Capacitive Touch Toggle

capacitiveTouchToggle.ino

#include <ADCTouch.h>
// ADCTouch can be installed in the library manager
// Procedure explained in https://www.arduino.cc/en/Guide/Libraries#toc3

int ref0;                   // reference values to remove offset
bool toggle = 0;
bool old_touch_state = 0;

void setup() {
    Serial.begin(115200*2);
    ref0 = ADCTouch.read(A0, 500);    // reference values
} 

void loop() {    
    int value0 = ADCTouch.read(A0);   // no second parameter
    value0 -= ref0;                   // remove offset

    bool new_touch_state = 0;         // default value (bool can only be 0 or 1)
    if (value0 > 40)                  // threshold to decide if a touch event happened
        new_touch_state = 1;          // 1 == true

    if (old_touch_state == 0  &&  new_touch_state == 1) {
        toggle = !toggle;             // '!' is an inverting operator
    }

    Serial.println(toggle);           //send the boolean: pressed or not pressed
    old_touch_state = new_touch_state; // backup
}

PS: Serial.begin(115200*2); is not mandatory but it helps displaying faster. You just need to pick the right baud rate in the serial plotter: 230400 (=115200*2).