lm75.c

数字温度传感器LM75的使用与温度测量的C程序

/****************************************Copyright (c)**************************************************
**                               Guangzhou ZHIYUAN ELECTRONIC CO.,LTD.
**                                      Research centre
**                         http://www.zyinside.com, http://www.zlgmcu.com
**
**---------------------------------------File Info-----------------------------------------------------
** File name:			  LM75.c
** Latest modified Date:  2006-2-20
** Latest Version:		  1.0
** Descriptions:		  LM75 driver                        
**
**------------------------------------------------------------------------------------------------------
** Created by:			  ZhouShuwu
** Created date:		  2006-2-20
** Version:				  1.0
** Descriptions:		  The original version
**
**------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
** Version:
** Descriptions:
**
********************************************************************************************************/
//Includes
#include "system.h"
#include "LM75.h"
#include "oc_i2c.h"
#include  "sys/alt_irq.h"
#include "altera_avalon_pio_regs.h"

#define CONFIG        		0x00//Configuration Register is set to 0x00.
#define THYST        		75//Hysteresis Register is set to 75.
#define TOS	       			80//Over-temp Shutdown threshold Register 80

#define  I2C_BASE          I2C_MASTER_BASE //I2C?úo?μ??ùμ??·
#define  LM75_IRQ       	0xfff//LM75_OS_IRQ  //ó?LM75?àá??óμ??D??o?
#define  LM75_INT_BASE  	0xfff//LM75_OS_BASE //ó?LM75?àá??óμ?PIOμ??ùμ??·
#define  I2C_SPEED         (10000u)        //LM751¤×÷?ù?è￡o10kbps
static LM75_dev  dev;
static alt_u8 content[3];
#define  IRQCON       1          // External interrupt is connected to LM75_INT
                                 // This is bit mask of LM75_INT
                                 // user should modify it according to the real situation

static void LM75_ISR(void* context, alt_u32 id);

/*********************************************************************************************************
** Function name:     LM75_init
**
** Descriptions:      Initialize the I2C Open Core. The frequency of SCL is set as i2c_freq
**                    Interrupt will be enabled now.
**                    LM75_dev structure must be initialized before calling LM75_init()
**
** input parameters:  dev: a pointer to LM75 device  
**                    i2c_freq: work frequency of i2c                    
**						
** Returned value:	  negative,  fail
**                    zero or positive,   successfully
**         
** Used global variables:	None
** Calling modules:		    None
**
** Created by:				Zhou Shuwu
** Created Date:			2006/2/20
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
int LM75_Init(LM75_dev* dev, alt_u32 i2c_freq)
{
	alt_u32 prescale;
	
	/* Check if LM75_dev structure is initialized ? */
	if(dev->base == 0)
	{
		return -1;  // No, return error information
	}
	// initialize the I2C freq
	InitI2C(dev->base, i2c_freq, 0);
	
	// initialize the PIO(INT pin of LM75)
    prescale = IORD_ALTERA_AVALON_PIO_DIRECTION(dev->pio_base);
	prescale &= ~IRQCON;
	IOWR_ALTERA_AVALON_PIO_DIRECTION(dev->pio_base, prescale);
  /* Enable the PIO interrupt, which is connected to the INT pin of LM75 */
	IOWR_ALTERA_AVALON_PIO_IRQ_MASK(dev->pio_base, IRQCON);
	/* Clear edge capture register */  
	IOWR_ALTERA_AVALON_PIO_EDGE_CAP(dev->pio_base, 0);
	/* register the LM75 interrupt service routine */
	return alt_irq_register(dev->irq, dev, LM75_ISR);    
}

/*********************************************************************************************************
** Function name:     LM75_ReadReg
**
** Descriptions:      read register of LM75
**
** input parameters:	dev: a pointer to LM75 device  
**                      reg: offset of the target register
**                      content: the content of register will be stored here                    
**						
** Returned value:		negative,  fail
**                      zero or positive,   successfully
**         
** Used global variables:	dev, must be initialized
** Calling modules:		    None
**
** Created by:				Zhou Shuwu
** Created Date:			2006.2.20
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
int LM75_ReadReg (LM75_dev* dev, alt_u8 reg, alt_u8* content, alt_u16 num)
{
	
	if(dev->base == 0)
		return -1;      // invalid input parameters
		
    I2CRead(dev->base, dev->dev_addr, reg, content, num);

	return 0;
}
    
/*********************************************************************************************************
** Function name:     LM75_WriteReg
**
** Descriptions:      write register of LM75
**
** input parameters:	dev: a pointer to LM75 device  
**                      reg: offset of the target register
**                      content: the content of register will be stored here                    
**						
** Returned value:		negative,  fail
**                      zero or positive,   successfully
**         
** Used global variables:	dev, must be initialized
** Calling modules:		    None
**
** Created by:				Zhou Shuwu
** Created Date:			2006.2.20
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
int LM75_WriteReg(LM75_dev* dev, alt_u8 reg, alt_u8* content, alt_u16 num)
{
    if(dev->base == 0)
		return -1;      // invalid input parameters
		
    I2CWrite(dev->base, dev->dev_addr, reg, content, num);

	return 0;
}

/*********************************************************************************************************
** Function name:     LM75_ISR
**
** Descriptions:      Interrupt service routine for LM75 keydown event 
**
** input parameters:	context: a pointer passed to ISR  
**                    id: interrupt number               
**						
** Returned value:		None
**         
** Used global variables:	None
** Calling modules:		    None
**
** Created by:				Zhou Shuwu
** Created Date:			2006.2.20
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
static void LM75_ISR(void* context, alt_u32 id)
{
	
	LM75_dev* dev = (LM75_dev*) context;
    IOWR_ALTERA_AVALON_PIO_EDGE_CAP(dev->pio_base, 0);
    /* Notify that a interrupt occur    */
	dev->int_flag = INT_EVENT;
}

void TemperatureInit(void)
{
	dev.base = I2C_BASE;
    dev.dev_addr = LM75_ADDRESS;
    dev.irq  = LM75_IRQ;
    dev.pio_base = LM75_INT_BASE;
    dev.int_flag = NO_INT; 

	content[0] = CONFIG;
    LM75_WriteReg (&dev, LM75_CONFIG, content, 1);//CONFIG
    //tmp = (THYST*2) << 7;
    content[0] = 0x00;           // low significant data byte of THYST
    content[1] = THYST;          // high significant data byte of THYST
    LM75_WriteReg (&dev, LM75_THYST, content, 2);//THYST
    content[0] = 0x00;
	content[1] = TOS;
    LM75_WriteReg (&dev, LM75_TOS, content, 2);
}

int TempertureGet(alt_u8* temperBuf)
{
	return LM75_ReadReg (&dev, LM75_TEMP, temperBuf, 2);
}

/**********************end****************************************/