Sitting Sensor

1/*
2This code is meant to send a buzzing alert if there hasn't been  light for a given period of time;
3if there is light shining in the sensor, the  alert will not go off.
4
5The intention is for someone who is sitting down to  get alerts to move every so often.
6
7******************************************************************************/
8const  int buzzer = A3;             //assigning buzzer pin
9const int lightSensor = A2;       //assigning light sensor pin
10int NOTE = 5000;                  //creating  alarm buzzer tone
11const int sitPeriod = 10000;       //defining period allowed  sitting before alert
12boolean sittingDown = false;      //setting up boolean to  check sitting down condition
13
14unsigned long SitPeriodStart;  //creating value  for start of sitting period
15unsigned long currentTime;
16
17void setup() {
18  pinMode(lightSensor, INPUT);
19  pinMode(buzzer, OUTPUT);
20  pinMode(A7, OUTPUT);            //LED is used to check conditions and that code is working
21
22  Serial.begin(9600);
23}
24
25void  loop() {
26
27  int sensorValue;
28  sensorValue = analogRead(lightSensor);      //defining  and reading Light Sensor
29
30  Serial.print("sensor value: ");             //setting  up Serial Monitor to check light sensor value
31  Serial.println(sensorValue);
32
33  currentTime = millis();       //starting time
34  Serial.println(currentTime);
35
36    if (sensorValue<80 && !sittingDown)
37  {
38    sittingDown = true;
39    SitPeriodStart  = currentTime;
40    digitalWrite(A7, LOW);
41  }
42    else if (sensorValue>=80)
43  {
44    sittingDown = false;
45    analogWrite(A7, 1);
46  }
47
48    if  (sittingDown && (currentTime - SitPeriodStart >= sitPeriod))
49  {
50    alarm();
51    alarm();
52    alarm();
53    sittingDown = false;
54  }
55}
56
57void  alarm() {
58    tone(buzzer, NOTE);
59    delay(150);
60    noTone(buzzer);
61    delay(250);
62    tone(buzzer, NOTE);
63    delay(150);
64    noTone(buzzer);
65    delay(250);
66}