ESP32 Touch pin

from https://randomnerdtutorials.com/esp32-touch-pins-arduino-ide/

Take a look at your board pinout to locate the 10 different touch sensors – the touch sensitive pins are highlighted in pink color.

Let’s see how that function works by using an example from the library. In the Arduino IDE, go to File > Examples > ESP32 > Touch and open the TouchRead sketch.

// ESP32 Touch Test
// Just test touch pin - Touch0 is T0 which is on GPIO 4.

void setup() {
  Serial.begin(115200);
  delay(1000); // give me time to bring up serial monitor
  Serial.println("ESP32 Touch Test");
}

void loop() {
  Serial.println(touchRead(4));  // get value of Touch 0 pin = GPIO 4
  delay(1000);
}