[SOLVED] Need Help on designing 4x3 matrix ALPHABETICAL KEYPAD using 8051

MANO.5 · Oct 2, 2014

i want to design a ALPHABETICAL KEYPAD for one of my project that need to store some name on eeprom.When i was searching on web i didn't get anything.The following code is just numerical keypad ,it count and display how many times the key is pressed.I try to alter this code for ALPHABETICAL KEYPAD but i can't.please somebody help to solve this issue.

numerical keypad 4x3

Code C - [expand]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
//LCD Module Connections
sbit rs = P2^0;
sbit rw = P2^1;
sbit en = P2^2;
  #define dataport P1        // Data port for LCD
//End LCD Module Connections
 
//Keypad Connections
sbit R1 = P3^0;
sbit R2 = P3^1;
sbit R3 = P3^2;
sbit R4 = P3^3;
sbit C1 = P3^4;
sbit C2 = P3^5;
sbit C3 = P3^6;
sbit C4 = P3^7;
//End Keypad Connections
 
 
 
     void Delay(unsigned char msdelay)  
{
    unsigned int j;
    unsigned char i;
    for(i=0;i<msdelay;i++)
    for(j=0;j<1275;j++);
}
 
void lcd_command(unsigned char comm)   //LCD command funtion
{
    dataport=comm;
    en=1;
    rs=0;
    rw=0;
    Delay(1);
    en=0;
}
 
void lcd_data(unsigned char disp)  //LCD data function 
{
    dataport=disp;
    en=1;
    rs=1;
    rw=0;
    Delay(1);
    en=0;
}
 
void lcd_ini()                
{
    lcd_command(0x38);      
    Delay(5);
    lcd_command(0x0F);        
        lcd_command(0x0E);      
    Delay(5);
    lcd_command(0x01);        
    Delay(5);
    
}
 
 
lcd_string(unsigned char *disp)  //LCD string function 
{
    char x;
    for(x=0;disp[x]!=0;x++)
    {
        lcd_data(disp[x]);
    }
    
}
 
 
 
char Read_Keypad()
{
 
  C1=1;
  C2=1;
  C3=1;
  C4=1;
  R1=0;
  R2=1;
  R3=1;
  R4=1;
  if(C1==0){Delay(100);while(C1==0);return('1');}
  if(C2==0){Delay(100);while(C2==0);return '2';}
  if(C3==0){Delay(100);while(C3==0);return '3';}
  if(C4==0){Delay(100);while(C4==0);return '4';}
  R1=1;
  R2=0;
  R3=1;
  R4=1;
  if(C1==0){Delay(100);while(C1==0);return '5';}
  if(C2==0){Delay(100);while(C2==0);return '6';}
  if(C3==0){Delay(100);while(C3==0);return '7';}
  if(C4==0){Delay(100);while(C4==0);return '8';}
  R1=1;
  R2=1;
  R3=0;
  R4=1;
  if(C1==0){Delay(100);while(C1==0);return '9';}
  if(C2==0){Delay(100);while(C2==0);return '0';}
  if(C3==0){Delay(100);while(C3==0);return '=';}
  if(C4==0){Delay(100);while(C4==0);return '-';}
  R1=1;
  R2=1;
  R3=1;
  R4=0;
  if(C1==0){Delay(100);while(C1==0);return 'C';}
  if(C2==0){Delay(100);while(C2==0);return '0';}
  if(C3==0){Delay(100);while(C3==0);return '=';}
  if(C4==0){Delay(100);while(C4==0);return '+';}
  return 0;
}
 
void main()
{
   int i=0;
  char c,p;
   lcd_ini();
  while(1)
  {
     lcd_command(0x01);
     lcd_command(0x80);    
       lcd_string("Key  :");
         lcd_command(0xc0);  
        lcd_string("Times:");
    while(!(c = Read_Keypad()));
     
      p=c;
    while(p==c)
    {
      i++;
       lcd_command(0x88);   
     lcd_data(c);
     lcd_command(0xC8);
       lcd_data(i+48);
      Delay(100);
      while(!(c = Read_Keypad()));
    }
    i=0;
   }
}

Venkadesh_M · Oct 2, 2014

What problem you are facing?

betwixt · Oct 2, 2014

Very ambiguous.

I wonder if they are looking for a method of text entry by multiple presses of the same key as on mobile phones. Otherwise it has to be bigger than 4x3.

Brian.

MANO.5 · Oct 6, 2014

Venkadesh_M said:
What problem you are facing?

Hai venkatesh,
thank you for your reply..what i am trying was after getting pressed key value i add one more function set_key(c,i) in set_key function c was key value and i was number of times key pressed .In set key function using switch case key value is displayed.

The modified program was

Code:

#include<reg52.h> //including sfr registers for ports of the controller


//LCD Module Connections
sbit rs = P2^0;
sbit rw = P2^1;
sbit en = P2^2;
  #define dataport P1	     // Data port for LCD
//End LCD Module Connections

//Keypad Connections
sbit R1 = P3^0;
sbit R2 = P3^1;
sbit R3 = P3^2;
sbit R4 = P3^3;
sbit C1 = P3^4;
sbit C2 = P3^5;
sbit C3 = P3^6;
sbit C4 = P3^7;
//End Keypad Connections



	 void Delay(unsigned char msdelay)	
{
	unsigned int j;
	unsigned char i;
	for(i=0;i<msdelay;i++)
	for(j=0;j<1275;j++);
}

void lcd_command(unsigned char comm)   //LCD command funtion
{
	dataport=comm;
	en=1;
	rs=0;
	rw=0;
	Delay(1);
	en=0;
}

void lcd_data(unsigned char disp)  //LCD data function 
{
	dataport=disp;
	en=1;
	rs=1;
	rw=0;
	Delay(1);
	en=0;
}

void lcd_ini()				  
{
	lcd_command(0x38);		
	Delay(5);
	lcd_command(0x0F);        
        lcd_command(0x0E);		
	Delay(5);
	lcd_command(0x01);        
	Delay(5);
	
}


lcd_string(unsigned char *disp)	 //LCD string function 
{
	char x;
	for(x=0;disp[x]!=0;x++)
	{
		lcd_data(disp[x]);
	}
	
}

 void set_key(c,i)
{
switch(c)
{
  case 1:
   {
    switch(i)
    {
     case 1:{
	 lcd_command(0x80);	  
       lcd_data('a');
       Delay(50);       
       break; }

     case 2:{
	 lcd_command(0x80);	  
       lcd_data('b');
       Delay(50);     
       break;       }

     case 3: {
	 lcd_command(0x80);	  
       lcd_data('c');
       Delay(50);       
       break; }
     }
   }
}
}

char Read_Keypad()
{

  C1=1;
  C2=1;
  C3=1;
  C4=1;
  R1=0;
  R2=1;
  R3=1;
  R4=1;
  if(C1==0){Delay(100);while(C1==0);return('1');}
  if(C2==0){Delay(100);while(C2==0);return '2';}
  if(C3==0){Delay(100);while(C3==0);return '3';}
  if(C4==0){Delay(100);while(C4==0);return '4';}
  R1=1;
  R2=0;
  R3=1;
  R4=1;
  if(C1==0){Delay(100);while(C1==0);return '5';}
  if(C2==0){Delay(100);while(C2==0);return '6';}
  if(C3==0){Delay(100);while(C3==0);return '7';}
  if(C4==0){Delay(100);while(C4==0);return '8';}
  R1=1;
  R2=1;
  R3=0;
  R4=1;
  if(C1==0){Delay(100);while(C1==0);return '9';}
  if(C2==0){Delay(100);while(C2==0);return '0';}
  if(C3==0){Delay(100);while(C3==0);return '=';}
  if(C4==0){Delay(100);while(C4==0);return '-';}
  R1=1;
  R2=1;
  R3=1;
  R4=0;
  if(C1==0){Delay(100);while(C1==0);return 'C';}
  if(C2==0){Delay(100);while(C2==0);return '0';}
  if(C3==0){Delay(100);while(C3==0);return '=';}
  if(C4==0){Delay(100);while(C4==0);return '+';}
  return 0;
}

void main()
{
   int i=0;
  char c,p;
   lcd_ini();
  while(1)
  {
    /* lcd_command(0x01);
     lcd_command(0x80);	   
       lcd_string("Key  :");
    	 lcd_command(0xc0);	 
        lcd_string("Times:");	   */
    while(!(c = Read_Keypad()));
	 
	  p=c;
    while(p==c)
    {
      i++;
	  set_key(c,i);
       /*lcd_command(0x88);	
     lcd_data(c);
     lcd_command(0xC8);
       lcd_data(i+48);
      Delay(100);	 */
	  if(i==4)
	  i=0;
      while(!(c = Read_Keypad()));
    }
    i=0;
   }
}

The program compiled without any error .But when simulating in proteus it didn't give anything.

Venkadesh_M · Oct 7, 2014

Its a very easy project don worry. clear your main and check whether your LCD works fine or not ?
After making your LCD work there is nothing in the keyboard side. now lot of mistakes in the code.
So try to display some "hi" in lcd without keypad.
Also post your proteus project and hex file when you come next time.

MANO.5 · Oct 7, 2014

Venkadesh_M said:
Its a very easy project don worry. clear your main and check whether your LCD works fine or not ?
After making your LCD work there is nothing in the keyboard side. now lot of mistakes in the code.
So try to display some "hi" in lcd without keypad.
Also post your proteus project and hex file when you come next time.

Hai venkadesh,
there is no problem with lcd.it works fine.
hex file

Code:

  :1001FF00E4FEEEC39F5011E4FDFC0DBD00010CBCED
:08020F0004F8BDFBF50E80EAC6
:0102170022C4
:100218008F90D2A2C2A0C2A17F011201FFC2A22266
:100228008F90D2A2D2A0C2A17F011201FFC2A22246
:1001DC007F381202187F051201FF7F0F1202187F61
:1001EC000E1202187F051201FF7F011202187F0503
:0301FC000201FFFE
:0601B5008B088A09890A8B
:1001BB00E4F50BAB08AA09A90AAF0BEF3395E08F57
:1001CB0082F583120188FF6007120228050B80E37A
:0101DB002201
:10014C00EE7038EF147034AE04AF05EC702DEF2464
:10015C00FE6010146016240270217F801202187F3A
:10016C006180107F801202187F6280077F801202EC
:0C017C00187F631202287F321201FF225C
:10000300D2B4D2B5D2B6D2B7C2B0D2B1D2B2D2B3D1
:1000130020B40B7F641201FF30B4FD7F312220B581
:100023000B7F641201FF30B5FD7F322220B60B7FB8
:10003300641201FF30B6FD7F332220B70B7F6412B9
:1000430001FF30B7FD7F3422D2B0C2B1D2B2D2B3F6
:1000530020B40B7F641201FF30B4FD7F352220B53D
:100063000B7F641201FF30B5FD7F362220B60B7F74
:10007300641201FF30B6FD7F372220B70B7F641275
:1000830001FF30B7FD7F3822D2B0D2B1C2B2D2B3B2
:1000930020B40B7F641201FF30B4FD7F392220B5F9
:1000A3000B7F641201FF30B5FD7F302220B60B7F3A
:1000B300641201FF30B6FD7F3D2220B70B7F64122F
:1000C30001FF30B7FD7F2D22D2B0D2B1D2B2C2B37D
:1000D30020B40B7F641201FF30B4FD7F432220B5AF
:1000E3000B7F641201FF30B5FD7F302220B60B7FFA
:1000F300641201FF30B6FD7F3D2220B70B7F6412EF
:0B01030001FF30B7FD7F2B227F0022A0
:10010E00E4FBFA1201DC120003A907E960F8890C7E
:10011E00E50C6970240BBB00010AE9FF3395E0FE84
:10012E00AD03AC0212014CEB64044A7002FAFB12EE
:0E013E000003A907EF70D980F6E4FAFB80C831
:03000000020238C1
:0C023800787FE4F6D8FD75810C02010E01
:10018800BB010CE58229F582E5833AF583E022502C
:1001980006E92582F8E622BBFE06E92582F8E22276
:0D01A800E58229F582E5833AF583E4932290
:00000001FF

i can't upload proteus design ,the ploader says it was invalid file...........

Venkadesh_M · Oct 8, 2014

Try this code, compress and post the project files.

Code C - [expand]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
#include<reg52.h> //including sfr registers for ports of the controller
 
//LCD Module Connections
sbit rs = P2^0;
sbit rw = P2^1;
sbit en = P2^2;
  #define dataport P1        // Data port for LCD
//End LCD Module Connections
 
//Keypad Connections
sbit R1 = P3^0;
sbit R2 = P3^1;
sbit R3 = P3^2;
sbit R4 = P3^3;
sbit C1 = P3^4;
sbit C2 = P3^5;
sbit C3 = P3^6;
sbit C4 = P3^7;
//End Keypad Connections
 
 
void Delay(unsigned char);  
void lcd_command(unsigned char);   //LCD command funtion
void lcd_data(unsigned char);  //LCD data function 
void lcd_ini(void);               
void lcd_string(unsigned char *);    //LCD string function 
void set_key(unsigned int,unsigned int,unsigned int);
char Read_Keypad(void);
 
void main()
{
   unsigned int c = 0, p = 0, pos = 0, i = 0;
 
   lcd_ini();
   
  while(1)
  {
    p = c;
    
    while(!(c = Read_Keypad())); 
    
    if(p == c)
    {
      set_key(c,i,pos);
      
      if(++i >= 3)
      i=0;
    }
    else
    {
    i = 0;
    pos++;
    }
 
   }
}
 
void set_key(unsigned int c,unsigned int i, unsigned int pos)
{
    lcd_command(0x80 + pos);      
    lcd_data('a' + c*3 + i );
    Delay(50);       
}
 
void Delay(unsigned char msdelay)   
{
    unsigned int j;
    unsigned char i;
    for(i=0;i<msdelay;i++)
    for(j=0;j<1275;j++);
}
 
void lcd_command(unsigned char comm)   //LCD command funtion
{
    dataport=comm;
    en=1;
    rs=0;
    rw=0;
    Delay(1);
    en=0;
}
 
void lcd_data(unsigned char disp)  //LCD data function 
{
    dataport=disp;
    en=1;
    rs=1;
    rw=0;
    Delay(1);
    en=0;
}
 
void lcd_ini()                
{
    lcd_command(0x38);      
    Delay(5);
    lcd_command(0x0F);        
        lcd_command(0x0E);      
    Delay(5);
    lcd_command(0x01);        
    Delay(5);
    
}
 
 
void lcd_string(unsigned char *disp)     //LCD string function 
{
    char x;
    for(x=0;disp[x]!=0;x++)
    {
        lcd_data(disp[x]);
    }
    
}
 
 
char Read_Keypad(void)
{
 
  C1 = 1;  C2 = 1;  C3 = 1;  C4 = 1;
  R1 = 0;  R2 = 0;  R3 = 0;  R4 = 0;
  if( C1 && C2 && C3 && C4 )
  return 0;
  
  R1=0;
  R2=1;
  R3=1;
  R4=1; 
  if(C1==0){Delay(100);while(C1==0);return 1;}
  if(C2==0){Delay(100);while(C2==0);return 2;}
  if(C3==0){Delay(100);while(C3==0);return 3;}
  if(C4==0){Delay(100);while(C4==0);return 4;}
  R1=1;
  R2=0;
  R3=1;
  R4=1;
  if(C1==0){Delay(100);while(C1==0);return 5;}
  if(C2==0){Delay(100);while(C2==0);return 6;}
  if(C3==0){Delay(100);while(C3==0);return 7;}
  if(C4==0){Delay(100);while(C4==0);return 8;}
  R1=1;
  R2=1;
  R3=0;
  R4=1;
  if(C1==0){Delay(100);while(C1==0);return 9;}
  if(C2==0){Delay(100);while(C2==0);return 10;}
  if(C3==0){Delay(100);while(C3==0);return 11;}
  if(C4==0){Delay(100);while(C4==0);return 12;}
  R1=1;
  R2=1;
  R3=1;
  R4=0;
  if(C1==0){Delay(100);while(C1==0);return 13;}
  if(C2==0){Delay(100);while(C2==0);return 14;}
  if(C3==0){Delay(100);while(C3==0);return 15;}
  if(C4==0){Delay(100);while(C4==0);return 16;}
  return 0;
}

MANO.5 · Oct 10, 2014

Hai Venkadesh,
Thank you so much.Your code is working.I modify the code by adding EEPROM and forward,backspace key .I upload the protes design,HEX code. back space key is not working properly. please help to solve this problem also....

Venkadesh_M · Oct 10, 2014

Hi

in while make these change

Remember you cant press the same key consecutively in old code for that you need a timing mechanism.

I added timer in following code

Code C - [expand]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
while(1)
  {
    p = c;    
 
    time = 5000000;
 
    while(!(c = Read_Keypad()) &&  time--); 
 
    if (time == 0)
    pos++;
    
    if(p == c && c != 14)
    {
     set_key(c,i,pos);
      
      if(++i >= 3)
      i=0;
    }
    else if(c == 14)
    {
    pos--;
    set_key(c,i,pos);
    i = 0;
    }
    else
    {
    i = 0;
    pos++;
    }
}

declare time as unsigned long

you can change the value for going to next char

Venkadesh_M · Oct 10, 2014

Small change

Code C - [expand]
1
2
3
4
5
6
else if(c == 14)
    {
    set_key(c,i,pos);
    pos--;
    i = 0;
    }

MANO.5 · Oct 15, 2014

Venkadesh_M said:

Hai Venkatesh,
Thank you for your help.it was working now.........................

MANO.5 · Oct 16, 2014

Hai venkatesh,
There is small problem can't type like 'baby'.need something time counter .If same key is pressed within 10 seconds and if not increase pos value .Please some help............

Venkadesh_M · Oct 17, 2014

reduce the value of time variable in #9. post the hex file, i can also have a try.

MANO.5 · Oct 17, 2014

Venkadesh_M said:
reduce the value of time variable in #9. post the hex file, i can also have a try.

Hai
reduce the time value [time=5000000]; to [time=2];But no change.This is the hex file

Code:

:0F04DA00D2A3E4FFD2A4C2A40FEFC3940A40F54B
:0104E90022F0
:09051600D2A3D2A4C2A3C2A42204
:09051F00C2A4C2A3D2A4D2A322FB
:1003EF00AB07AA06C2D71205167FA0120404AF02EC
:0503FF00120404AF032D
:10040400E4FEFDEEC313FE70027E80EE5F6004D254
:10041400D78002C2D792A3D2A4C2A40DBD08E4D24D
:07042400A3D2A4A2A3C2A40D
:01042B0022AE
:10045300E4FFD2A3FEC2D7EF25E0FFD2A4A2A3C23A
:10046300A430D7010F0EC3EE6480948840E7D2A373
:04047300D2A4C2A4A9
:010477002262
:0404B4008C1E8D1FEE
:1004B8001203EFAF1F12040412051F7F0D02049BE5
:1004C8001203EF1205167FA1120404120453120539
:0104D8001F04
:0104D9002200
:10000300E4F508F509F50AF50B74FFF50CF50DE4B5
:10001300F50EF50FF510F511751502F514F513F539
:10002300121204781204DA85080A85090B12016694
:10003300EF3395E0F5088F094F700D781274FF12B6
:1000430003D1EC4D4E4F70E5E50B65097004E50AED
:100053006508704DE509640E45086045E509640FC0
:100063004508603DD3E50D940FE50C9400E50D4084
:100073001024F0F511E50C34FFF510E51124C080D0
:10008300022480FF1204EA120288050FE50F7002B2
:10009300050EC39403E50E940050030201450201CB
:1000A30010E509640E45087030E50D150D70021555
:1000B3000CD3E50D940FE50C9400E50D401024F0EE
:1000C300F511E50C34FFF510E51124C080022480FE
:1000D300FF1204EA1202888034E509640F450870B0
:1000E30033050DE50D7002050CD3940FE50C940058
:1000F300E50D401024F0F511E50C34FFF510E51182
:1001030024C080022480FF1204EA120288E4F50E60
:10011300F50F802EE4F50EF50F050DE50D700205C4
:100123000CD3940FE50C9400E50D401024F0F51169
:10013300E50C34FFF510E51124C080022480FF1282
:1001430004EAE4FFFEFDFCAB15AA14A913A812C32D
:100153001203BE600302002A050DE50D7002050CB3
:0301630002002A6D
:0C028800AB0DAA0CAD0FAC0EAF09AE0818
:0C0294008E168F178C188D198A1A8B1B80
:1002A000E4F51CF51DD3E5179409E51694004017F5
:1002B000E517940DE5169400500D7C007D031203A4
:1002C000ACEF2412020358E517640D4516702BE5B8
:1002D0001945187007F51C751D398068E51964010A
:1002E00045187007F51C751D2E8059E519640245E7
:1002F000187051F51C751D2D804AE517640E4516C2
:1003000070028008E517640F45167007F51C751D0F
:10031000208031E51764104516702FE519451870D7
:1003200007F51C751D2D801CE51964014518700723
:10033000F51C751D3D800DE519640245187005F525
:100340001C751D23AD1DAC1C801FAE16AF177C00A5
:100350007D031203ACEF243EFFE43EFEE5192FF5CA
:100360001DE5183EF51CAD1DFCAF1BAE1A1204B402
:0F037000AF1BAE1A1204C81204FA7F0A02049BD4
:10049B00E4FEEEC39F5011E4FDFC0DBD00010CBC4E
:0804AB0004F8BDFBF50E80EA28
:0104B3002226
:1004EA008F90D2A2C2A0C2A17F0112049BC2A222F3
:1004FA008F90D2A2D2A0C2A17F0112049BC2A222D3
:100478007F381204EA7F0512049B7F0F1204EA7F7B
:100488000E1204EA7F0512049B7F011204EA7F051D
:0304980002049BC0
:06042C008B208A218922C9
:10043200E4F523AB20AA21A922AF23EF3395E08F65
:1004420082F58312037FFF60071204FA052380E31B
:010452002287
:10016600D2B4D2B5D2B6D2B7C2B0C2B1C2B2C2B39D
:1001760030B40C30B50930B60630B7037F0022C262
:10018600B0D2B1D2B2D2B320B40B7F0A12049B30E4
:10019600B4FD7F012220B50B7F0A12049B30B5FD0A
:1001A6007F022220B60B7F0A12049B30B6FD7F0326
:1001B6002220B70B7F0A12049B30B7FD7F0422D2A0
:1001C600B0C2B1D2B2D2B320B40B7F0A12049B30B4
:1001D600B4FD7F052220B50B7F0A12049B30B5FDC6
:1001E6007F062220B60B7F0A12049B30B6FD7F07DE
:1001F6002220B70B7F0A12049B30B7FD7F0822D25C
:10020600B0D2B1C2B2D2B320B40B7F0A12049B3073
:10021600B4FD7F092220B50B7F0A12049B30B5FD81
:100226007F0A2220B60B7F0A12049B30B6FD7F0B95
:100236002220B70B7F0A12049B30B7FD7F0C22D217
:10024600B0D2B1D2B2C2B320B40B7F0A12049B3033
:10025600B4FD7F0D2220B50B7F0A12049B30B5FD3D
:100266007F0E2220B60B7F0A12049B30B6FD7F0F4D
:100276002220B70B7F0A12049B30B7FD7F10227F26
:02028600002254
:0300000002050AEC
:0C050A00787FE4F6D8FD75812302000321
:10037F00BB010CE58229F582E5833AF583E0225033
:10038F0006E92582F8E622BBFE06E92582F8E2227D
:0D039F00E58229F582E5833AF583E4932297
:1003AC00EF8DF0A4A8F0CF8CF0A428CE8DF0A42E65
:0203BC00FE221F
:1003BE00EB9FF5F0EA9E42F0E99D42F0E89C45F095
:0103CE00220C
:1003CF007401FF3395E0FEFDFC080808E6CF2FF619
:1003DF0018E6CE3EF618E6CD3DF618E6CC3CF622F2
:00000001FF

Venkadesh_M · Oct 17, 2014

Hi make change,
instead of this

Code C - [expand]
1
while(!(c = Read_Keypad()) &&  time--);

code this

Code C - [expand]
1
while( ( !(c = Read_Keypad()) ) &&  time--);

and now try editing the time value..

MANO.5 · Oct 17, 2014

Hai,
No change in output.............

Venkadesh_M · Oct 17, 2014

the initialization of the time variable should be inside while loop like in #9.

MANO.5 · Oct 17, 2014

Hai.
this code is working

Code:

while(1)
  {
 
   p = c;   
   time=15000;
    //while(!(c = Read_Keypad()) &&  time--); 		 	 
    while( ( !(c = Read_Keypad()) ) &&  time--);
	if (time == 0)	
	 pos++;	
    if(p == c && c != 14 && c != 15)
    {
	  	if(pos>15)
		{
		j=pos-16;
		 
		 lcd_command(0xC0+j);  
		}
		else
		{
	 	lcd_command(0x80+pos); 
		}
        set_key(c,i,pos);
		  if(++i >= 3)
        i=0; 
    }
    else if(c == 14)
    {
    pos--;
	if(pos>15)
		{
		 j=pos-16;
		 lcd_command(0xC0+j);  
		}
		else
		{
	 	lcd_command(0x80+pos); 
		}
    set_key(c,i,pos);
    i = 0;
    }
	else if(c == 15)
    {
    pos++;
	if(pos>15)
		{
		 j=pos-16;
		 lcd_command(0xC0+j);  
		}
		else
		{
	 	lcd_command(0x80+pos); 
		}
    set_key(c,i,pos);
    i = 0;
    }
    else
    {
    i = 0;
    pos++;
	if(pos>15)
		{
		 j=pos-16;
		 lcd_command(0xC0+j);  
		}
		else
		{
	 	lcd_command(0x80+pos); 
		}
    }
	}

but if we need to type "baby" the output is "b a by". BECAUSE pos value is incremented 2 times ... In first at //if (time == 0)
pos++ and second is

Code:

 else
    {
    i = 0;
    pos++;
	if(pos>15)
		{
		 j=pos-16;
		 lcd_command(0xC0+j);  
		}
		else
		{
	 	lcd_command(0x80+pos); 
		}
    }

Venkadesh_M · Oct 18, 2014

Then just remove the

Code C - [expand]
1
2
if(time == 0)
pos++;

MANO.5 · Oct 18, 2014

Hi,
No change in output. it will show like "b a b y" and if time=0 before pressing any other key it will show some random values.... This is the proteus design and hex file....

Welcome to EDAboard.com

[SOLVED] Need Help on designing 4x3 matrix ALPHABETICAL KEYPAD using 8051

Member level 1

Advanced Member level 4

Super Moderator

Member level 1

Advanced Member level 4

Member level 1

Advanced Member level 4

Member level 1

Attachments

Advanced Member level 4

Advanced Member level 4

Member level 1

Attachments

Member level 1

Advanced Member level 4

Member level 1

Advanced Member level 4

Member level 1

Advanced Member level 4

Member level 1

Advanced Member level 4

Member level 1

Attachments

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor