├── keypad without library.png
└── keypad without library.txt


/keypad without library.png:
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https://raw.githubusercontent.com/vishalgopal2004/keypad-without-library/4d7ab8580f7237e2b3cc8f81cb91862e13c3fae3/keypad without library.png


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/keypad without library.txt:
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  1 | int c1 = 7, c2 = 6, c3 = 5, c4 = 4;
  2 | int r1 = 13, r2 = 12,r3 = 11, r4 = 10; 
  3 | void setup(){
  4 |   pinMode(c1, INPUT_PULLUP);
  5 |    pinMode(c2, INPUT_PULLUP);
  6 |    pinMode(c3, INPUT_PULLUP);
  7 |    pinMode(c4, INPUT_PULLUP);
  8 |    
  9 |   pinMode(r1, OUTPUT);
 10 |    pinMode(r2, OUTPUT);
 11 |   pinMode(r3, OUTPUT);
 12 |    pinMode(r4, OUTPUT);
 13 |   
 14 |   digitalWrite(r1, HIGH);
 15 |   digitalWrite(r2, HIGH);
 16 |   digitalWrite(r3, HIGH);
 17 |   digitalWrite(r4, HIGH);
 18 |   
 19 |   Serial.begin(38400);
 20 | }
 21 | 
 22 | void loop()
 23 | {
 24 |   row1();
 25 |   row2();
 26 |   row3();
 27 |   row4();
 28 |   //Serial.println(" Press any Key to see the value:");
 29 | }
 30 | 
 31 | void row1()
 32 | {
 33 |   digitalWrite(r1, LOW);
 34 |   digitalWrite(r2, HIGH);
 35 |   digitalWrite(r3, HIGH);
 36 |   digitalWrite(r4, HIGH);
 37 |   if(digitalRead(c1)== LOW){//pin 5
 38 |     Serial.println("1");
 39 |     delay(600);}
 40 |   else if(digitalRead(c2)== LOW){//pin 4
 41 |     Serial.println("2");
 42 |     delay(600);}
 43 |    else if(digitalRead(c3)== LOW){//pin 3
 44 |     Serial.println("3");
 45 |     delay(600);}
 46 |    else if(digitalRead(c4)== LOW){
 47 |     Serial.println("A");//pin 2
 48 |  
 49 |     delay(600);}
 50 | }
 51 | void row2(){
 52 |   digitalWrite(r1, HIGH);
 53 |   digitalWrite(r2, LOW);
 54 |   digitalWrite(r3, HIGH);
 55 |   digitalWrite(r4, HIGH);
 56 |   if(digitalRead(c1) == LOW) {
 57 |     Serial.println("4");
 58 |     delay(600);}
 59 |   else if(digitalRead(c2) == LOW) {
 60 |     Serial.println("5");
 61 |     delay(600); }
 62 |   else if(digitalRead(c3) == LOW) {
 63 |     Serial.println("6");
 64 |     delay(600);
 65 |   }
 66 |   else if(digitalRead(c4) == LOW) {
 67 |     Serial.println("B");
 68 |     delay(600);
 69 |   }
 70 | }
 71 |   
 72 | void row3(){
 73 |   digitalWrite(r1, HIGH);
 74 |   digitalWrite(r2, HIGH);
 75 |   digitalWrite(r3, LOW);
 76 |   digitalWrite(r4, HIGH);
 77 |   
 78 |   if(digitalRead(c1) == LOW){
 79 |     Serial.println("7");
 80 |     delay(600);}
 81 |   else if(digitalRead(c2) == LOW) {
 82 |     Serial.println("8");
 83 |     delay(600);}
 84 |   else if(digitalRead(c3) == LOW) {
 85 |     Serial.println("9");
 86 |     
 87 |     delay(600);}
 88 |   else if(digitalRead(c4) == LOW) {
 89 |     Serial.println("C");
 90 |     delay(600);}
 91 | }
 92 | void row4(){
 93 |   digitalWrite(r1, HIGH);
 94 |   digitalWrite(r2, HIGH);
 95 |   digitalWrite(r3, HIGH);
 96 |   digitalWrite(r4, LOW);
 97 |   if(digitalRead(c1) == LOW){
 98 |     Serial.println("*");
 99 |     delay(600);}
100 |   else if(digitalRead(c2) == LOW) {
101 |     Serial.println("0");
102 |       delay(600); }
103 |   else if(digitalRead(c3) == LOW) {
104 |     Serial.println("#");
105 |     delay(600); }
106 |   else if(digitalRead(c4) == LOW) {
107 |     Serial.println("D");
108 |   delay(600);}
109 | }


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