Easy Countdown with Buzzer

1/*Countdown with buzzer*/
2
3#define button 10     //button Pin
4#define   buz 11        //buzzer Pin
5#define pin_tens 13   //tens   Pin, this pin control   the tens
6#define pin_unit 12   //unit   Pin, this pin control the unit
7#define   start 9       //start  Pin
8#define reset A0      //reset Pin
9
10//Variables
11int   timee = 0;
12int unit = 0, tens = 0;
13unsigned long time_countdown = 0;
14
15//display   segment
16int a = 2; //pin 7 of the display 
17int b = 3; //pin 6
18int c = 4;   //pin 4
19int d = 5; //pin 2
20int e = 6; //pin 1
21int f = 7; //pin 9
22int   g = 8; //pin 10
23
24void setup() {
25  pinMode(button, INPUT);
26  pinMode(reset,   INPUT);
27  pinMode(start, INPUT);
28  pinMode(buz, OUTPUT);
29  pinMode(a, OUTPUT);
30   pinMode(b, OUTPUT);
31  pinMode(c, OUTPUT);
32  pinMode(d, OUTPUT);
33  pinMode(e,   OUTPUT);
34  pinMode(f, OUTPUT);
35  pinMode(g, OUTPUT);
36}
37
38//This function   display the number with a combination of segments for each number 
39void print_number(int   n) {
40  switch (n) {
41    case 0: //number zero
42      digitalWrite(a, HIGH);
43       digitalWrite(b, HIGH);
44      digitalWrite(c, HIGH);
45      digitalWrite(d,   HIGH);
46      digitalWrite(e, HIGH);
47      digitalWrite(f, HIGH);
48      digitalWrite(g,   LOW);
49      break;
50    case 1: //number one
51      digitalWrite(a, LOW);
52       digitalWrite(b, HIGH);
53      digitalWrite(c, HIGH);
54      digitalWrite(d,   LOW);
55      digitalWrite(e, LOW);
56      digitalWrite(f, LOW);
57      digitalWrite(g,   LOW);
58      break;
59    case 2: //number two
60      digitalWrite(a, HIGH);
61       digitalWrite(b, HIGH);
62      digitalWrite(c, LOW);
63      digitalWrite(d,   HIGH);
64      digitalWrite(e, HIGH);
65      digitalWrite(f, LOW);
66      digitalWrite(g,   HIGH);
67      break;
68    case 3: //number three
69      digitalWrite(a, HIGH);
70       digitalWrite(b, HIGH);
71      digitalWrite(c, HIGH);
72      digitalWrite(d,   HIGH);
73      digitalWrite(e, LOW);
74      digitalWrite(f, LOW);
75      digitalWrite(g,   HIGH);
76      break;
77    case 4: //number four
78      digitalWrite(a, LOW);
79       digitalWrite(b, HIGH);
80      digitalWrite(c, HIGH);
81      digitalWrite(d,   LOW);
82      digitalWrite(e, LOW);
83      digitalWrite(f, HIGH);
84      digitalWrite(g,   HIGH);
85      break;
86    case 5: //number five
87      digitalWrite(a, HIGH);
88       digitalWrite(b, LOW);
89      digitalWrite(c, HIGH);
90      digitalWrite(d,   HIGH);
91      digitalWrite(e, LOW);
92      digitalWrite(f, HIGH);
93      digitalWrite(g,   HIGH);
94      break;
95    case 6: //number six
96      digitalWrite(a, HIGH);
97       digitalWrite(b, LOW);
98      digitalWrite(c, HIGH);
99      digitalWrite(d,   HIGH);
100      digitalWrite(e, HIGH);
101      digitalWrite(f, HIGH);
102      digitalWrite(g,   HIGH);
103      break;
104    case 7: //number seven
105      digitalWrite(a, HIGH);
106       digitalWrite(b, HIGH);
107      digitalWrite(c, HIGH);
108      digitalWrite(d,   LOW);
109      digitalWrite(e, LOW);
110      digitalWrite(f, LOW);
111      digitalWrite(g,   LOW);
112      break;
113    case 8: //number eight
114      digitalWrite(a, HIGH);
115       digitalWrite(b, HIGH);
116      digitalWrite(c, HIGH);
117      digitalWrite(d,   HIGH);
118      digitalWrite(e, HIGH);
119      digitalWrite(f, HIGH);
120      digitalWrite(g,   HIGH);
121      break;
122    case 9: //number nine
123      digitalWrite(a, HIGH);
124       digitalWrite(b, HIGH);
125      digitalWrite(c, HIGH);
126      digitalWrite(d,   LOW);
127      digitalWrite(e, LOW);
128      digitalWrite(f, HIGH);
129      digitalWrite(g,   HIGH);
130      break;
131  }
132}
133
134void loop() {
135  if(digitalRead(reset)   == LOW){ //If you push the zero button, you reset the time
136    delay(10);
137     timee = 0;
138  }
139  if (digitalRead(button) == LOW) { //If you push the first   botton the time rises up
140    timee = timee + 1;
141    if (timee == 100) timee   = 0;    //time max = 99, if time == 100 -> time becomes 0
142    delay(150);
143   }
144  //separation between unit and tens
145  tens = timee / 10;
146  unit =   timee - (tens * 10);
147  
148  digitalWrite(pin_tens, HIGH); //active the tens   display 
149  digitalWrite(pin_unit, LOW); //disable the unit display
150  if (tens   != 0) {  //If tenses are == zero the tenses'display stay off
151    print_number(tens);    //Display the tens
152  }
153  else digitalWrite(pin_tens, LOW); 
154  delay(1);
155   digitalWrite(pin_tens, LOW);
156  digitalWrite(pin_unit, LOW);
157  delay(2);
158   digitalWrite(pin_tens, LOW);
159  digitalWrite(pin_unit, HIGH);
160  print_number(unit);      //Display the unit
161  delay(1);
162  digitalWrite(pin_tens, LOW);
163  digitalWrite(pin_unit,   LOW);
164  delay(2);
165
166  if (digitalRead(start) == LOW) { //If the start button   is pressed the time go down
167    time_countdown = millis(); 
168    while (timee   > 0) {
169      tens = timee / 10;
170      unit = timee - (tens * 10);
171      digitalWrite(pin_tens,   HIGH);
172      digitalWrite(pin_unit, LOW);
173      if (tens != 0) { 
174        print_number(tens);    //Display the tens
175      }
176      else digitalWrite(pin_tens, LOW);
177       delay(1);
178      digitalWrite(pin_tens, LOW);
179      digitalWrite(pin_unit,   LOW);
180      delay(2);
181      digitalWrite(pin_tens, LOW);
182      digitalWrite(pin_unit,   HIGH);
183      print_number(unit);   //Display the unit
184      delay(1);
185       digitalWrite(pin_tens, LOW);
186      digitalWrite(pin_unit, LOW);
187      delay(2);
188       if (millis() - time_countdown >= 998) { //The while loop ends when 'timee'   become zero
189        timee = timee - 1;
190        time_countdown = millis();
191       }
192      if (timee == 0) { //if time arrive to zero the buzzer play and   display zero
193        int i;
194        digitalWrite(a, HIGH);
195        digitalWrite(b,   HIGH);
196        digitalWrite(c, HIGH);
197        digitalWrite(d, HIGH);
198        digitalWrite(e,   HIGH);
199        digitalWrite(f, HIGH);
200        digitalWrite(g, LOW);
201        digitalWrite(pin_unit,   HIGH);
202        for (i = 0; i < 10; i++) {
203          analogWrite(buz, 240);
204           delay(100);
205          digitalWrite(buz, LOW);
206          delay(100);
207         }
208        digitalWrite(a, LOW);
209        digitalWrite(b, LOW);
210         digitalWrite(c, LOW);
211        digitalWrite(d, LOW);
212        digitalWrite(e,   LOW);
213        digitalWrite(f, LOW);
214        digitalWrite(g, LOW);
215      }
216     }
217
218  }
219}
220