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HTEB1
User manual
Issue 0.2 Page 36 07/2002
3.2 LCD
One of the highlights of the HTEB1 is the 2*16 character LCD with
backlight. Simple functions are provided here to demonstrate the usage of
the LCD. Please refer to the LCD manual for further information (e.g.
commands, other character sets etc.).
The demo source contains some definitions to reset and initialise the
display. Then we make some simple write outs.
/*------------------------------------------------------------------
** LCDDemo shows some funcions of the LCD on the TinyEvalBoard
** Please refer to LCD datasheet for further details
**-----------------------------------------------------------------*/
#include "mydefs.h" // find further includes there!
void wait(u16 wastetime) // local LCD port delay
{
while(wastetime--);
}
/*
LCD-Port / Bits on TinyEvalBoard
RS = P75, R/W = P74, EN = P20, DATA = P5
*/
// some defines for easy access
#define CLEAR_LCD_RS (PDR7 &= ~0x20)
#define SET_LCD_RS (PDR7 |= 0x20)
#define CLEAR_LCD_RW (PDR7 &= ~0x10)
#define SET_LCD_RW (PDR7 |= 0x10)
#define CLEAR_LCD_EN (PDR2 &= ~0x01)
#define SET_LCD_EN (PDR2 |= 0x01)
#define LCD_DATA_PORT (PDR5)
#define LCD_DATA_CTRL (PCR5)
#define LCD_OUT 0xff
#define LCD_IN 0x00
#define LCD_WAIT {wait(100);}
void LCDWriteCmd(u8 cmd) // write cmd to LCD port
{
CLEAR_LCD_RS;
CLEAR_LCD_RW;
SET_LCD_EN;
LCD_DATA_PORT = cmd;
LCD_WAIT;
CLEAR_LCD_EN;
LCD_WAIT;
}
void LCDWriteData(u8 data) // write data to LCD port
{
SET_LCD_RS;
CLEAR_LCD_RW;
SET_LCD_EN;
LCD_DATA_PORT = data;
LCD_WAIT;
CLEAR_LCD_EN;
LCD_WAIT;
}