Ultimate TTP224 Touch Sensor Guide: 4-Channel Capacitive Control Without Pressing

				
					// Define pins
const int touchPin1 = 2;    // TTP224 S1 → D2 (Control LED1)
const int touchPin2 = 3;    // TTP224 S2 → D3 (Control LED2)
const int touchPin3 = 4;    // TTP224 S3 → D4 (Control Fan: Toggle on/off, no time limit)
const int touchPin4 = 5;    // TTP224 S4 → D5 (Turn off all devices at once)
const int led1Pin = 6;      // LED1 → D6
const int led2Pin = 7;      // LED2 → D7
const int fanPin = 8;       // Small fan positive pole → D8 (No transistor needed)

// Define device state variables
bool led1State = LOW;       // LED1 initial state: Off
bool led2State = LOW;       // LED2 initial state: Off
bool fanState = LOW;        // Fan initial state: Stop

// Touch debounce variables (enhanced for stable LED)
unsigned long lastTouchTime1 = 0;
unsigned long lastTouchTime2 = 0;
unsigned long lastTouchTime3 = 0;
unsigned long lastTouchTime4 = 0;
const unsigned long debounceDelay = 400;  // Debounce time 400ms for anti-interference
bool lastTouch1State = LOW;  // Record last touch state for anti-interference
bool lastTouch2State = LOW;
bool lastTouch3State = LOW;
bool lastTouch4State = LOW;

void setup() {
  // Initialize pin modes
  pinMode(touchPin1, INPUT);
  pinMode(touchPin2, INPUT);
  pinMode(touchPin3, INPUT);
  pinMode(touchPin4, INPUT);
  pinMode(led1Pin, OUTPUT);
  pinMode(led2Pin, OUTPUT);
  pinMode(fanPin, OUTPUT);
  
  // Initial state: All devices are off
  digitalWrite(led1Pin, led1State);
  digitalWrite(led2Pin, led2State);
  digitalWrite(fanPin, fanState);
  
  // Serial initialization (optional, for debugging status)
  Serial.begin(9600);
  Serial.println("Device started, touch corresponding buttons to control");
}

void loop() {
  // Read current touch states (TTP224 outputs high level when touched)
  bool currentTouch1 = digitalRead(touchPin1);
  bool currentTouch2 = digitalRead(touchPin2);
  bool currentTouch3 = digitalRead(touchPin3);
  bool currentTouch4 = digitalRead(touchPin4);
  unsigned long currentTime = millis();

  // -------------------------- Enhanced LED1 Control (Stable) --------------------------
  // Double confirm touch state to avoid interference
  if (currentTouch1 == HIGH && lastTouch1State == HIGH && currentTime - lastTouchTime1 > debounceDelay) {
    led1State = !led1State;
    digitalWrite(led1Pin, led1State);
    lastTouchTime1 = currentTime;
    Serial.print("LED1 State: ");
    Serial.println(led1State ? "On" : "Off");
    // Reset touch state to avoid repeated trigger
    lastTouch1State = LOW;
  } else if (currentTouch1 == LOW) {
    lastTouch1State = LOW;
  } else {
    lastTouch1State = HIGH;
  }

  // -------------------------- Enhanced LED2 Control (Stable) --------------------------
  if (currentTouch2 == HIGH && lastTouch2State == HIGH && currentTime - lastTouchTime2 > debounceDelay) {
    led2State = !led2State;
    digitalWrite(led2Pin, led2State);
    lastTouchTime2 = currentTime;
    Serial.print("LED2 State: ");
    Serial.println(led2State ? "On" : "Off");
    lastTouch2State = LOW;
  } else if (currentTouch2 == LOW) {
    lastTouch2State = LOW;
  } else {
    lastTouch2State = HIGH;
  }

  // -------------------------- Fan Toggle Control (No Time Limit) --------------------------
  if (currentTouch3 == HIGH && lastTouch3State == HIGH && currentTime - lastTouchTime3 > debounceDelay) {
    fanState = !fanState;  // Toggle fan on/off
    digitalWrite(fanPin, fanState);
    lastTouchTime3 = currentTime;
    Serial.print("Fan State: ");
    Serial.println(fanState ? "Running" : "Stopped");
    lastTouch3State = LOW;
  } else if (currentTouch3 == LOW) {
    lastTouch3State = LOW;
  } else {
    lastTouch3State = HIGH;
  }

  // -------------------------- One-Click Turn Off All --------------------------
  if (currentTouch4 == HIGH && lastTouch4State == HIGH && currentTime - lastTouchTime4 > debounceDelay) {
    led1State = LOW;
    led2State = LOW;
    fanState = LOW;
    digitalWrite(led1Pin, led1State);
    digitalWrite(led2Pin, led2State);
    digitalWrite(fanPin, fanState);
    lastTouchTime4 = currentTime;
    Serial.println("All devices have been turned off");
    lastTouch4State = LOW;
  } else if (currentTouch4 == LOW) {
    lastTouch4State = LOW;
  } else {
    lastTouch4State = HIGH;
  }
}