Ask the Expert: Fredy Klammsteiner - Sensor Application Expert

Mr. Klammsteiner,

I need a small pressure sensor to use internally on a gas pressure system. Suggestions?

Due to the sealed system, how could I pass the data from the sensor to an external system?

E

Dear Eavesdropper

We are a producer of thin film elements for temperature, humidity, flow and conductivity. We don't produce any pressure sensors. But Endress + Hauser produces pressure sensors for gas and liquid applications:

http://www.uk.endress.com/#products/~products-instruments-pressure-measurement

I'me sure you will get help there.

Best regards

Fredy Klammsteiner

Hi Fredy,

I'm trying to measure a low airflow - between 0 and 5m/s.

Can you suggest the correct sensor and also some links to some microcontroller software to analyse sensor output?

Alternatively, is there a bit more applications info available to the analog circuitry on the IST website?

Thanks.

i have msp430fg4618 controller. i want to read hyt-221 sensor useing i2c.i interfaced sensor and useing IAR develop following code but its not work.NACK is coming from sensor.

//******************************************************************************

//   MSP430xG461x Demo - USCI_B0 I2C Master TX multiple bytes to MSP430 Slave

//

//   Description: This demo connects two MSP430's via the I2C bus. The master

//   transmits to the slave. This is the master code. It continuously

//   transmits an array of data and demonstrates how to implement an I2C

//   master transmitter sending multiple bytes using the USCI_B0 TX interrupt.

//   ACLK = 32kHz, MCLK = SMCLK = TACLK = BRCLK = 1MHz

//

//                                 /|\  /|\

//                MSP430xG461x     10k  10k    MSP430xG461x

//                    slave         |    |        master

//              -----------------   |    |  -----------------

//            -|XIN  P3.1/UCB0SDA|<-|---+->|P3.1/UCB0SDA  XIN|-

//       32kHz |                 |  |      |                 | 32kHz

//            -|XOUT             |  |      |             XOUT|-

//             |     P3.2/UCB0SCL|<-+----->|P3.2/UCB0SCL     |

//             |                 |         |                 |

//

//   Andreas Dannenberg/ M. Mitchell

//   Texas Instruments Inc.

//   October 2006

//   Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.41A

//******************************************************************************

#include "msp430xG46x.h"

volatile unsigned char k,d,t,*prxdata,s,txdatactr;                    

volatile unsigned char data,rxdatactr,rxdata[5]={0,0,0,0,0},sdatactr;

int i;

void delay(int i)

{

  while(i!=0)

  {

    i--;

  }

}

void main(void)

{

  WDTCTL = WDTPW + WDTHOLD;

delay(60000);

  P3SEL |= 0x06;

  P2SEL |=0x00;

  P5SEL =0x00;

  P5DIR =0x02;

  P2DIR |= 0x06;

  P5OUT=0x00;

   UCB0CTL1 |= UCSWRST;                     

  UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC;    

  UCB0CTL1 = UCSSEL_2 + UCSWRST;           

  UCB0BR0 = 10;                           

  UCB0BR1 = 0;

  UCB0I2CSA = 0x29;

UCB0I2CIE =0x09;                        

  UCB0CTL1 &= ~UCSWRST;    

  P5OUT |=0x02;                                  

  while (1)

  {

     P2OUT=0x04;

    delay(60000);

    P2OUT=0x00;

    delay(60000);

    txdatactr=1;

    IE2 |= UCB0TXIE;

    k=1;

    __bis_SR_register(GIE);

    UCB0CTL1 |= UCTR + UCTXSTT;           

      while(k);    

      while (UCB0CTL1 & UCTXSTP);  

    P2OUT=0x04;

    delay(60000);

    P2OUT=0x00;

    delay(60000);

    t=1;

    rxdatactr=3;

    prxdata= &rxdata[0];

    IE2 |= UCB0RXIE;

     UCB0CTL1 &= ~UCTR;        

    UCB0CTL1 |= UCTXSTT;

    __bis_SR_register(CPUOFF + GIE);

     while (UCB0CTL1 & UCTXSTP);

//UCB0CTL1 &= ~UCTXSTP;

  }

}

//------------------------------------------------------------------------------

// The USCIAB0TX_ISR is structured such that it can be used to transmit any

// number of bytes by pre-loading TXByteCtr with the byte count. Also, TXData

// points to the next byte to transmit.

//------------------------------------------------------------------------------

#pragma vector = USCIAB0TX_VECTOR

__interrupt void USCIAB0TX_ISR(void)

{

  if(k==1)

  {

            if(txdatactr)

          {

            UCB0TXBUF=0x28;

            txdatactr--;

          }

        else

          {

               UCB0CTL1 |= UCTXSTP;

               //UCB0CTL1 &= ~UCTXSTT;

               IFG2 &= ~UCB0TXIFG;

               IE2 &= ~UCB0TXIE;

               k=0;

                //__bic_SR_register_on_exit(CPUOFF);

          }

  }

   if(t==1)

  {

  if (rxdatactr)                           

  {

   *prxdata=UCB0RXBUF;

   if((IFG2 & UCB0RXIFG)==0)

    {

      P5OUT |=0x02;

    }

   if(rxdatactr==1)

   {

    UCB0CTL1 |= UCTXSTP;

   }

    rxdatactr--;

    prxdata++;

  }

  else

  {

    *prxdata=UCB0RXBUF;

    // UCB0CTL1 |= UCTXSTP;          

   IE2 &= ~UCB0RXIE;

    t=0;

    __bic_SR_register_on_exit(CPUOFF);     

  }

  }

}

#pragma vector=USCIAB0RX_VECTOR

__interrupt void USCIA0RX_ISR (void)

{

  if((UCB0STAT && UCNACKIFG)==1)

  {

    P5OUT =0x00;

    UCB0STAT &=~UCNACKIFG;

  }

  if((UCB0STAT & UCALIFG)==1)

  {

    P5OUT |=0x00;

  }

}         

so plz help me///////

Dear karan patel

Could you please send this request to my email address fredy.klammsteiner@ist-ag.com. I will forward it to our responsible person at IST AG.

Thanks and best regards

Fredy Klammsteiner