Problem in MSP430 communicating with Accelerometer(MMA7456L) on I2C bus

Hi,

"But when i am waiting for interrupt from accelerometer to msp on GPIO pin(port2.1), interrupt flag is not getting set."

can u pls tell more clear about how, exactly u set the msp GPIO pin to get the interrupt/

if possible pls paste the code

Hi dileep,

are you shure your settings for P2.1 were correct? The code below is taken from a TI example for this sub-series, so you can ignore the LPM4 code.

#include  <msp430x47x4.h>

void main(void)
{

  WDTCTL = WDTPW+WDTHOLD;                   // Stop WDT
  P5DIR |= BIT1;                           // P5.1 output
  P1IE |= BIT4;                            // P1.4 Interrupt enabled
  P1IES |= BIT4;                           // P1.4 hi/low edge
  P1IFG &= ~BIT4;                          // P1.4 IFG Cleared

  _BIS_SR(LPM4_bits + GIE);                 // LPM4, enable interrupts
}

// Port 1 interrupt service routine
#pragma vector=PORT1_VECTOR
__interrupt void Port1_ISR (void)
{
  P5OUT ^= BIT1;                            // P5.1 = toggle
  P1IFG &= ~BIT4;                          // P1.4 IFG Cleared
}

So, pls verify your settings for P2IE, P2IES and P2IFG registers!

Rgds
aBUGSworstnightmare 

I am using accelerometer MMA8453 which is connected to the MSP430G2231 via I2C bus. I can initialize and get ack from the MMA8453. But I am not able to read the register from MMA8453. I am using code from SLAA 386A modify just to read the register of MMA8453. Below are my code compile by IAR and assembler included USI_I2CMaster.S43

#include  <msp430G2231.h>

#include "USI_I2CMaster.h"

unsigned char TxData[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
unsigned char RxData[16];
int j,i;
int StatusCallback(unsigned char c); 
void main(void)
{
  WDTCTL = WDTPW+WDTHOLD;                   // disable Watchdog
  if (CALBC1_1MHZ ==0xFF || CALDCO_1MHZ == 0xFF)                                    
  { 
    while(1);                               // If calibration constants erased
                                            // do not load, trap CPU!!
  }  
  BCSCTL1 = CALBC1_1MHZ;                    // Set DCO
  DCOCTL = CALDCO_1MHZ;
  P1DIR |= 0x01;
  P1OUT = 0;
 
  // Initialize USI module, clock ~ SMCLK/128
  TI_USI_I2C_MasterInit(USIDIV_7+USISSEL_3+USICKPL, StatusCallback);
  /* Acknowledge polling function - LED blinks continuously until slave device
  provides an ACK
 TI_USI_I2CSelect(unsigned char SlaveAddress) */
  while(TI_USI_I2CSelect(0x1D))
  {
    P1OUT ^= 0x01;                          // Toggle LED
    for (i = 0; i < 0x3000; i++);           // Delay
  }
 
  P1OUT =0;                                 // Slave acknowledged, LED off
  /*Transmit data to the slave MSP430 device
   TI_USI_I2CWrite(SlaveAddress, Length, Multi, TxData) */
 /* __disable_interrupt();
  TI_USI_I2CWrite(0x1D, 5, 0,TxData);
  __bis_SR_register(LPM0_bits + GIE);*/
 
  /*Read data from the slave MSP430 device
   TI_USI_I2CRead(SlaveAddress, Length, Multi, RxData) */
  __disable_interrupt();
  TI_USI_I2CRead(0x1D, 4, 1,RxData);
  __bis_SR_register(LPM0_bits + GIE);
  
  while(1);                                 // program ends here
}

int StatusCallback(unsigned char c)
{
 return TI_USI_EXIT_LPM;                       // exit active for next transfer
}