keyproc.c

MSP430的I2C模块

#include "chip.h"
#include "hdi2c.h"
#include "key.h"
#include "pcf8574.h"

unsigned char KeyProcess()
{
 unsigned char Key,i;
 const unsigned char KEY_ROW[]={KEY_ROW1,KEY_ROW2,KEY_ROW3};
 for(i=0;i<3;i++)
 {
  I2CTxByte(I2CWR_ADDR,KEY_ROW[i]);  
  Key=I2CRxByte(I2CRD_ADDR);
  if((Key & NO_KEY)!=NO_KEY)
  {
   I2CTxByte(I2CWR_ADDR,KEY_INIT+1);  
   return Key;
  } 
 }  
 I2CTxByte(I2CWR_ADDR,KEY_INIT);
 return 0;
}