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KeyPad problem with 16f877 PIC

 
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sharji



Joined: 14 Feb 2011
Posts: 3

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KeyPad problem with 16f877 PIC
PostPosted: Mon Feb 14, 2011 12:40 pm     Reply with quote
Hello

I am new at this forum so please help me.

I have a project and I have to take the value of the keypad and send the value by using rs232 or display it on LCD screen.

The problem I have is the LCD or RS232 is working fine without adding KBD code. After I write the code, the LCD is not displaying anything and the RS232 is stop transmitting!!

I am using flex drivers for the LCD and KBD and my controller is 16F877.


This is the main code:
Code:
 #include "LCD.c"
#include "Flex_KBD.c"


void main()
{
char k;
   setup_adc_ports(NO_ANALOGS);
   setup_adc(ADC_OFF);
   setup_psp(PSP_DISABLED);
   setup_spi(FALSE);
   setup_counters(RTCC_INTERNAL,RTCC_DIV_1);
   setup_timer_1(T1_DISABLED);
   setup_timer_2(T2_DISABLED,0,1);
   
   lcd_init();
   kbd_init();
   lcd_putc("\fReady...\n");
   delay_ms(100);
while(1)
{


 K=kbd_getc();

      while (K=='\0') { //Loop waiting for the key
         K=kbd_getc();
      delay_ms(10);
      }
   printf(lcd_putc, " char: %c\n",  K );
   delay_ms(100);
   

   


} // end of while
}// end of main

this is the keypad driver
Code:
///////////////////////////////////////////////////////////////////////////
////                             Flex_KBD.C                            ////
////                  Generic keypad scan driver                       ////
////                                                                   ////
////  kbd_init()   Must be called before any other function.           ////
////                                                                   ////
////  c = kbd_getc(c)  Will return a key value if pressed or /0 if not ////
////                   This function should be called frequently so as ////
////                   not to miss a key press.                        ////
////                                                                   ////
///////////////////////////////////////////////////////////////////////////


//Keypad connection: 

#define col0 PIN_E0
#define col1 PIN_E1
#define col2 PIN_E2
#define row0 PIN_D0
#define row1 PIN_D1
#define row2 PIN_D2
#define row3 PIN_D3

// Keypad layout:
char const KEYS[4][3] = {{'1','2','3'},
                         {'4','5','6'},
                         {'7','8','9'},
                         {'*','0','#'}};

#define KBD_DEBOUNCE_FACTOR 33    // Set this number to apx n/333 where
                                  // n is the number of times you expect
                                  // to call kbd_getc each second



void kbd_init() {
}


short int ALL_ROWS (void)
{
   if (input (row0) & input (row1) & input (row2) & input (row3))
      return (0);
   else
      return (1);
}



char kbd_getc( ) {
   static byte kbd_call_count;
   static short int kbd_down;
   static char last_key;
   static byte col;

   byte kchar;
   byte row;

   kchar='\0';
   if(++kbd_call_count>KBD_DEBOUNCE_FACTOR) {
       switch (col) {
         case 0   : output_low(col0);
               output_high(col1);
               output_high(col2);
                    break;
         case 1   : output_high(col0);
               output_low(col1);
               output_high(col2);
                    break;
         case 2   : output_high(col0);
               output_high(col1);
               output_low(col2);
                    break;
       }

       if(kbd_down) {
         if(!ALL_ROWS()) {
           kbd_down=false;
           kchar=last_key;
           last_key='\0';
         }
       } else {
          if(ALL_ROWS()) {
             if(!input (row0))
               row=0;
             else if(!input (row1))
               row=1;
             else if(!input (row2))
               row=2;
             else if(!input (row3))
               row=3;
             last_key =KEYS[row][col];
             kbd_down = true;
          } else {
             ++col;
             if(col==3)
               col=0;
          }
       }
      kbd_call_count=0;
   }
  return(kchar);
}

I want to know if my keypad is working fine or not and how to take the value from bottoms.

thanks Very Happy
PCM programmer



Joined: 06 Sep 2003
Posts: 21708

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PostPosted: Mon Feb 14, 2011 6:44 pm     Reply with quote
We can see the pins you are using for the keypad, but what pins are you
using for the LCD and the RS-232 ?
sharji



Joined: 14 Feb 2011
Posts: 3

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PostPosted: Tue Feb 15, 2011 12:42 am     Reply with quote
Code:

//LCD connection
// These pins are for the PIC development board:
// B1 enable
// B2 rs
// B3 rw
// B4 D4
// B5 D5
// E1 D6
// E0 D7


#define LCD_DB4   PIN_D0
#define LCD_DB5   PIN_D1
#define LCD_DB6   PIN_D2
#define LCD_DB7   PIN_D3

#define LCD_E     PIN_A1
#define LCD_RS    PIN_A3
#define LCD_RW    PIN_A2



connection of an RS-232 host through the DB9 connector.

I mentioned that the code of LCD is working fine without the line in the main code
Code:

K=kbd_getc();


once i commented it, the LCD works fine

I have used different pins for LCD and KBD as you see on the code but it did not work. Sad
sharji



Joined: 14 Feb 2011
Posts: 3

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PostPosted: Tue Feb 15, 2011 8:01 am     Reply with quote
Actually, I found that the pins that are used in LCD connections is same to the pins that are used in KBD connections, so I changed the pins that are connected to the KBD as following:
Code:


//Keypad connection: 

#define col0 PIN_E0
#define col1 PIN_E1
#define col2 PIN_E2
#define row0 PIN_B0
#define row1 PIN_B1
#define row2 PIN_B2
#define row3 PIN_B3


And the problem still the same, when I run the program without the following line, the program work fine and the LCD display what I want, but when I add the following line, the LCD does not display anything and sometimes display random things.
Code:

K=kbd_getc();
PCM programmer



Joined: 06 Sep 2003
Posts: 21708

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PostPosted: Tue Feb 15, 2011 11:30 pm     Reply with quote
1. Your while() loop in main() has large delays in it. You don't need them.
Look at the CCS example file, ex_kblcd.c, which shows how to use a
keypad and an LCD together in the same program:
Quote:

c:\program files\picc\examples\ex_lcdkb.c

Remove the main() code from your program in your first post in this
thread. Use the main() code from ex_lcdkb.c instead.

Also delete the 7 lines of setup code below from main(). They are not needed:
Quote:

setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_counters(RTCC_INTERNAL,RTCC_DIV_1);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);



2. You need pull-up resistors on the Row pins for the keypad. You have
used PortB for the Row pins, so you can use the built-in pullups in the
16F877. To do this, edit the Flex keypad driver file and add the line
shown in bold below to the kbd_init() function:
Quote:

void kbd_init()
{
port_b_pullups(TRUE);
}



If you do these changes, I think it has a chance to work.
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