4*8 key matrix - need correction of diagram, module

4*8 key matrix help

have any tell me can i make 8*4 key matrix

#ifndef KBOARD_H
#define KBOARD_H

#include "reg51.h"
#include "Delay.h"
//#include "Lcd.h"
#include <intrins.h>
#include<stdio.h>

/*****************************************************************************
*
* Constant Definitions.
*
*****************************************************************************/

/**
* Hardware keyboard port assignment.
* Adjust \b KEYPORT to match hardware.
* \hideinitializer
*/
#define KEYPORT P0

/*
* idkey() return this when no key is pressed.
*/
#define NOKEY 32


/*****************************************************************************
*
* Public Function Prototypes.
*
*****************************************************************************/

//extern char _getkey(void); // defined in stdio.h

/**
* 4 x 8 keyboard initialisation function.
* \param -
* \return -
*/
extern void kboard_init(void);

#endif
******************************************************************************/

#include "Kboard.h"

/*****************************************************************************
*
* Global Variables
*
*****************************************************************************/
/*
* Keyboard scan row/ column output and input pattern codes.
*/
static const unsigned char code KEY_IO[32] = {0x70, 0xB0, 0xD0, 0xE0,
0x71, 0xB1, 0xD1, 0xE1,
0x72, 0xB2, 0xD2, 0xE2,
0x73, 0xB3, 0xD3, 0xE3,
0x74, 0xB4, 0xD4, 0XE4,
0x75, 0xB5, 0xD5, 0xE5,
0x76, 0xB6, 0xD6, 0xE6,
0x77, 0xB7, 0xD7, 0xE7};

/*
* Keyboard key position to ASCII representation codes.
*/
static const char code KEY_MAP[32] = {'1', '2', '3', '4',
'5', '6', '7', '8',
'9', 'A','B','C',
'D','E','F','G',
'H','I','J','K',
'L','M','N','O',
'P','Q','R','S',
'T','U','V','W' }; // CR BS

/*****************************************************************************
*
* Private Function Prototypes
*
*****************************************************************************/
static unsigned char kboard_makekey(void);
static void kboard_breakkey(void);
static unsigned char kboard_idkey(void);


/*****************************************************************************
*
* Private Function Implementation
*
*****************************************************************************/

/*****************************************************************************
*
* kboard_makekey()
*
*****************************************************************************/
static unsigned char kboard_makekey(void)
{
unsigned char key, newkey;

do
{
while((key = kboard_idkey()) == NOKEY);
#ifdef LCD_H
lcd_beep(5);
#endif
delay_ms(10);
} while((newkey = kboard_idkey()) != key);

return(key);
}

/*****************************************************************************
*
* kboard_breakkey()
*
*****************************************************************************/
static void kboard_breakkey(void)
{
do
{
while(kboard_idkey() != NOKEY);
delay_ms(10);
} while(kboard_idkey() != NOKEY);
}

/*****************************************************************************
*
* kboard_idkey()
*
*****************************************************************************/
static unsigned char kboard_idkey(void)
{
unsigned char key = 0xFF;
bit keyfound = 0;

do
{
key++;
KEYPORT &= 0xF0; // clear lower nibble
KEYPORT |= KEY_IO[key] & 0x0F; // output lower nibble
keyfound = ((KEYPORT & 0xF0) == (KEY_IO[key] & 0xF0));

} while((key < NOKEY) && (!keyfound));

return(key);
}


/*****************************************************************************
*
* Public Function Implementation
*
*****************************************************************************/

/*****************************************************************************
*
* kboard_init()
*
*****************************************************************************/
void kboard_init(void)
{
KEYPORT = 0xFF; // Set all bits as input
}

/*****************************************************************************
*
* _getkey()
*
*****************************************************************************/
char _getkey(void)
{
unsigned char key = NOKEY;

while(key == NOKEY)
{
key = kboard_makekey();
kboard_breakkey();
}

return (KEY_MAP[key]);
}
********************************************************************
********************************************************************
MAIN.C
****************************************************************************************************************************************
#include<reg51.h>
#include<stdio.h>
#include "Kboard.h"

void main()
{
unsigned int ch=0;
kboard_init();
while(1)
{
scanf("%d",&ch);
}
}

Re: 4*8 key matrix help

What is the question here ?

Did you make the circuit and is not working ?

What do you need to know ?

Re: 4*8 key matrix help

i request please cheak this code and diagram is this work if not please correct this module and diagram
thanks for reply

Re: 4*8 key matrix help

HI

Add some pullup resistor for P0.4~P0.7

All the best

Bobi

Re: 4*8 key matrix help

hello sir,
this is not work when i press any key P0^0 goes 1 and P0^0-P0^4 goes 1 and progrem counter stop please simulate this code