i2cmstlm75.c

NXP产品LPC23XX的开发板的源文件

/*****************************************************************************
 *   i2cmst.c:  main C entry file for Philips LPC23xx/24xx Family Microprocessors
 *
 *   Copyright(C) 2006, Philips Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2006.07.20  ver 1.00    Prelimnary version, first Release
 *
******************************************************************************/
#include "LPC230x.h"                        /* LPC23xx/24xx definitions */
#include "type.h"
#include "irq.h"
#include "i2clm75.h"

extern DWORD I2CCount;
extern BYTE I2CMasterBuffer[BUFSIZE];
extern DWORD I2CCmd, I2CMasterState;
extern DWORD I2CReadLength, I2CWriteLength;

/*******************************************************************************
**   Main Function  main()
*******************************************************************************/
DWORD I2CReadTemp (void)
{
    DWORD i;

#if 0
    init_VIC();
    if ( I2CInit( (DWORD)I2CMASTER ) == FALSE )	/* initialize I2c */
    {
		while ( 1 );				/* Fatal error */
    }
#endif

    /* the example used to test the I2C interface is 
    a Philips's LM75 temp sensor. MCB2300 is used a I2C
    master, the temp sensor is a I2C slave.
    
    the sequence to get the temp reading is: 
	get device ID register,
	set configuration register,
	get temp reading

    In order to start the I2CEngine, the all the parameters 
    must be set in advance, including I2CWriteLength, I2CReadLength,
    I2CCmd, and the I2cMasterBuffer which contains the stream
    command/data to the I2c slave device. */

    /* Configure temp register before reading */
    for ( i = 0; i < BUFSIZE; i++ )	/* clear buffer */
    {
		I2CMasterBuffer[i] = 0;
    }
    I2CWriteLength = 2;
    I2CReadLength = 0;
    I2CMasterBuffer[0] = LM75_ADDR;
    I2CMasterBuffer[1] = LM75_CONFIG;
    I2CMasterBuffer[2] = 0x00;		/* configuration value, no change from 
									default */
    I2CCmd = LM75_CONFIG;
    I2CEngine(); 

    /* Get temp reading */
    for ( i = 0; i < BUFSIZE; i++ )	/* clear buffer */
    {
		I2CMasterBuffer[i] = 0;
    }
    I2CWriteLength = 1;
    I2CReadLength = 2;
    I2CMasterBuffer[0] = LM75_ADDR;
    I2CMasterBuffer[1] = LM75_TEMP;
    I2CMasterBuffer[2] = LM75_ADDR | RD_BIT;
    I2CCmd = LM75_TEMP;
    I2CEngine();

    /* The temp reading value should reside in I2CMasterBuffer byte 3, 4, ... */ 
    return 0;
}

/******************************************************************************
**                            End Of File
******************************************************************************/