LCD Menu integration with 4x4 keypad (c programming)

[unexpert]

Hi,

I've been working on a project using MPLAB IDE v8.36.

I'm trying to make a menu using the keypad for eg,

1 pressed - measure heart rate
2 pressed - exit

We can't get the output when we press the allocated key.

Here is our programme code below:

#include <p18f4520.h>
#include <delays.h>

unsigned int LCD(void);
unsigned int EXIT(void);

void Init_LCD(void);
void w_ctr_8bit(char);
void w_data_8bit(char);
void Delay_1kcyc(void);

#define LCD_DATA PORTD
#define LCD_RS PORTBbits.RB1
#define LCD_E PORTBbits.RB2

unsigned char LCD_TEMP, i,j,k,m;
char MESS[16]=" WELCOME TO ECG ";
char MESS2[16]="1.MEASURE 2.EXIT";

void main()

{
unsigned int x, y, value;
ADCON1=0x0F;
TRISA=0xFF;
TRISB=0;
TRISD=0;
y=value;
PORTD=1;
Init_LCD();
w_ctr_8bit(0b10000000);
for (i=0; i<16; i++)
w_data_8bit(MESS[i]);

w_ctr_8bit(0b11000000);
for (i=0; i<16; i++)
w_data_8bit(MESS2[i]);

LCD();

while(1)
{ if (value==0b00000001)
for(i=0;i<16;i++)
{

unsigned int EXIT();
}
}


}






unsigned int LCD(void)
{
char value, keyInputs;
while(PORTAbits.RA4==0);
keyInputs = PORTA & 0x0F;
switch(keyInputs)
{
case 0: value='1';w_data_8bit(value);break;
case 1: value='2';w_data_8bit(value);break;
case 2: value='3';w_data_8bit(value);break;
case 3: value='F';w_data_8bit(value);break;
case 4: value='4';w_data_8bit(value);break;
case 5: value='5';w_data_8bit(value);break;
case 6: value='6';w_data_8bit(value);break;
case 7: value='E';w_data_8bit(value);break;
case 8: value='7';w_data_8bit(value);break;
case 9: value='8';w_data_8bit(value);break;
case 10: value='9';w_data_8bit(value);break;
case 11: value='D';w_data_8bit(value);break;
case 12: value='A';w_data_8bit(value);break;
case 13: value='0';w_data_8bit(value);break;
case 14: value='B';w_data_8bit(value);break;
case 15: value='C';w_data_8bit(value);break;
}
Delay10KTCYx(50);
return(value);
}

void Init_LCD()
{
w_ctr_8bit(0b00111000);
w_ctr_8bit(0b00001100);
w_ctr_8bit(0b00000110);
w_ctr_8bit(0b00000001);
w_ctr_8bit(0b00000010);
w_ctr_8bit(0b10000010);
}

void w_ctr_8bit(char w)
{
LCD_RS = 0;
LCD_E = 1;
LCD_DATA = w;
LCD_E = 0;
Delay10TCYx(50);
}

void w_data_8bit(char w)
{
LCD_RS = 1;
LCD_E = 1;
LCD_DATA = w;
LCD_E = 0;
Delay10TCYx(50);
}

unsigned int EXIT(void)
{
char MESS3[16]="THANK YOU FOR";
char MESS4[16]="USING ECG, BYE!";

w_ctr_8bit(0b10000000);
for (i=0; i<16; i++)
w_data_8bit(MESS3[i]);

w_ctr_8bit(0b11000000);
for (i=0; i<16; i++)
w_data_8bit(MESS4[i]);
}

We would appreciate help. Thanks ..

[Salem]

First thing is learning about formatting code.

#include <p18f4520.h>
#include <delays.h>

unsigned int LCD(void);
unsigned int EXIT(void);

void Init_LCD(void);
void w_ctr_8bit(char);
void w_data_8bit(char);
void Delay_1kcyc(void);

#define LCD_DATA PORTD
#define LCD_RS PORTBbits.RB1
#define LCD_E PORTBbits.RB2

unsigned char LCD_TEMP, i,j,k,m;
char MESS[16]=" WELCOME TO ECG ";
char MESS2[16]="1.MEASURE 2.EXIT";

void main()
{
  unsigned int x, y, value;
  ADCON1=0x0F;
  TRISA=0xFF;
  TRISB=0;
  TRISD=0;
  y=value;
  PORTD=1;

  Init_LCD();

  w_ctr_8bit(0b10000000);
  for (i=0; i<16; i++)
    w_data_8bit(MESS[i]);

  w_ctr_8bit(0b11000000);
  for (i=0; i<16; i++)
    w_data_8bit(MESS2[i]);

  LCD();

  while(1)
  { 
    if (value==0b00000001)
      for(i=0;i<16;i++)
      {
        unsigned int EXIT();
      }
  }
}

unsigned int LCD(void)
{
  char value, keyInputs;
  while(PORTAbits.RA4==0);
  keyInputs = PORTA & 0x0F;
  switch(keyInputs)
  {
  case 0: value='1';w_data_8bit(value);break;
  case 1: value='2';w_data_8bit(value);break;
  case 2: value='3';w_data_8bit(value);break;
  case 3: value='F';w_data_8bit(value);break;
  case 4: value='4';w_data_8bit(value);break;
  case 5: value='5';w_data_8bit(value);break;
  case 6: value='6';w_data_8bit(value);break;
  case 7: value='E';w_data_8bit(value);break;
  case 8: value='7';w_data_8bit(value);break;
  case 9: value='8';w_data_8bit(value);break;
  case 10: value='9';w_data_8bit(value);break;
  case 11: value='D';w_data_8bit(value);break;
  case 12: value='A';w_data_8bit(value);break;
  case 13: value='0';w_data_8bit(value);break;
  case 14: value='B';w_data_8bit(value);break;
  case 15: value='C';w_data_8bit(value);break;
  }
  Delay10KTCYx(50);
  return(value);
}

void Init_LCD()
{
  w_ctr_8bit(0b00111000);
  w_ctr_8bit(0b00001100);
  w_ctr_8bit(0b00000110);
  w_ctr_8bit(0b00000001);
  w_ctr_8bit(0b00000010);
  w_ctr_8bit(0b10000010);
}

void w_ctr_8bit(char w)
{
  LCD_RS = 0;
  LCD_E = 1;
  LCD_DATA = w;
  LCD_E = 0;
  Delay10TCYx(50);
}

void w_data_8bit(char w)
{
  LCD_RS = 1;
  LCD_E = 1;
  LCD_DATA = w;
  LCD_E = 0;
  Delay10TCYx(50);
}

unsigned int EXIT(void)
{
  char MESS3[16]="THANK YOU FOR";
  char MESS4[16]="USING ECG, BYE!";

  w_ctr_8bit(0b10000000);

  for (i=0; i<16; i++)
    w_data_8bit(MESS3[i]);

  w_ctr_8bit(0b11000000);

  for (i=0; i<16; i++)
    w_data_8bit(MESS4[i]);
}

Next, line 47 is a prototype for EXIT(), not a call to EXIT()

[unexpert]

Thanks for replying. So how do I call it as a function instead of a prototype?

[Salem]

Look at the other examples of calling functions that you've already managed.

What an odd thing to say, it's like you've been given this code and told to fix it.

[Domade]

Hi Salem,

In the above C code, is debouncing not required for the 4x4 keypad? why is it so?

i'm also intending to use a 4x4 matrix keypad for my project and i really wish to learn how to use it well.

Do u mind sparing some time to explain the keypad?

Your help will be greatly appreciated.Thks

[Salem]

Not my code, not my hardware - how would I know.

Maybe it's debounced in hardware and maybe it isn't.
That's down to you to figure out from reading the hardware specs.