lcd.c

This is an Real-Time Library (RL-ARM) Flash File System file manipulation example.

/*----------------------------------------------------------------------------
 *      R T L   K e r n e l   E x a m p l e
 *----------------------------------------------------------------------------
 *      Name:    LCD.C
 *      Purpose: LCD module 2x16 driver for ST7066 controller
 *      Rev.:    V3.12
 *----------------------------------------------------------------------------
 *      This code is part of the RealView Run-Time Library.
 *      Copyright (c) 2004-2007 KEIL - An ARM Company. All rights reserved.
 *---------------------------------------------------------------------------*/

#include <RTL.h>
#include <91x_lib.H>
#include "LCD.h"

/* LCD IO definitions */
#define LCD_DATA GPIO8->DR[0xFF<<2]     /* Data bits D0 = P8.0 .. DB7 = P8.7  */
#define LCD_E    GPIO9->DR[0x01<<2]     /* Enable control                     */
#define LCD_RW   GPIO9->DR[0x02<<2]     /* Read/Write control                 */
#define LCD_RS   GPIO9->DR[0x04<<2]     /* Data/Instruction control           */
#define LCD_CTRL GPIO9->DR[0x07<<2]     /* All 3 control lines (E/RW/RS)      */

#define E_ENA    0x01
#define E_DIS    0x00
#define RW_READ  0x02
#define RW_WRITE 0x00
#define RS_DATA  0x04
#define RS_INST  0x00

/* Local variables */
static U32 lcd_ptr;

/* 8 user defined characters to be loaded into CGRAM (used for bargraph) */
static const U8 UserFont[8][8] = {
  { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 },
  { 0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10 },
  { 0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18 },
  { 0x1C,0x1C,0x1C,0x1C,0x1C,0x1C,0x1C,0x1C },
  { 0x1E,0x1E,0x1E,0x1E,0x1E,0x1E,0x1E,0x1E },
  { 0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F },
  { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 },
  { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }
};

/* Local Function Prototypes */
static void delay (U32 cnt);
static void lcd_write (U32 c);
static U32  lcd_rd_stat (void);
static void lcd_wr_cmd (U32 c);
static void lcd_wr_data (U32 d);
static void lcd_wait_busy (void);

/*----------------------------------------------------------------------------
 * LCD Driver Interface Functions
 *---------------------------------------------------------------------------*/


/*--------------------------- delay -----------------------------------------*/

static void delay (U32 cnt) {
   /* Delay in while loop cycles. */

   while (cnt--);
}


/*--------------------------- lcd_write -------------------------------------*/

static void lcd_write (U32 c) {
   /* Write data/command to LCD controller. */

   GPIO8->DDR = 0xFF;
   LCD_RW     = RW_WRITE;
   LCD_DATA   = c;
   LCD_E      = E_ENA;
   delay (10);
   LCD_E      = E_DIS;
   delay (10);
}


/*--------------------------- lcd_rd_stat -----------------------------------*/

static U32 lcd_rd_stat (void) {
   /* Read status of LCD controller (ST7066) */
   U32 stat;

   GPIO8->DDR = 0x00;
   LCD_CTRL   = RW_READ;
   delay (10);
   LCD_E      = E_ENA;
   delay (10);
   stat       = LCD_DATA;
   LCD_E      = E_DIS;
   return (stat);
}


/*--------------------------- lcd_wait_busy ---------------------------------*/

static void lcd_wait_busy (void) {
   /* Wait until LCD controller (ST7066) is busy. */
   U32 stat;

   do {
      stat = lcd_rd_stat ();
   } while (stat & 0x80);               /* Wait for busy flag                */
}


/*--------------------------- lcd_wr_cmd ------------------------------------*/

static void lcd_wr_cmd (U32 c) {
   /* Write command to LCD controller. */

   lcd_wait_busy ();
   LCD_RS = RS_INST;
   lcd_write (c);
}


/*--------------------------- lcd_wr_data -----------------------------------*/

static void lcd_wr_data (U32 d) {
   /* Write data to LCD controller. */

   lcd_wait_busy ();
   LCD_RS = RS_DATA;
   lcd_write (d);
}


/*--------------------------- LCD_init --------------------------------------*/

void LCD_init (void) {
   /* Initialize the ST7066 LCD controller to 4-bit mode. */ 

   GPIO8->DDR  = 0xFF;
   GPIO9->DDR |= 0x07;
   LCD_CTRL    = RS_INST;

   lcd_write (0x38);                    /* Select 8-bit interface            */
   delay (100000);
   lcd_write (0x38);
   delay (10000);
   lcd_write (0x38);

   lcd_write (0x38);                    /* 2 lines, 5x8 character matrix     */
   lcd_wr_cmd (0x0e);                   /* Display ctrl:Disp/Curs/Blnk=ON    */
   lcd_wr_cmd (0x06);                   /* Entry mode: Move right, no shift  */

   LCD_load ((U8 *)&UserFont, sizeof (UserFont));
   LCD_cls ();
}


/*--------------------------- LCD_load --------------------------------------*/

void LCD_load (U8 *fp, U32 cnt) {
   /* Load user-specific characters into CGRAM */
   U32 i;

   lcd_wr_cmd (0x40);                   /* Set CGRAM address counter to 0    */
   for (i = 0; i < cnt; i++, fp++)  {
      lcd_wr_data (*fp);
   }
}

/*--------------------------- LCD_gotoxy ------------------------------------*/

void LCD_gotoxy (U32 x, U32 y) {
   /* Set cursor position on LCD display. Left corner: 1,1, right: 16,2 */
   U32 c;

   c = --x;
   if (--y) {
      c |= 0x40;
   }
   lcd_wr_cmd (c | 0x80);
   lcd_ptr = y*16 + x;
}


/*--------------------------- LCD_cls ---------------------------------------*/

void LCD_cls (void) {
   /* Clear LCD display, move cursor to home position. */

   lcd_wr_cmd (0x01);
   LCD_gotoxy (1,1);
}


/*--------------------------- LCD_cur_off------------------------------------*/

void LCD_cur_off (void) {
   /* Switch off LCD cursor. */

   lcd_wr_cmd (0x0c);
}


/*--------------------------- LCD_on ------ ---------------------------------*/

void LCD_on (void) {
   /* Switch on LCD and enable cursor. */

   lcd_wr_cmd (0x0e);
}


/*--------------------------- LCD_putc --------------------------------------*/

void LCD_putc (U8 c) { 
   /* Print a character to LCD at current cursor position. */

   if (lcd_ptr == 16) {
      lcd_wr_cmd (0xc0);
   }
   lcd_wr_data (c);
   lcd_ptr++;
}


/*--------------------------- LCD_puts --------------------------------------*/

void LCD_puts (U8 *sp) {
   /* Print a string to LCD display. */

   while (*sp) {
      LCD_putc (*sp++);
   }
}

/*--------------------------- LCD_bargraph ----------------------------------*/

void LCD_bargraph (U32 val, U32 size) {
   /* Print a bargraph to LCD display.  */
   /* - val:  value 0..100 %            */
   /* - size: size of bargraph 1..16    */
   U32 i;

   val = val * size / 20;               /* Display matrix 5 x 8 pixels       */
   for (i = 0; i < size; i++) {
      if (val > 5) {
         LCD_putc (5);
         val -= 5;
      }
      else {
         LCD_putc (val);
         break;
      }
   }
}

/*----------------------------------------------------------------------------
 * end of file
 *---------------------------------------------------------------------------*/