LPS22HB address?

[JLee.21]

Hi.

I'm testing pressure using LPS22HB IC.

I connect GND SD0.

But LPS22HB give me address nack.

So I change address "Low" to "High", LPS22HB give me strange pressure value and not address nack.

Why do LPS22HB address strange?

Thank you.

[Tesla DeLorean]

Address would be 0xB8 on architectures like the STM32 where the I2C address is considered the high order 7-bits

0xB8 = (0x5C << 1)

[JLee.21]

Thank you answer.

I know your answer.

My MCU transmit 0xB8, but LPS22HB dosen't ack.

So transmit 0xBA, LPS22HB transmits ack and pressure value.

But pressure value is strange value.

[Eleon BORLINI]

Hi @JLee.21​ , which I2C pull-up resistors are you mounting on your board? Regards

[JLee.21]

Hi, Eleon BoRLINI.

Yes. I mount I2C Pull-up(4.7k) resistors my boards.

It is near another IC with using I2C.

Also i have a question.

I'm using NRF52832.

I set

do{

    err_code = nrf_drv_twi_init(m_drv_pressure.cfg.p_twi_instance, m_drv_pressure.cfg.p_twi_cfg, twi_handler, NULL);

//    APP_ERROR_CHECK(err_code);

    if(NRF_SUCCESS != err_code)

    {

      break;

    }

    nrf_drv_twi_enable(m_drv_pressure.cfg.p_twi_instance);

  }while(0);

  nrf_delay_ms(5);//wait for loading trimming parameters

  lps22hb_reset_set(&dev_ctx, PROPERTY_ENABLE);

  do {

   lps22hb_reset_get(&dev_ctx, &rst);

  } while (rst);   

  lps22hb_SD0_SA0_set(&dev_ctx, sd0_sa0_data);

//  lps22hb_auto_add_inc_set(&dev_ctx, PROPERTY_ENABLE);

//  lps22hb_CTE_BIT_set(&dev_ctx, cte_data);

  lps22hb_block_data_update_set(&dev_ctx, PROPERTY_ENABLE);

  lps22hb_data_rate_set(&dev_ctx, LPS22HB_POWER_DOWN);

  lps22hb_one_shoot_trigger_set(&dev_ctx, PROPERTY_ENABLE);

  nrf_delay_ms(2);

//  lps22hb_low_pass_filter_mode_set(&dev_ctx, LPS22HB_LPF_ODR_DIV_2);

//  lps22hb_data_rate_set(&dev_ctx, LPS22HB_ODR_10_Hz);

  lps22hb_temp_data_ready_get(&dev_ctx, &reg1);

  do

  {     

    timeout--;

    if(timeout <= 0) 

    {

      NRF_LOG_DEBUG("temp timeout\r\n");

      return 0;

    }

  }while(!reg1);

  if (reg1)

  {

   memset(data_raw_temperature.u8bit, 0x00, sizeof(int16_t));

   lps22hb_temperature_raw_get(&dev_ctx, data_raw_temperature.u8bit);

//   temp = lps22hb_from_lsb_to_degc(data_raw_temperature.i16bit);

//   NRF_LOG_DEBUG("temp : "NRF_LOG_FLOAT_MARKER" ",   NRF_LOG_FLOAT(temp));

  }

  timeout = I2C_TIMEOUT;

  lps22hb_press_data_ready_get(&dev_ctx, &reg);

  do

  {     

    timeout--;

    if(timeout <= 0) 

    {

      NRF_LOG_DEBUG("pressure timeout, pressure status : %d, temp status : %d\r\n", reg, reg1);

      *pressure = old_pressure;

      return 0;

    }

  }while(!reg);

  if (reg)

  {

   memset(data_raw_pressure.u8bit, 0x00, sizeof(int32_t));

   lps22hb_pressure_raw_get(&dev_ctx, data_raw_pressure.u8bit);

*pressure = data_raw_pressure.i32bit;

    old_pressure = data_raw_pressure.i32bit;

  }

  nrf_drv_twi_disable(m_drv_pressure.cfg.p_twi_instance);

  nrf_drv_twi_uninit(m_drv_pressure.cfg.p_twi_instance);

But LPS22HB first pressure and temperature value are 0x00 after booting.

ctrl_reg(27h) has p_da(0x00) and t_da(0x01).

Next LPS22HB pressure and temperature value are ok.

Sometimes LPS22HB first pressure value 0x800 after booting.

Next LPS22HB pressure value 0x66.

How should i do?

Thank you.

[Eleon BORLINI]

Hi @JLee.21​ , it's a dummy suggestion, but I would suggest you to discard the 1st data, if you can do it. Pressure and temperature doesn't require a high ODR (output data rate) as in the case of a motion sensor or a microphone, so you could manage this issue in this way. Regards

[JLee.21]

Hi, Eleon BoRLINI.

Thank you answer.

But always LPS22HB has pressure value 0x66 after LPS22HB first pressure value 0x800.

It is removed after main power off.

I know it has complex problem, but What happened?

I have a question.

Under does code correct?

I searched I2C Bus in DT0132 Design Tip.pdf

int32_t lps22hb_SD0_SA0_set(stmdev_ctx_t *ctx, uint8_t val)

{

 uint32_t ctrl_reg;

 int32_t ret;

 ret = lps22hb_read_reg(ctx, 0x49, (uint8_t*)&ctrl_reg, 1);

 if(ret == 0){

  ctrl_reg |= (uint8_t)val;

  ret = lps22hb_write_reg(ctx, 0x49, (uint8_t*)&ctrl_reg, 1);

 }

 return ret;

}

Thank you.