求教关于MLX90614红外测温的STM32FZET6驱动程序问题

孤久则安 · 发表于 2018-2-25 23:48:20

使用STM32F103ZET6驱动MLX90614红外测温模块，使用TFTLCD显示，但是测出的温度值一直不变，求教各位大佬，附程序代码主函数：
int main(void)
{
u16 adcx;
float temp;
delay_init();            //Ñóê±oˉêy3õê¼»ˉ
uart_init(9600);      //′®¿ú3õê¼»ˉÎa9600
LED_Init();       //3õê¼»ˉóëLEDá¬½óμÄó2¼t½ó¿ú
LCD_Init();
   SMBus_Init();
LCD_ShowString(60,150,200,16,16,"Temp: .  C");
while(1)
{
temp=SMBus_ReadTemp();

adcx=temp;
LCD_ShowxNum(60+40,150,adcx,3,16,0);//ÏÔê¾μçÑ1Öμ
temp-=adcx;
temp*=100;
LCD_ShowxNum(60+40+30,150,temp,2,16,0X80);
LED0=!LED0;
delay_ms(250);
}
}

头文件：

/*******************************************************************************
* 文件名 : mlx90614.h
* 作  者 :
* 版  本 :
* 日  期 : 2013-08-07
* 描  述 : mlx90614函数
*******************************************************************************/

/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __MLX90614_H
#define __MLX90614_H

/* Includes ------------------------------------------------------------------*/
#include "stm32f10x.h"
/* Exported types ------------------------------------------------------------*/
/* Exported variables --------------------------------------------------------*/
/* Exported constants --------------------------------------------------------*/
/* Exported macro ------------------------------------------------------------*/
/* Exported functions ------------------------------------------------------- */
void SMBus_StartBit(void);
void SMBus_StopBit(void);
void SMBus_SendBit(u8);
u8 SMBus_SendByte(u8);
u8 SMBus_ReceiveBit(void);
u8 SMBus_ReceiveByte(u8);
void SMBus_Delay(u16);
void SMBus_Init(void);
u16 SMBus_ReadMemory(u8, u8);
u8 PEC_Calculation(u8*);
float SMBus_ReadTemp(void); //获取温度值

#endif

/*********************************END OF FILE*********************************/

C文件：
/*******************************************************************************
* 文件名 : mlx90614.c
* 作  者 :
* 版  本 :
* 日  期 : 2013-08-07
* 描  述 : mlx90614函数
PB6：SCL
PB7：SDA
在主函数中先初始化SMBus_Init();
需要读取温度就调用temp=SMBus_ReadTemp();  //读取温度，temp是浮点数，转整数：i=ceil(temp);
*******************************************************************************/

/* Includes ------------------------------------------------------------------*/

#include "mlx90614.h"

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define ACK    0 //应答
#define NACK 1 //无应答
#define SA 0x00 //Slave address 单个MLX90614时地址为0x00,多个时地址默认为0x5a
#define RAM_ACCESS 0x00 //RAM access command RAM存取命令
#define EEPROM_ACCESS 0x20 //EEPROM access command EEPROM存取命令
#define RAM_TOBJ1 0x07 //To1 address in the eeprom 目标1温度,检测到的红外温度 -70.01 ~ 382.19度

#define SMBUS_PORT GPIOE    //PE端口(端口和下面的两个针脚可自定义)
#define SMBUS_SCK GPIO_Pin_0 //PE0：SCL
#define SMBUS_SDA GPIO_Pin_1 //PE1：SDA

#define RCC_APB2Periph_SMBUS_PORT RCC_APB2Periph_GPIOE

#define SMBUS_SCK_H()       SMBUS_PORT->BSRR = SMBUS_SCK //置高电平
#define SMBUS_SCK_L()       SMBUS_PORT->BRR = SMBUS_SCK  //置低电平
#define SMBUS_SDA_H()       SMBUS_PORT->BSRR = SMBUS_SDA
#define SMBUS_SDA_L()       SMBUS_PORT->BRR = SMBUS_SDA

#define SMBUS_SDA_PIN()       SMBUS_PORT->IDR & SMBUS_SDA //读取引脚电平

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/

/*******************************************************************************
* Function Name  : SMBus_StartBit
* Description : Generate START condition on SMBus
* Input       : None
* Output       : None
* Return       : None
*******************************************************************************/
void SMBus_StartBit(void)
{
SMBUS_SDA_H(); // Set SDA line
SMBus_Delay(5);       // Wait a few microseconds
SMBUS_SCK_H(); // Set SCL line
SMBus_Delay(5);       // Generate bus free time between Stop
SMBUS_SDA_L(); // Clear SDA line
SMBus_Delay(5);       // Hold time after (Repeated) Start
// Condition. After this period, the first clock is generated.
//(Thd:sta=4.0us min)在SCK=1时，检测到SDA由1到0表示通信开始（下降沿）
SMBUS_SCK_L();       // Clear SCL line
SMBus_Delay(5);       // Wait a few microseconds
}

/*******************************************************************************
* Function Name  : SMBus_StopBit
* Description : Generate STOP condition on SMBus
* Input       : None
* Output       : None
* Return       : None
*******************************************************************************/
void SMBus_StopBit(void)
{
SMBUS_SCK_L(); // Clear SCL line
SMBus_Delay(5);       // Wait a few microseconds
SMBUS_SDA_L(); // Clear SDA line
SMBus_Delay(5);       // Wait a few microseconds
SMBUS_SCK_H(); // Set SCL line
SMBus_Delay(5);       // Stop condition setup time(Tsu:sto=4.0us min)
SMBUS_SDA_H(); // Set SDA line在SCK=1时，检测到SDA由0到1表示通信结束（上升沿）
}

/*******************************************************************************
* Function Name  : SMBus_SendByte
* Description : Send a byte on SMBus
* Input       : Tx_buffer
* Output       : None
* Return       : None
*******************************************************************************/
u8 SMBus_SendByte(u8 Tx_buffer)
{
u8 Bit_counter;
u8 Ack_bit;
u8 bit_out;

for(Bit_counter=8; Bit_counter; Bit_counter--)
{
      if (Tx_buffer&0x80)
      {
         bit_out=1; // If the current bit of Tx_buffer is 1 set bit_out
      }
      else
      {
         bit_out=0;  // else clear bit_out
      }
      SMBus_SendBit(bit_out); // Send the current bit on SDA
      Tx_buffer<<=1; // Get next bit for checking
}

Ack_bit=SMBus_ReceiveBit(); // Get acknowledgment bit
return Ack_bit;
}

/*******************************************************************************
* Function Name  : SMBus_SendBit
* Description : Send a bit on SMBus 82.5kHz
* Input       : bit_out
* Output       : None
* Return       : None
*******************************************************************************/
void SMBus_SendBit(u8 bit_out)
{
if(bit_out==0)
{
      SMBUS_SDA_L();
}
else
{
      SMBUS_SDA_H();
}
SMBus_Delay(2); // Tsu:dat = 250ns minimum
SMBUS_SCK_H(); // Set SCL line
SMBus_Delay(6); // High Level of Clock Pulse
SMBUS_SCK_L(); // Clear SCL line
SMBus_Delay(3); // Low Level of Clock Pulse
// SMBUS_SDA_H();       // Master release SDA line ,
return;
}

/*******************************************************************************
* Function Name  : SMBus_ReceiveBit
* Description : Receive a bit on SMBus
* Input       : None
* Output       : None
* Return       : Ack_bit
*******************************************************************************/
u8 SMBus_ReceiveBit(void)
{
u8 Ack_bit;

SMBUS_SDA_H();       //引脚靠外部电阻上拉，当作输入
SMBus_Delay(2); // High Level of Clock Pulse
SMBUS_SCK_H(); // Set SCL line
SMBus_Delay(5); // High Level of Clock Pulse
if (SMBUS_SDA_PIN())
{
      Ack_bit=1;
}
else
{
      Ack_bit=0;
}
SMBUS_SCK_L(); // Clear SCL line
SMBus_Delay(3); // Low Level of Clock Pulse

return Ack_bit;
}

/*******************************************************************************
* Function Name  : SMBus_ReceiveByte
* Description : Receive a byte on SMBus
* Input       : ack_nack
* Output       : None
* Return       : RX_buffer
*******************************************************************************/
u8 SMBus_ReceiveByte(u8 ack_nack)
{
u8 RX_buffer;
u8 Bit_Counter;

for(Bit_Counter=8; Bit_Counter; Bit_Counter--)
{
      if(SMBus_ReceiveBit()) // Get a bit from the SDA line
      {
         RX_buffer <<= 1; // If the bit is HIGH save 1  in RX_buffer
         RX_buffer |=0x01;
      }
      else
      {
         RX_buffer <<= 1; // If the bit is LOW save 0 in RX_buffer
         RX_buffer &=0xfe;
      }
}
SMBus_SendBit(ack_nack); // Sends acknowledgment bit
return RX_buffer;
}

/*******************************************************************************
* Function Name  : SMBus_Delay
* Description : 延时  一次循环约1us
* Input       : time
* Output       : None
* Return       : None
*******************************************************************************/
void SMBus_Delay(u16 time)
{
u16 i, j;
for (i=0; i<4; i++)
{
      for (j=0; j<time; j++);
}
}

/*******************************************************************************
* Function Name  : SMBus_Init
* Description : SMBus初始化
* Input       : None
* Output       : None
* Return       : None
*******************************************************************************/
void SMBus_Init()
{
GPIO_InitTypeDef GPIO_InitStructure;

/* Enable SMBUS_PORT clocks */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SMBUS_PORT, ENABLE);

/*配置SMBUS_SCK、SMBUS_SDA为集电极开漏输出*/
GPIO_InitStructure.GPIO_Pin = SMBUS_SCK | SMBUS_SDA;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(SMBUS_PORT, &GPIO_InitStructure);

SMBUS_SCK_H();
SMBUS_SDA_H();
}

/*******************************************************************************
* Function Name  : SMBus_ReadMemory
* Description : READ DATA FROM RAM/EEPROM
* Input       : slaveAddress, command
* Output       : None
* Return       : Data
*******************************************************************************/
u16 SMBus_ReadMemory(u8 slaveAddress, u8 command)
{
u16 data; // Data storage (DataH

ataL)
u8 Pec; // PEC byte storage
u8 DataL=0; // Low data byte storage
u8 DataH=0; // High data byte storage
u8 arr[6]; // Buffer for the sent bytes
u8 PecReg; // Calculated PEC byte storage
u8 ErrorCounter; // Defines the number of the attempts for communication with MLX90614

ErrorCounter=0x00; // Initialising of ErrorCounter
slaveAddress <<= 1; //2-7位表示从机地址

do
{
repeat:
      SMBus_StopBit();       //If slave send NACK stop comunication
      --ErrorCounter;       //Pre-decrement ErrorCounter
      if(!ErrorCounter)       //ErrorCounter=0?
      {
         break;       //Yes,go out from do-while{}
      }

      SMBus_StartBit(); //Start condition
      if(SMBus_SendByte(slaveAddress))//Send SlaveAddress 最低位Wr=0表示接下来写命令
      {
         goto repeat;       //Repeat comunication again
      }
      if(SMBus_SendByte(command))       //Send command
      {
         goto repeat;         //Repeat comunication again
      }

      SMBus_StartBit(); //Repeated Start condition
      if(SMBus_SendByte(slaveAddress+1)) //Send SlaveAddress 最低位Rd=1表示接下来读数据
      {
         goto repeat;          //Repeat comunication again
      }

      DataL = SMBus_ReceiveByte(ACK); //Read low data,master must send ACK
      DataH = SMBus_ReceiveByte(ACK); //Read high data,master must send ACK
      Pec = SMBus_ReceiveByte(NACK); //Read PEC byte, master must send NACK
      SMBus_StopBit(); //Stop condition

      arr[5] = slaveAddress; //
      arr[4] = command; //
      arr[3] = slaveAddress+1; //Load array arr
      arr[2] = DataL; //
      arr[1] = DataH; //
      arr[0] = 0; //
      PecReg=PEC_Calculation(arr);//Calculate CRC
}
while(PecReg != Pec); //If received and calculated CRC are equal go out from do-while{}

data = (DataH<<8) | DataL; //data=DataH

ataL
return data;
}

/*******************************************************************************
* Function Name  : PEC_calculation
* Description : Calculates the PEC of received bytes
* Input       : pec[]
* Output       : None
* Return       : pec[0]-this byte contains calculated crc value
*******************************************************************************/
u8 PEC_Calculation(u8 pec[])
{
u8 crc[6];
u8 BitPosition=47;
u8 shift;
u8 i;
u8 j;
u8 temp;

do
{
      /*Load pattern value 0x000000000107*/
      crc[5]=0;
      crc[4]=0;
      crc[3]=0;
      crc[2]=0;
      crc[1]=0x01;
      crc[0]=0x07;

      /*Set maximum bit position at 47 ( six bytes byte5...byte0,MSbit=47)*/
      BitPosition=47;

      /*Set shift position at 0*/
      shift=0;

      /*Find first "1" in the transmited message beginning from the MSByte byte5*/
      i=5;
      j=0;
      while((pec&(0x80>>j))==0 && i>0)
      {
         BitPosition--;
         if(j<7)
         {
            j++;
         }
         else
         {
            j=0x00;
            i--;
         }
      }/*End of while */

      /*Get shift value for pattern value*/
      shift=BitPosition-8;

      /*Shift pattern value */
      while(shift)
      {
         for(i=5; i<0xFF; i--)
         {
            if((crc[i-1]&0x80) && (i>0))
            {
                  temp=1;
            }
            else
            {
                  temp=0;
            }
            crc<<=1;
            crc+=temp;
         }/*End of for*/
         shift--;
      }/*End of while*/

      /*Exclusive OR between pec and crc*/
      for(i=0; i<=5; i++)
      {
         pec ^=crc;
      }/*End of for*/
}
while(BitPosition>8); /*End of do-while*/

return pec[0];
}

/*******************************************************************************
* Function Name  : SMBus_ReadTemp
* Description : Calculate and return the temperature
* Input       : None
* Output       : None
* Return       : SMBus_ReadMemory(0x00, 0x07)*0.02-273.15
*******************************************************************************/
float SMBus_ReadTemp(void)
{
float temp;
temp = SMBus_ReadMemory(SA, RAM_ACCESS|RAM_TOBJ1)*0.02-273.15;
return temp;
}

/*********************************END OF FILE*********************************/