#1
Dear Friends, can you help me about internal/ external EEPROM programming in PIC16F877A microcontroller. I have written but it is not displaced in LCDs.
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// LCD module connections
sbit LCD_RS at RB4_bit;
sbit LCD_EN at RB5_bit;
sbit LCD_D4 at RB0_bit;
sbit LCD_D5 at RB1_bit;
sbit LCD_D6 at RB2_bit;
sbit LCD_D7 at RB3_bit;
sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;
// End LCD module connections
void WriteEEPROM( char Addr, char Data) ;
char ReadEEPROM( char addr) ;
void port_confg( ) ;
Lcd_Init( ) ;
Lcd_Cmd( _LCD_CLEAR) ; // Clear display
Lcd_Cmd( _LCD_CURSOR_OFF) ; // Cursor off
void main( )
{
char WriteEEPROM( char Addr, char Data) ;
char ReadEEPROM( char addr) ;
port_confg( ) ;
Delay_ms( 2000 ) ;
while ( 1 )
{
}
}
void port_confg( )
{
PORTB = 0 ;
PORTA = 0 ;
TRISB = 0b00001111 ;
TRISA = 0b00100000 ;
}
char WriteEEPROM( char Addr, char Data)
{
while ( EECON1.WR == 1 ) ;
EEADR = Addr;
EEDATA = Data;
EECON1.EEPGD = 0 ; // 0 = Access data EEPROM memory
EECON1.WREN = 1 ; // enable writes to internal EEPROM
EECON2 = 0x55 ; // Required sequence for write to internal EEPROM
EECON2 = 0xAA ; // Required sequence for write to internal EEPROM
EECON1.WR = 1 ; // begin write to internal EEPROM
EECON1.WREN = 0 ;
}
char ReadEEPROM( char addr)
{
EEADR = addr;
EECON1.EEPGD = 0 ;
EECON1.RD = 1 ;
asm nop; asm nop;
return EEDATA;
}
Last edited by a moderator: May 21, 2012