void setup() {pinMode(11, INPUT_PULLUP);pinMode(13, OUTPUT);Serial.begin(9600);}int ck=0;int ck2=0;
void loop() {Serial.println(digitalRead(11));if(digitalRead(11) && ck2!=digitalRead(11)){ switch(ck){ case 0: { digitalWrite(13,1); ck=1; break; } case 1: { digitalWrite(13,0); ck=0; break; } }}ck2=digitalRead(11);}