Introduction

The TTP223 is a capacitive touch sensor module that detects human touch through a small metal pad. This low-power module provides a digital output signal when touched and is commonly used in touch-controlled projects.

Key Features

Technical Specifications

Pin Configuration

Wiring with Arduino

// Basic Digital Connection:
// VCC → 5V
// GND → GND
// OUT → D2 (or any digital pin)

void setup() {
  pinMode(2, INPUT);
  Serial.begin(9600);
}

void loop() {
  if(digitalRead(2) == HIGH) {
    Serial.println("Touch detected!");
  }
}

Mode Selection

1. Locate the solder jumper labeled “A” on the back of the module
2. For toggle mode (touch on/off): Connect “A” to GND
3. For momentary mode (active while touched): Connect “A” to VCC
4. Default configuration is usually momentary mode

Sensitivity Adjustment

1. Locate the small capacitor near the touch pad (typically labeled C1)
2. To increase sensitivity: Replace with a smaller capacitor value
3. To decrease sensitivity: Replace with a larger capacitor value
4. Default is usually 2.2nF (222 marking)

Advanced Applications

const int relayPin = 3;
const int touchPin = 2;
bool relayState = false;

void setup() {
  pinMode(relayPin, OUTPUT);
  pinMode(touchPin, INPUT);
}

void loop() {
  if(digitalRead(touchPin) {
    relayState = !relayState;
    digitalWrite(relayPin, relayState);
    delay(200); // Debounce
  }
}

void loop() {
  if(digitalRead(2)) {
    Keyboard.press('A');
    delay(50);
    Keyboard.releaseAll();
  }
}

const int touchPins[] = {2,3,4,5};
const int numPins = 4;

void checkTouches() {
  for(int i=0; i<numPins; i++) {
    if(digitalRead(touchPins[i])) {
      Serial.print("Touch detected on pin ");
      Serial.println(i);
    }
  }
}

Troubleshooting