Light on/off by clapping

1#define signalToRelayPin 13
2#define sensorPin 2
3
4int lastSoundValue;
5int  soundValue;
6long lastNoiseTime = 0;
7long currentNoiseTime = 0;
8long lastLightChange  = 0;
9int relayStatus = HIGH;
10
11void setup() {
12  pinMode(sensorPin, INPUT);
13  pinMode(signalToRelayPin, OUTPUT);
14}
15
16void loop() {
17  soundValue =  digitalRead(sensorPin);
18  currentNoiseTime = millis();
19
20  if (soundValue  == 1) { // if there is currently a noise
21
22    if (
23      (currentNoiseTime  > lastNoiseTime + 200) && // to debounce a sound occurring in more than a loop cycle  as a single noise
24      (lastSoundValue == 0) &&  // if it was silent before
25      (currentNoiseTime < lastNoiseTime + 800) && // if current clap is less than  0.8 seconds after the first clap
26      (currentNoiseTime > lastLightChange +  1000) // to avoid taking a third clap as part of a pattern
27    ) {
28
29      relayStatus  = !relayStatus;
30      digitalWrite(signalToRelayPin, relayStatus);
31      lastLightChange  = currentNoiseTime;
32     }
33
34     lastNoiseTime = currentNoiseTime;
35  }
36
37  lastSoundValue = soundValue;
38}