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LCD driver problem

 
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monkeytennis



Joined: 18 Feb 2004
Posts: 16
Location: UK

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LCD driver problem
PostPosted: Wed Jul 21, 2004 8:40 am     Reply with quote

Hi.

I have a circuit built (as in http://ww1.microchip.com/downloads/en/AppNotes/00582b.pdf) and I need it now to do something else. Quite simply it is used to set a day counter and when the countdown is finished, an output pin goes high. I however, have attempted to write a suitable program and have (hopefully) adjusted the LCD.C driver so that it should work, but it doesn't. Can anyone see if there is something obvious that I have done wrong?

(Oh yeah timer1 is driven from an external 32.768KHz watch crystal)

Cheers,
Simon

Code:
// Main C program
#include <16C64A.h>
#include <LCD2.C>
#use delay(clock=4000000)
#fuses HS, NOPUT, NOWDT, NOPROTECT, NOBROWNOUT

//Defitions below make it easy to change the settings without playing with the
//program.  Change COUNTDOWN to 'days' or 'hours'.
#define COUNTDOWN hours
#define FIRE_PIN1 PIN_C6
#define FIRE_PIN2 PIN_C7
#define UP_PIN PIN_B7
#define SET_PIN PIN_B6

void update_lcddays(void);

int secs=0,hours=0,days=0,dayset=0;
int1 debounce=0;

#int_TIMER1
TIMER1_isr()
{
   set_timer1(0xF000);
   secs++;
   if (secs==3600)
   {
      secs=0;
      hours++;
   }
   if (hours==24)
   {
      hours=0;
      days++;
   }
   if (COUNTDOWN==dayset)
   {
      disable_interrupts(global);
      output_high(FIRE_PIN1);
      for (secs=0;secs<60;secs++)
         delay_ms(100);
      output_high(FIRE_PIN2);
   }
}



void main()
{
   int1 set=0,update=1;
   int a;
   setup_psp(PSP_DISABLED);
   setup_spi(FALSE);
   port_b_pullups(TRUE);
   setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
   setup_timer_1(T1_EXTERNAL|T1_DIV_BY_8);
   setup_timer_2(T2_DISABLED,0,1);
   lcd_init();
   enable_interrupts(INT_TIMER1);
   enable_interrupts(global);

   disable_interrupts(global);
   output_float(UP_PIN);
   output_float(SET_PIN);
   printf(lcd_putc,"\fChange days setting: %3d",dayset);
   do
   {
      if (input(UP_PIN)==0)
      {
         update=1;
         for (a=0;a<10;a++)
            if (input(UP_PIN))
               update=0;
            else
               delay_ms(100);
         if (update)
         {
            dayset++;
            if (dayset==1000)
               dayset=0;
            printf(lcd_putc,"\fChange days setting: %3d",dayset);
         }
      }
      if (input(SET_PIN)==0)
      {
         set=1;
         for (a=0;a<100;a++)
            if (input(SET_PIN))
               set=0;
            else
               delay_ms(100);
      }
   }while(set==0);
   printf(lcd_putc,"\fSet for %d days",dayset);
   enable_interrupts(global);
   while(true);
}

///////////////////////////////////////////////////////////////////////////
////                             LCDD.C                                ////
////                 Driver for common LCD modules                     ////
////                                                                   ////
////  lcd_init()   Must be called before any other function.           ////
////                                                                   ////
////  lcd_putc(c)  Will display c on the next position of the LCD.     ////
////                     The following have special meaning:           ////
////                      \f  Clear display                            ////
////                      \n  Go to start of second line               ////
////                      \b  Move back one position                   ////
////                                                                   ////
////  lcd_gotoxy(x,y) Set write position on LCD (upper left is 1,1)    ////
////                                                                   ////
////  lcd_getc(x,y)   Returns character at position x,y on LCD         ////
////                                                                   ////
///////////////////////////////////////////////////////////////////////////
////        (C) Copyright 1996,2003 Custom Computer Services           ////
//// This source code may only be used by licensed users of the CCS C  ////
//// compiler.  This source code may only be distributed to other      ////
//// licensed users of the CCS C compiler.  No other use, reproduction ////
//// or distribution is permitted without written permission.          ////
//// Derivative programs created using this software in object code    ////
//// form are not restricted in any way.                               ////
///////////////////////////////////////////////////////////////////////////

// As defined in the following structure the pin connection is as follows:
#define enable  PIN_A0
#define rs      PIN_A2
#define rw      PIN_A1
#define D4      PIN_B0
#define D5      PIN_B1
#define D6      PIN_B2
#define D7      PIN_B3
#define TEST    PIN_A3
//
//   LCD pins D0-D3 are not used and PIC D3 is not used.

// Un-comment the following define to use port B
// #define use_portb_lcd TRUE

#byte PORTB = 6
#define IN 0xFF
#define OUT 0

/*
struct lcd_pin_map {                 // This structure is overlayed
           BOOLEAN enable;           // on to an I/O port to gain
           BOOLEAN rs;               // access to the LCD pins.
           BOOLEAN rw;               // The bits are allocated from
           BOOLEAN unused;           // low order up.  ENABLE will
           int     data : 4;         // be pin B0.
        } lcd;


#if defined(__PCH__)
#if defined use_portb_lcd
   #byte lcd = 0xF81                   // This puts the entire structure
#else
   #byte lcd = 0xF83                   // This puts the entire structure
#endif
#else
#if defined use_portb_lcd
   #byte lcd = 6                  // on to port B (at address 6)
#else
   #byte lcd = 8                 // on to port D (at address 8)
#endif
#endif

#if defined use_portb_lcd
   #define set_tris_lcd(x) set_tris_b(x)
#else
   #define set_tris_lcd(x) set_tris_d(x)
#endif

*/


#define lcd_type 2           // 0=5x7, 1=5x10, 2=2 lines
#define lcd_line_two 0x40    // LCD RAM address for the second line


BYTE const LCD_INIT_STRING[4] = {0x20 | (lcd_type << 2), 0xc, 1, 6};
                             // These bytes need to be sent to the LCD
                             // to start it up.


                             // The following are used for setting
                             // the I/O port direction register.

//struct lcd_pin_map const LCD_WRITE = {0,0,0,0,0}; // For write mode all pins are out
//struct lcd_pin_map const LCD_READ = {0,0,0,0,15}; // For read mode data pins are in



BYTE lcd_read_byte() {
      BYTE low,high;
      output_high(TEST);
      output_float(D4);
      output_float(D5);
      output_float(D6);
      output_float(D7);
      output_high(rw);
      delay_cycles(1);
      output_high(enable);
      delay_cycles(1);
      set_tris_b(IN);
      high = PORTB & 0x0F;
      output_low(enable);
      delay_cycles(1);
      output_high(enable);
      delay_us(1);
      low = PORTB & 0x0F;
      output_low(enable);
      set_tris_b(OUT);
      output_low(TEST);
      return( (high<<4) | low);
}


void lcd_send_nibble( BYTE n ) {
      set_tris_b(OUT);
      PORTB = n & 0x0F;
      delay_cycles(1);
      output_high(enable);
      delay_us(2);
      output_low(enable);
}


void lcd_send_byte( BYTE address, BYTE n ) {
      output_high(TEST);
      output_low(rs);
      while (input(D7)) ;
      if (address==0)
         output_low(rs);
      else
         output_high(rs);
      delay_cycles(1);
      output_low(rw);
      delay_cycles(1);
      output_low(enable);
      lcd_send_nibble(n >> 4);
      lcd_send_nibble(n & 0xf);
      output_low(TEST);
}


void lcd_init() {
    BYTE i;
    set_tris_b(OUT);
    output_low(rs);
    output_low(rw);
    output_low(enable);
    delay_ms(15);
    for(i=1;i<=3;++i) {
       lcd_send_nibble(3);
       delay_ms(5);
    }
    lcd_send_nibble(2);
    for(i=0;i<=3;++i)
       lcd_send_byte(0,LCD_INIT_STRING[i]);
}


void lcd_gotoxy( BYTE x, BYTE y) {
   BYTE address;

   if(y!=1)
     address=lcd_line_two;
   else
     address=0;
   address+=x-1;
   lcd_send_byte(0,0x80|address);
}

void lcd_putc( char c) {
   switch (c) {
     case '\f'   : lcd_send_byte(0,1);
                   delay_ms(2);
                                           break;
     case '\n'   : lcd_gotoxy(1,2);        break;
     case '\b'   : lcd_send_byte(0,0x10);  break;
     default     : lcd_send_byte(1,c);     break;
   }
}

char lcd_getc( BYTE x, BYTE y) {
   char value;

    lcd_gotoxy(x,y);
    while (input(D7)); // wait until busy flag is low
    output_high(rs);
    value = lcd_read_byte();
    output_low(rs);
    return(value);
}
Mark



Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA

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PostPosted: Wed Jul 21, 2004 11:12 am     Reply with quote

Here is a version of LCDD.C that I did sometime back allowing the control signals to be on different ports than the data. I changed it per App582. It is untested so try it if you want.

Code:

////////////////////////////////////////////////////////////////////////////
////                             LCDD.C                                 ////
////                 Driver for common LCD modules                      ////
////                                                                    ////
////  lcd_init()   Must be called before any other function.            ////
////                                                                    ////
////  lcd_putc(c)  Will display c on the next position of the LCD.      ////
////                     The following have special meaning:            ////
////                      \f  Clear display                             ////
////                      \n  Go to start of second line                ////
////                      \b  Move back one position                    ////
////                                                                    ////
////  lcd_gotoxy(x,y) Set write position on LCD (upper left is 1,1)     ////
////                                                                    ////
////  lcd_getc(x,y)   Returns character at position x,y on LCD          ////
////                                                                    ////
////////////////////////////////////////////////////////////////////////////
////        (C) Copyright 1996,1997 Custom Computer Services            ////
//// This source code may only be used by licensed users of the CCS C   ////
//// compiler.  This source code may only be distributed to other       ////
//// licensed users of the CCS C compiler.  No other use, reproduction  ////
//// or distribution is permitted without written permission.           ////
//// Derivative programs created using this software in object code     ////
//// form are not restricted in any way.                                ////
////////////////////////////////////////////////////////////////////////////

// This structure is overlayed onto the data ports so that you may use
// whatever ports you desire
struct lcd_pin_map

  BOOLEAN enable;     // PinA0
  BOOLEAN rw;         // PinA1
  BOOLEAN rs;         // PinA2
  BOOLEAN dummy;      // PinA3 is not used
  int unusedA  : 4;   // The rest of portA
  int     data : 4;   // lower nibble of portB is used for data lines
  int unusedB  : 4;   // The rest of portB
  int unusedC;        // portC is not used
  int unusedD;        // portD is not used
} lcd;
#if defined(__PCH__)
  #locate lcd = 0xF80
#else
  #locate lcd = 5
#endif

struct lcd_tris_map
{
  int control  : 3;
  BOOLEAN dummy;      // PinA3 is not used
  int unusedA  : 4;   // The rest of portA
  int    data  : 4;   // lower nibble of portB is used for data lines
  int unusedB  : 4;   // The rest of portB
  int unusedC;        // portC is not used
  int unusedD;        // portD is not used
} lcdtris;

#if defined(__PCH__)
  #locate lcdtris = 0xF92
#else
  #locate lcdtris = 0x85
#endif

#define set_tris_lcd(x) lcdtris.data = (x); lcdtris.control = 0;



#define lcd_type 2           // 0=5x7, 1=5x10, 2=2 lines
#define lcd_line_two 0x40    // LCD RAM address for the second line


BYTE const LCD_INIT_STRING[4] = {0x20 | (lcd_type << 2), 0xc, 1, 6};
                             // These bytes need to be sent to the LCD
                             // to start it up.


                             // The following are used for setting
                             // the I/O port direction register.

#define LCD_WRITE    0       // For write mode all pins are out
#define LCD_READ     15      // For read mode data pins are in

BYTE lcd_read_byte() {
      BYTE low,high;
      set_tris_lcd(LCD_READ);
      lcd.rw = 1;
      delay_cycles(1);
      lcd.enable = 1;
      delay_cycles(1);
      high = lcd.data;
      lcd.enable = 0;
      delay_cycles(1);
      lcd.enable = 1;
      delay_us(1);
      low = lcd.data;
      lcd.enable = 0;
      set_tris_lcd(LCD_WRITE);
      return( (high<<4) | low);
}


void lcd_send_nibble( BYTE n ) {
      lcd.data = n;
      delay_cycles(1);
      lcd.enable = 1;
      delay_us(2);
      lcd.enable = 0;
}


void lcd_send_byte( BYTE address, BYTE n ) {

      lcd.rs = 0;
      while ( bit_test(lcd_read_byte(),7) ) ;
      lcd.rs = address;
      delay_cycles(1);
      lcd.rw = 0;
      delay_cycles(1);
      lcd.enable = 0;
      lcd_send_nibble(n >> 4);
      lcd_send_nibble(n & 0xf);
}


void lcd_init() {
    BYTE i;
    set_tris_lcd(LCD_WRITE);
    lcd.rs = 0;
    lcd.rw = 0;
    lcd.enable = 0;
    delay_ms(15);
    for(i=1;i<=3;++i) {
       lcd_send_nibble(3);
       delay_ms(5);
    }
    lcd_send_nibble(2);
    for(i=0;i<=3;++i)
       lcd_send_byte(0,LCD_INIT_STRING[i]);
}


void lcd_gotoxy( BYTE x, BYTE y) {
   BYTE address;

   if(y!=1)
     address=lcd_line_two;
   else
     address=0;
   address+=x-1;
   lcd_send_byte(0,0x80|address);
}

void lcd_putc( char c) {
   switch (c) {
     case '\f'   : lcd_send_byte(0,1);
                   delay_ms(2);
                                           break;
     case '\n'   : lcd_gotoxy(1,2);        break;
     case '\b'   : lcd_send_byte(0,0x10);  break;
     default     : lcd_send_byte(1,c);     break;
   }
}

char lcd_getc( BYTE x, BYTE y) {
   char value;

    lcd_gotoxy(x,y);
    lcd.rs=1;
    value = lcd_read_byte();
    lcd.rs=0;
    return(value);
}


monkeytennis



Joined: 18 Feb 2004
Posts: 16
Location: UK

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PostPosted: Thu Jul 22, 2004 3:13 am     Reply with quote

Cheers, I'll give that a bash!

Simon
monkeytennis



Joined: 18 Feb 2004
Posts: 16
Location: UK

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PostPosted: Thu Jul 22, 2004 7:09 am     Reply with quote

Cheers for that, it worked spot-on first time. Now I've just gotta work out why the rest of it doesn't work. Wink

Simon
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