue = 0;
  bool readingNumber = false;

  for (int i = firstNumber; i <= line.length(); i++) {
    char character = i < line.length() ? line[i] : ',';

    if (isDigit(character)) {
      currentValue = currentValue * 10 + (character - '0');
      readingNumber = true;
      continue;
    }

    if (readingNumber) {
      if (valueIndex >= 4) {
        return false;
      }

      values[valueIndex] = constrain(currentValue, 0, 255);
      valueIndex++;
      currentValue = 0;
      readingNumber = false;
    }
  }

  if (valueIndex < 3) {
    return false;
  }

  red = values[0];
  green = values[1];
  blue = values[2];
  loveLevel = constrain(values[3], 0, NUM_LEDS);
  return true;
}

void handleSerialLine(String line) {
  line.trim();

  uint8_t red;
  uint8_t green;
  uint8_t blue;
  uint8_t loveLevel;

  if (parseRgbCommand(line, red, green, blue, loveLevel)) {
    setStripColor(red, green, blue, loveLevel);
    Serial.print("OK ");
    Serial.print(red);
    Serial.print(",");
    Serial.print(green);
    Serial.print(",");
    Serial.print(blue);
    Serial.print(" LOVE ");
    Serial.println(loveLevel);
  } else if (line.length() > 0) {
    Serial.print("ERR ");
    Serial.println(line);
  }
}

void readSerialInput() {
  while (Serial.available() > 0) {
    char incoming = Serial.read();

    if (incoming == '\n') {
      handleSerialLine(inputLine);
      inputLine = "";
    } else if (incoming != '\r') {
      inputLine += incoming;
    }
  }
}

void setup() {
  pinMode(TOUCH_PIN, INPUT);
  Serial.begin(115200);

  FastLED.addLeds<LED_TYPE, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS);
  FastLED.setBrightness(BRIGHTNESS);
  setStripColor(0, 0, 0, 0);
}

void loop() {
  readSerialInput();

  bool touchState = digitalRead(TOUCH_PIN);
  if (touchState == HIGH && lastTouchState == LOW) {
    Serial.println("LOVE");
    delay(35);
  }

  lastTouchState = touchState;
}

Love Machine Website Code

Try Changing the Code

Experiment with:

• Different LED colors.
• Faster or slower animations.
• Rainbow effects.
• Sparkle patterns.
• Your own love messages on the website.

📝 Memories