MSP430f149+mlx90614 测温求帮助！！！

只看该作者 · 2015-3-24 14:07

本人毕设用msp430f149+mlx90614想做个测温度的装置
但不知为何在实验板上测试了两周也无法得到mlx90614的ack
还请各位大神帮助本人算430半小白
情况供电无问题 90614 SCL SDA引脚均接了上拉电阻然后
直接连到430引脚上本人想用SMbus通信
还请各位大神帮助！！！
下面是程序：#include  <msp430x14x.h>
void Delay(unsigned int n);
void start_bit();
void stop_bit();
void send_bit(unsigned char bit_out);
unsigned char receive_bit();
unsigned char slave_ack();
void TX_byte(unsigned char TX_buffer);
unsigned char RX_byte(unsigned char ack_nack);
unsigned char PEC_cal(unsigned char pec[],int n);
unsigned long int MEM_READ( unsigned char slave_addR, unsigned char cmdR );
void CALTEMP(unsigned long int TEMP);

void mlx90614_SCL_0() { P1OUT &= ~0x02;}  // define P1.1 ---> SCL
void mlx90614_SCL_1() { P1OUT |= 0x02;}

void mlx90614_SDA_0() { P1OUT &= ~0x04;}  // define P1.2 ---> SDA
void mlx90614_SDA_1() { P1OUT |= 0x04;}

#define _SDA_OUTPUT P1DIR |=0x04; //Set SDA as Output
#define _SDA_INPUT P1DIR &=~0x04; //Set SDA as Input

#define SDA ((P1IN & BIT2)>>1) //define input pin

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;       // Stop Watch dog timer
BCSCTL1 = RSEL0 + RSEL1 + RSEL2;       // XT2on, max RSEL
DCOCTL = DCO0 + DCO1 + DCO2;             // Max DCO

P1DIR = 0xFF;    // All P1.x outputs
  P1OUT = 0;       // All P1.x reset

while(1)                         // While 1 is equal to 1 (forever)
  {
unsigned long int DATA;

DATA=MEM_READ(0x5a,0x07);
CALTEMP(DATA);

  }
}

void Delay(unsigned int n)
{
  unsigned int i;
  for(i=0;i<n;i++)
  _NOP();
}

//----------------------------------------------------------------------------------------------------------------------------------------//
//Name: start_bit
//----------------------------------------------------------------------------------------------------------------------------------------//
void start_bit()
{
  _SDA_OUTPUT; //Set SDA as output
  Delay(5);
  mlx90614_SDA_1();
  //Delay(30);
  mlx90614_SCL_1();

  Delay(30);
  mlx90614_SDA_0();
  Delay(30);
  mlx90614_SCL_0();
  Delay(30);

}

//----------------------------------------------------------------------------------------------------------------------------------------//
//Name: stop_bit
//----------------------------------------------------------------------------------------------------------------------------------------//
void stop_bit()
{
  _SDA_OUTPUT; //Set SDA as output
  Delay(5);
  //mlx90614_SCL_0();
  mlx90614_SDA_0();
  Delay(30);
  mlx90614_SCL_1();
  Delay(30);
  mlx90614_SDA_1();
}

//----------------------------------------------------------------------------------------------------------------------------------------//
//Name: send_bit
//----------------------------------------------------------------------------------------------------------------------------------------//
void send_bit(unsigned char bit_out)
{
  _SDA_OUTPUT; //Set SDA as output
  Delay(5);
  if(bit_out==0) {mlx90614_SDA_0();}else{mlx90614_SDA_1();}
  Delay(5);
  mlx90614_SCL_1();
  Delay(30);
  mlx90614_SCL_0();
  Delay(30);
}

//----------------------------------------------------------------------------------------------------------------------------------------//
//Name: receive_bit
//----------------------------------------------------------------------------------------------------------------------------------------//
unsigned char receive_bit()
{
  unsigned char bit_in;
  _SDA_INPUT; //Set SDA as input
  Delay(5);
  mlx90614_SCL_1();
  Delay(5);
  if(SDA==1){bit_in=1;}else{bit_in=0;}
  Delay(10);
  mlx90614_SCL_0();
  Delay(30);
  return bit_in;
}

//----------------------------------------------------------------------------------------------------------------------------------------//
//Name: slave_ack
//1 - ACK
//0 -NACK
//----------------------------------------------------------------------------------------------------------------------------------------//
unsigned char slave_ack()
{
  unsigned char ack;
  ack=0;
  _SDA_INPUT; //Set SDA as input
  Delay(5);
  mlx90614_SCL_1();
  Delay(10);
  if(SDA==0){ack=0;}else{ack=1;}
  Delay(10);
  mlx90614_SCL_0();
  Delay(30);
  return ack;
}

//----------------------------------------------------------------------------------------------------------------------------------------//
//Name: TX_byte
//----------------------------------------------------------------------------------------------------------------------------------------//
void TX_byte(unsigned char TX_buffer)
{
  unsigned char Bit_counter;
  unsigned char bit_out;
  for(Bit_counter=8;Bit_counter;Bit_counter--)
  {
if(TX_buffer&0x80){bit_out=1;}else{bit_out=0;}
send_bit(bit_out); //Send the current bit on SMBus
TX_buffer<<=1; //Get next bit to check
  }
}

//----------------------------------------------------------------------------------------------------------------------------------------//
//Name: RX_byte
//Parameters: unsigned char ack_nack (acknowledgment bit)
//0 - Master device sends ACK
//1 - Master device sends NACK
//----------------------------------------------------------------------------------------------------------------------------------------//
unsigned char RX_byte(unsigned char ack_nack)
{
unsigned char RX_buffer;
unsigned char Bit_counter;
for(Bit_counter=8;Bit_counter;Bit_counter--)
{
   if(receive_bit()==1) //Read a bit from the SDA line
   {
   RX_buffer<<=1; //If the bit is HIGH save 1 in RX_buffer
   RX_buffer|=0x01;
   }
   else //If the bit is LOW save 0 in RX_buffer
   {
   RX_buffer<<=1;
   RX_buffer&=0xfe;
   }
}
send_bit(ack_nack); //Sends acknowledgment bit
return RX_buffer;
}

//----------------------------------------------------------------------------------------------------------------------------------------//
//CALCULATE THE PEC PACKET
//----------------------------------------------------------------------------------------------------------------------------------------//
unsigned char PEC_cal(unsigned char pec[],int n)
{
unsigned char crc[6];
unsigned char Bitposition=47;
unsigned char shift;
unsigned char i;
unsigned char j;
unsigned char temp;
  do{
crc[5]=0; //Load CRC value 0x000000000107
crc[4]=0;
crc[3]=0;
crc[2]=0;
crc[1]=0x01;
crc[0]=0x07;
Bitposition=47; //Set maximum bit position at 47
shift=0;       //Find first 1 in the transmitted bytes
i=5; //Set highest index (package byte index)
j=0; //Byte bit index, from lowest
while((pec[i]&(0x80>>j))==0 && (i>0))
{
   Bitposition--;
   if(j<7){ j++;}
   else {j=0x00;i--;}
}//the position of highest "1" bit in Bitposition is calculated
shift=Bitposition-8; //Get shift value for CRC value

while(shift)
{
   for(i=5;i<0xFF;i--)
   {
   if((crc[i-1]&0x80) && (i>0)) //Check if the MSB of the byte lower is "1"
      { //Yes - current byte + 1
      temp=1; //No - current byte + 0
      } //So that "1" can shift between bytes
   else { temp=0;}
   crc[i]<<=1;
   crc[i]+=temp;
   }
shift--;
}
//Exclusive OR between pec and crc
for(i=0;i<=5;i++) { pec[i]^=crc[i]; }
}
while(Bitposition>8);
return pec[0];
}

//----------------------------------------------------------------------------------------------------------------------------------------//
//READ DATA FROM RAM/EEPROM
//----------------------------------------------------------------------------------------------------------------------------------------//
unsigned long int MEM_READ(unsigned char slave_addR, unsigned char cmdR)
{
  unsigned char DataL; //
  unsigned char DataH; //Data packets from MLX90614
  unsigned char PEC; //
  unsigned long int Data; //Register value returned from MLX90614
  unsigned char Pecreg; //Calculated PEC byte storage
  unsigned char arr[6]; //Buffer for the sent bytes
  unsigned char ack_nack;
  unsigned char SLA;
  SLA=(slave_addR<<1);
begin:
  start_bit(); //Send start bit
  TX_byte(SLA); //Send slave address, write
  if(slave_ack()==0){stop_bit();goto begin;} //Send command
  TX_byte(cmdR);
  if(slave_ack()==0){stop_bit();goto begin;}//Send Repeated start bit
  start_bit(); //Send slave address, read
  TX_byte(SLA+1);
  if(slave_ack()==0){stop_bit();goto begin;}
  DataL=RX_byte(0); //
  //Read two bytes data
  DataH=RX_byte(0); //
  PEC=RX_byte(ack_nack); //Read PEC from MLX90614
  if(ack_nack==1) //Master sends ack or nack
  //This depends on the pec calculation,
  //if the PEC is not correct, send nack and goto begin
  {stop_bit();goto begin;} //Send stop bit
  stop_bit();
  arr[5]=(SLA);
  arr[4]=cmdR;
  arr[3]=(SLA+1);
  arr[2]=DataL;
  arr[1]=DataH;
  arr[0]=0;
  Pecreg=PEC_cal(arr,6); //Calculate CRC
  if(PEC==Pecreg){ ack_nack=0;}
  else{ ack_nack=1;}
  Data=(DataH*256)+DataL;
  return Data;
}

//---------------------------------------
//Name: CALTEMP
//Temperature data is T=(Data)*0.02-273.15
//---------------------------------------
void CALTEMP(unsigned long int TEMP)
{
unsigned long int T;
unsigned int a,b;
T=TEMP*2;
if(T>=27315)
{
   T=T-27315;
   a=T/100;
   b=T-a*100;
   if(a>=100){A4=a/100;a=a%100;A5=a/10;a=a%10;A6=a;}
   else if(a>=10){A4=0;A5=a/10;a=a%10;A6=a;}
   else {A4=0;A5=0;A6=a;}
   if(b>=10){A7=b/10;b=b%10;A8=b;}
   else{A7=0;A8=b;}
}
else
{
   T=27315-T;
   a=T/100;
   b=T-a*100;
   A4=9;
   if(a>=10){A5=a/10;a=a%10;A6=a;}
   else{A5=0;A6=a;}
   if(b>=10){ A7=b/10;b=b%10;A8=b;}
   else{A7=0;A8=b;}
}
}

显示等程序被我剪掉了现在接收不到ack Data一直等于0
我自己怀疑是延时和时钟设置问题但不知如何修改
还请各位前辈帮帮我我先提前谢谢各位了。。。