SWITCH_Momentary_to_Maintained

/* One side of switch to 5V
 * Other side to Arduino button pin 5 but
 * put resistor on same button pin that leads to GND
 * then add LED (short side cathode to that pin
 * with other LED side leading to LED pin 6
 */

#define LED 6 // LED PIN
#define BUTTON 5 // PUSHBUTTON INPUT PIN
int led = 6;
int button= 5;
int val = 0;
int old_val = 0;
int state = 0;

void setup() {
pinMode(button, INPUT);
pinMode(led, OUTPUT);
}

void loop() {
val = digitalRead(BUTTON); // READ INPUT

// CHECK TRANSITION
if ((val == HIGH) && (old_val == LOW)) {
state = 1 - state; // CHANGE STATE
delay(10);

}

old_val = val; // VAL IS NOW OLD
if (state == 1) {
  digitalWrite(led,HIGH);

}
else {
digitalWrite(led, LOW); // turn LED OFF
}
}