Tilt switch alarm

1
2// Tilt switch alarm using Arduino UNO and shield November 2021
3
4/*
5  * Connections: 
6 * 
7 * 5 Volt Red LED Anode to d8 Cathode to Ground
8 *  
9 * 5 Volt Yellow LED Anode to d9 Cathode to Ground
10 * 
11 * Tilt switch  1 - 2* contacts to d10 2* contacts to Ground
12 * 
13 * Tilt switch 2 - 2* contacts  to d10 2* contacts to Ground
14 * 
15 * Piezo element 1* contact to d3 other contact  to Ground
16 * 
17 * Source for timer interrupt calculations:
18 * 
19 * AVR  Timer CTC Interrupts Calculator
20 * v. 8
21 * http://www.arduinoslovakia.eu/application/timer-calculator
22  * Microcontroller: ATmega328P
23 * Created: 2021-12-14T01:44:28.542Z
24 *
25*/
26
27#define  button_1 10
28#define button_2 11
29
30#define yellow_led 9
31#define red_led  8
32#define piezo_sounder 3 
33
34#define my_test // test mode shortens piezo_sounder  time
35             
36const int number_of_buttons =2;
37
38//piezo_sounder  time in milliseconds
39#ifdef my_test
40const unsigned long the_alarm_time=500;
41#else
42const  unsigned long the_alarm_time=10000;
43#endif
44
45const int piezo_sounder_frequency  =4000;//set at resonant frequency of piezo sounder for maximum volume
46
47//required  to debounce switch
48#define MAX_CHECKS 10
49
50uint8_t State[MAX_CHECKS]={0};
51uint8_t  Index=0;
52
53volatile bool sensor_changed=false;//accessed by isr and main loop  code
54
55
56// the setup function runs once when you press reset or power the  board
57void setup() {
58
59//for switches
60  pinMode(button_1,INPUT_PULLUP);
61  pinMode(button_2,INPUT_PULLUP);
62
63//for leds
64  pinMode(yellow_led,OUTPUT);
65  pinMode(red_led,OUTPUT);
66  pinMode(piezo_sounder,OUTPUT);
67
68// initialize  timer1
69
70  setupTimer1();
71  
72}
73
74// the loop function runs over  and over again forever
75void loop() {
76
77int count=0;
78
79//alarm set delay
80//flash  yellow led 4 times then red led once
81// 0 1  2 3  4  5 6  7 8 9
82//[y][][y][][y][][y][][r][]  Exit loop
83  do
84{
85
86
87    switch(count)
88    {
89      case 1:digitalWrite(yellow_led,HIGH);break;
90      case 2:digitalWrite(yellow_led,LOW);break;
91      case 3:digitalWrite(yellow_led,HIGH);break;
92      case 4:digitalWrite(yellow_led,LOW);break;
93      case 5:digitalWrite(yellow_led,HIGH);break;
94      case 6:digitalWrite(yellow_led,LOW);break;
95      case 7:digitalWrite(yellow_led,HIGH);break;
96      case 8:digitalWrite(yellow_led,LOW);break;
97      
98      case 9:digitalWrite(red_led,1);break;
99      }
100
101      delay(1000);
102    
103      count++;
104    
105      if(sensor_changed){count=0;sensor_changed=false;digitalWrite(red_led,LOW);}
106    
107} while (count<10);
108
109digitalWrite(red_led,LOW);
110
111
112//wait  for sensor change trigger
113while(!sensor_changed){}
114sensor_changed=false;
115
116//countdown  to allow alarm to be disabled
117count=0;
118  do
119{
120    // statement block
121    digitalWrite(red_led, digitalRead(red_led) ^ 1);   // toggle LED pin
122    delay(1000);
123    count++;
124} while (count<9);
125    digitalWrite(red_led, digitalRead(red_led)  ^ 1);   // toggle LED pin
126
127//sound alarm once for the_alarm_time
128
129bool  alarm_done=false;
130
131do{
132  if(!alarm_done){//sound alarm first time through
133
134    alarm_done=true;
135    tone(piezo_sounder, piezo_sounder_frequency ,the_alarm_time);//  pin, frequency, duration
136    
137  }
138  else {//subsequently light led to alert  user that alarm has been tripped
139
140    digitalWrite(red_led,HIGH);   // turn  on red_led
141    delay(5000);
142    digitalWrite(red_led,LOW);   // turn off red_led
143
144  }
145  
146
147//wait for sensor change trigger
148sensor_changed=false; 
149while(!sensor_changed){}
150sensor_changed=false;
151
152}while(1);//infinite  loop
153
154
155}
156
157//My_functions
158
159void setupTimer1() {
160  noInterrupts();
161  // Clear registers
162  TCCR1A = 0;
163  TCCR1B = 0;
164  TCNT1 = 0;
165
166  //  100 Hz (16000000/((624+1)*256))
167  OCR1A = 624;
168  // CTC
169  TCCR1B |= (1  << WGM12);
170  // Prescaler 256
171  TCCR1B |= (1 << CS12);
172  // Output Compare  Match A Interrupt Enable
173  TIMSK1 |= (1 << OCIE1A);
174  interrupts();
175}
176
177ISR(TIMER1_COMPA_vect)  // timer compare interrupt service routine
178{
179
180//read buttons
181  uint8_t  temp=0x00;
182  temp|=!digitalRead(button_1)<<0;
183  temp|=!digitalRead(button_2)<<1;
184          
185//debounce
186static uint8_t Debounced_State=0;
187static uint8_t  Previous_Debounced_State=0;
188Previous_Debounced_State=Debounced_State;
189   
190  uint8_t i,j;
191  State[Index]= temp;
192  ++Index;
193  j=0xFF;
194  for (i=0;i<MAX_CHECKS;i++){j=j&State[i];}
195  Debounced_State=j;
196  if(Index>=MAX_CHECKS){Index=0;} 
197
198  if (Debounced_State!=Previous_Debounced_State){sensor_changed=true;}
199    
200}
201//-----------end------------  
202