How to Use Touch Sensor TTP233: Examples, Pinouts, and Specs

The Touch Sensor TTP233 is a capacitive touch switch module designed by Adafruit. This sensor is capable of detecting touch or proximity with a simple tap or swipe of a finger. It is widely used in various applications such as interactive installations, user interfaces, and any project where touch sensing is required. The TTP233 is a versatile and reliable component that can add intuitive touch controls to your electronic projects.

• Operating Voltage: 2.0V to 5.5V
• Response Time: Max 220ms at VDD=3V
• Touch Pad Detection: Capacitive
• Output Type: Active Low (TTL compatible)
• Operating Current: 2.5uA (typical) at VDD=3V, no touch
• Interface: Digital Signal Output

To use the TTP233 touch sensor in a circuit, follow these steps:

1. Connect the VDD pin to a power supply within the range of 2.0V to 5.5V.
2. Connect the GND pin to the ground of your power supply.
3. Connect the SIG pin to a digital input pin on your microcontroller, such as an Arduino UNO.

• Ensure that the power supply voltage does not exceed the maximum rating of 5.5V to prevent damage to the sensor.
• Avoid placing the sensor in an environment with high humidity or the presence of conductive liquids, as these can trigger false touch detections.
• The touch pad area should be clean and free from any conductive materials that could interfere with the sensor's operation.
• For optimal performance, calibrate the sensor in the final installation environment to account for any parasitic capacitance.

// Include the Arduino digital I/O library
#include <Arduino.h>

// Define the touch sensor pin
const int touchPin = 2; // Connect the SIG pin of the TTP233 to digital pin 2

void setup() {
  // Initialize the touchPin as an input
  pinMode(touchPin, INPUT);
  // Begin serial communication at 9600 baud rate
  Serial.begin(9600);
}

void loop() {
  // Read the state of the touch sensor
  int touchState = digitalRead(touchPin);
  
  // Check if the sensor is touched
  if (touchState == LOW) { // Remember the sensor output is active low
    // If touched, print a message to the serial monitor
    Serial.println("Touch detected!");
  } else {
    // If not touched, print a different message
    Serial.println("No touch detected.");
  }
  
  // Small delay to avoid overwhelming the serial monitor
  delay(100);
}

• Sensor not responding to touch: Ensure that the sensor is properly powered and that the SIG pin is correctly connected to the microcontroller.
• False triggers or no detection: Check for any conductive debris or moisture on the touch pad. Also, ensure that the environment does not have excessive electrical noise.

• Double-check all connections and ensure that the sensor is not damaged.
• If using a breadboard, ensure that all connections are secure and not loose.
• Test the sensor with a multimeter to ensure it is receiving the correct voltage.
• If the sensor is still not functioning correctly, try replacing it with a new one to rule out a defective unit.

Q: Can the TTP233 sensor detect touch through materials?

A: Yes, the TTP233 can detect touch through thin, non-conductive materials like plastic or glass.

Q: Is it possible to adjust the sensitivity of the TTP233 sensor?

A: The sensitivity is not directly adjustable on the basic TTP233 module. However, some modules may have additional components or settings to adjust sensitivity.

Q: How long is the sensor's response time?

A: The maximum response time is approximately 220ms at a supply voltage of 3V.

Q: Can the TTP233 sensor work with a 3.3V logic level?

A: Yes, the TTP233 can operate at voltages as low as 2.0V, making it compatible with 3.3V logic levels.