Touch Sensor Light Switch using Arduino

1. Touch Sensor Light Switch

2. Components
• Arduino
• Joystick module (with X, Y analog output)
• 2 LEDs
• 2 resistors
• Breadboard and jumper wires

3. Connection
Component Arduino Pin
TTP223 VCC 5V
TTP223 GND GND
TTP223 OUT D2
LED Anode D9 (via 220Ω resistor)
LED Cathode GND

4. Working Principle
• Moving the joystick left/right controls one
LED; up/down controls the other.
• The joystick outputs analog values that the
Arduino reads using analogRead().

5. Code
const int touchPin = 2;
const int ledPin = 9;
bool ledState = false;
void setup() {
pinMode(touchPin, INPUT);
pinMode(ledPin, OUTPUT);
Serial.begin(9600);
}
void loop() {
static bool lastTouch = LOW;
bool currentTouch =
digitalRead(touchPin);
if (currentTouch == HIGH &&
lastTouch == LOW) {
ledState = !ledState;
digitalWrite(ledPin, ledState);
delay(300); // Debounce delay
}
lastTouch = currentTouch;
}

6. Circuit Diagram

7. Outcome
• Understanding analog signals
• Mapping analog input to output action
• Basic control interface

8. Application
• Touch-based night lamps
• DIY smart switches
• Interactive exhibits
• No-contact switches for hygiene purposes