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I2C init error with the msp430f5529
von Alex A. (alextbg)

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Hey there, I have tried to make a program which can give me the data 
from my sensor SI7006-20A with I2C. The problem is, that when I run my 
project, nothing happens. I also used an Logic Analyzer and I saw that 
nothing happened. I really don't know what I could change. Maybe someone 
could help me, thanks a lot!


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#include "main.h"

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#include "msp430f5529.h"

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unsigned char add = 0x80; // serial number of the sensor

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unsigned char RHMeasure = 0xE5;

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unsigned char TEMpMeasure = 0xE0;

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double temp, rh;

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int help1, help2;

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void initI2C(){

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   UCB0CTL1 |= UCSWRST;

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  UCB1CTL0 = (1<<UCMST)|(1<<UCMODE0)|(1<<UCMODE1)|(1<<UCSYNC);

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  UCB1CTL1=(1<<UCSSEL1)|(1<<UCTR);

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  UCB1BR0 = 200;                               

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  UCB1BR1 = 0;  

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UCB1I2CSA = (add>>1);

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UCB1CTL1 &= ~(1<<UCSWRST);

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}

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void sendDataI2C(unsigned char data){

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   UCB1CTL1|= (1<<UCTXSTT); 

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   UCB1TXBUF = data;

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   while(UCB1IFG&(1<<UCTXIFG)==0x00);

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   UCB1CTL1 |= (1<<UCB1IFG);

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}

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unsigned char readDataI2C(){

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}

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unsigned int startRead(){

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  unsigned int data=0;

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    UCB1CTL1&=~(0x10);

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    UCB1CTL1 |=(1<<UCTXSTT);

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  //  while(UCB1CTL1 &(1<<UCTXSTT));

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    if(UCB1CTL1 &(1<<UCTXSTT)){

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      P1DIR |= BIT0;

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      P1OUT |= BIT0;

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    }else{

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      P4DIR |= BIT7;

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      P4OUT |= BIT7;

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    }

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   // while(UCB1STAT&(1<<UCBBUSY) > 0x00);

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    while(UCB1IFG&(1<<UCRXIFG)==0x00);

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    data = UCB1RXBUF*256;

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    while(UCB1IFG&(1<<UCRXIFG)==0x00);

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    data += UCB1RXBUF;

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    UCB1CTL1 |= (1<<UCTXNACK);

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    UCB1CTL1 |= (1<<UCTXSTP); 

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}

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void startWrite(unsigned char cmd){

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  UCB1CTL1|=(1<<UCTXSTT)|(0x10);

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  //UCB1CTL1 |= (1<<UCTXSTP); 

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  UCB1TXBUF = cmd;

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  while(UCB1IFG&(1<<UCTXIFG)==0x00);

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}

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int main(){

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    WDTCTL = WDTPW + WDTHOLD;                 

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    P4DIR |= BIT2;

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    P4DIR |= BIT1;

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    initI2C();

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    while(1){

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    startWrite(RHMeasure);

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    /* help2 = startRead();

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    rh = (help2*125)/65536-6;

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    startWrite(TEMpMeasure);

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    help1 = startRead();

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    temp = (help1*175.72)/65536-46.85;

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    */

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    __delay_cycles(100);

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    }

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}


  


  



  

  
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    Re: I2C init error with the msp430f5529
  


  

    

      von
      
        neuer PIC Freund (Guest)
      
      


      
    


    

      
    

    

    

  
  


  

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Hi

1
UCB1CTL1=(1<<UCSSEL1)|(1<<UCTR);


translates to

1
UCB1CTL1=(1<<0x80)|(1<<0x10);


which leads to a warning.

Dont use avr-stylish shift operations. Use instead

1
UCB1CTL1 = UCSSEL1 | UCTR;


Take the compiler warnings serious.

  


  




  

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    Re: I2C init error with the msp430f5529
  


  

    

      von
      
        Alex A.
        (alextbg)
        
      
      


      
    


    

      
    

    

    

  
  


  

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Thanks for your answer, but unfortunately nothing changed. I still see 
nothing on my Logic Analyzer

  


  




  

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    Re: I2C init error with the msp430f5529
  


  

    

      von
      
        stefanus (Guest)
      
      


      
    


    

      
    

    

    

  
  


  

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The only functiopn that you call from main() is startWrite(). Can that 
work without a prior call to initI2C()?

  


  




  

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    Re: I2C init error with the msp430f5529
  


  

    

      von
      
        Lothar M.
            (Company: Titel)
        (lkmiller)
        (Moderator)
      
      


      
    


    

      
    

    

    

  
  


  

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Alex A. wrote:
> but unfortunately nothing changed.
Same warnings/errors after compiling?
Show the changed code pls!

stefanus wrote:
> The only functiopn that you call from main() is startWrite(). Can that
> work without a prior call to initI2C()?
Try once more... ;-)

  


  



  

  
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    Re: I2C init error with the msp430f5529
  


  

    

      von
      
        Alex A.
        (alextbg)
        
      
      


      
    


    

      
    

    

    

  
  


  

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I have the init above the while and I have just warnings of missing 
return statement but I ignored this because i just want to check the 
init. And it isn't working...

1
#include "main.h"

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#include "msp430f5529.h"

3
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unsigned char add = 0x80;

5
unsigned char RHMeasure = 0xE5;

6
unsigned char TEMpMeasure = 0xE0;

7
8
double temp, rh;

9
int help1, help2;

10
11
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void initI2C(){

14
   UCB0CTL1 |= UCSWRST;

15
  UCB1CTL0 = UCMST | UCMODE0 | UCMODE1 | UCSYNC; //MasterMode   I2C Mode

16
  UCB1CTL1= UCSSEL1 | UCTR;

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  UCB1BR0 = 200;                               //fSCL = SMCLK/(40+0*256)

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  UCB1BR1 = 0;  

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UCB1I2CSA = (add>>1);

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UCB1CTL1 &= ~UCSWRST;

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}

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void sendDataI2C(unsigned char data){

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   UCB1CTL1|= UCTXSTT; 

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   UCB1TXBUF = data;

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   while((UCB1IFG & UCTXIFG)==0x00);

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   UCB1CTL1 |= UCB1IFG;

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}

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unsigned char readDataI2C(){

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}

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unsigned int startRead(){

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  unsigned int data=0;

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    UCB1CTL1 &=~ (0x10);

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    UCB1CTL1 |= UCTXSTT;

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  //  while(UCB1CTL1 & UCTXSTT);

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    if(UCB1CTL1 & UCTXSTT){

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      P1DIR |= BIT0;

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      P1OUT |= BIT0;

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    }else{

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      P4DIR |= BIT7;

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      P4OUT |= BIT7;

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    }

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   // while((UCB1STAT & UCBBUSY) > 0x00);

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    while((UCB1IFG & UCRXIFG) == 0x00);

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    data = UCB1RXBUF*256;

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    //ACK automatisch vermutlich 

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    while((UCB1IFG & UCRXIFG) == 0x00);

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    data += UCB1RXBUF;

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    UCB1CTL1 |= UCTXNACK;

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    UCB1CTL1 |= UCTXSTP; 

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}

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void startWrite(unsigned char cmd){

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  UCB1CTL1 |= UCTXSTT | (0x10);

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  //UCB1CTL1 |= UCTXSTP; 

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  UCB1TXBUF = cmd;

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  while((UCB1IFG & UCTXIFG) == 0x00);

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}

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int main(){

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    WDTCTL = WDTPW + WDTHOLD;

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    P4DIR |= BIT2;

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    P4DIR |= BIT1;

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    while(1){

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    initI2C();

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    startWrite(RHMeasure);

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    /* help2 = startRead();

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    rh = (help2*125)/65536-6;

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    startWrite(TEMpMeasure);

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    help1 = startRead();

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    temp = (help1*175.72)/65536-46.85;

93
    */

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    __delay_cycles(100);

95
   

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    }

97
}


  


  




  

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    Re: I2C init error with the msp430f5529
  


  

    

      von
      
        Clemens L.
        (c_l)
        
      
      


      
    


    

      
    

    

    

  
  


  

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Alex A. wrote:
>    UCB0CTL1 |= UCSWRST;

This resets the wrong module; use UCB1CTL1.

> UCB1CTL1= UCSSEL1 | UCTR;

This clears the reset bit, and the following baud rate setting is not 
applied.

> UCB1CTL1 |= UCTXSTT | (0x10);

The 0x10 is the UCTXNACK bit. What's it doing here?

> UCB1TXBUF = cmd;

You can do that only after you have checked that the buffer is free 
(TXIFG).

> P4DIR |= BIT2;
> P4DIR |= BIT1;

This sets these two pins as GPIO outputs. To connect these pins to the 
I²C module instead, set the bits in P4SEL.


I would recommend to begin with a working example like 
MSP430F55xx_uscib0_i2c_08.c.

  


  




  

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