i2c.c

基于温度传感器LM35与PIC16F877A的应用程序

#include <pic.h> 
#define portbit(address,bits) ((unsigned)(&address)*8 + (bits)) 
#define BUSY 0x80 
#define WRITE_DATA 0xff 
#define delay_data 0xff 
#define COMMAND 0x00 
#define LCD_CLEAR 0x01 
#define portdata PORTB 
#define READ 0xa1
#define WRITE 0xa0
#define eeprom_address 0x00

volatile bit E  @ portbit(PORTD,7); 
volatile bit RW @ portbit(PORTD,6); 
volatile bit RS @ portbit(PORTD,5); 
volatile bit reload;
volatile unsigned char dispdata;

void delay(unsigned int delay_time) 
{ 
  unsigned char i;
  while (delay_time--)
  {
   for (i = 0; i <0xff; i ++)
    {
      } 
   }
}  

void i2c_init(void)
 {
  INTCON = 0x00;
  SSPSTAT = 0x80;
  SSPCON = 0x08;
  SSPCON2 = 0x00;
  SSPADD = 0x02;
  TRISC4 = 1;
  TRISC3 = 1;
  SSPIF = 0;
  SSPIE = 0;
  di();
  SSPEN = 1;
 }
  
void i2c_send(unsigned char data)
 {
  unsigned char i;
  SEN = 1;
  for (i = 2; -- i;)
  continue;
  do 
    {
      RSEN = 1;
       }
  while (SSPIF == 0);
  SSPIF = 0;
  SSPBUF = WRITE;
  while (SSPIF == 0);
  SSPIF = 0;
  SSPBUF = eeprom_address;
  while (SSPIF == 0);
  SSPIF = 0;
  SSPBUF = data;
  while (SSPIF == 0);
  SSPIF = 0;
  PEN = 1;
  while (SSPIF == 0);
  SSPIF = 0;
  }
unsigned char i2c_receive(void)
 {
  unsigned char temp;
  unsigned char i;
  SEN = 1;
  for (i = 2; -- i;)
   {
     }
  while (SSPIF == 0);
  SSPIF = 0;
  SSPBUF = WRITE;
  while (SSPIF == 0);
  SSPIF = 0;
  SSPBUF = eeprom_address;
  while (SSPIF == 0);
  SSPIF = 0;
  do
   {
     RSEN = 1;
     }
  while (SSPIF == 0);
  SSPIF = 0;
  SSPBUF = READ;
  while (SSPIF == 0);
  SSPIF = 0;
  while (SSPIF == 0);
  temp = SSPBUF;
  SSPIF = 0;
  PEN = 1;
  while (SSPIF == 0);
  SSPIF = 0;
  return temp;
 }
unsigned char lcd_busy(void) 
{ 
  unsigned char temp; 
   
  portdata = 0xff; 
  RS = 0; 
  RW = 1; 
  E = 1; 
  TRISB = 0xff; 
  temp = portdata; 
  TRISB = 0x00; 
  E = 0; 
  return (temp); 
} 

void lcd_command_writedata(unsigned char check,unsigned char data) 
{ 
  if (check == COMMAND) 
  { 
   RS = 0; 
   } 
  else 
  { 
   RS = 1; 
  } 
  RW = 0; 
  portdata = data; 
  E = 1; 
  E = 0; 
  while (lcd_busy() & BUSY); 
} 

void lcd_disp(unsigned char adr,unsigned char disp_data) 
{ 
 lcd_command_writedata(COMMAND,adr);
 lcd_command_writedata(WRITE_DATA,disp_data);
} 

void lcd_init(void) 
{ 
  lcd_command_writedata(COMMAND,LCD_CLEAR); 
  lcd_command_writedata(COMMAND,0x38); 
  lcd_command_writedata(COMMAND,0x0e); 
  lcd_command_writedata(COMMAND,0x06); 
} 
void system_init(void) 
{ 
  INTCON = 0x00; 
  OPTION = 0xff;
  TRISB = 0x00; 
  TRISD = 0x00; 
} 

void main(void) 
{ 
 system_init(); 
 lcd_init();
 i2c_init();
 dispdata = 0x38;
 i2c_send(dispdata);
 dispdata = 0x00;
 dispdata = i2c_receive();
 lcd_disp(0x84,0X35);
 lcd_disp(0x85,dispdata);
 while (1) 
 { 
  } 
}