How do I switch between "Stream-to-FIFO" and "Stream" mode for LSM6DS3TR-C?

[ASoni.2]

Hi, I need advise regarding my application. I can store historic data using Stream-to-FIFO mode based on single tap interrupt in buffer A. But, I cannot get data after the tap interrupt in buffer B when switching FIFO mode to Streaming mode. I believe I am not configuring the sensor properly to switch from one mode to another. My code is listed below. It collects and store historical data in buffer A and calculates threshold. If threshold is higher, then micro-controller is instructed to switch to the streaming mode and to store data in buffer B. This code returns watermark value 0 for the second part of the code (for buffer B part). It should be 1 for FIFO to output data.

S32 get_lsm6ds3_fifo_acceleration_angular_rate_data_s16(S16 *acceleration_mg, S16 *angular_rate_mdps)
{
  uint16_t numA = 0;
  uint16_t numB = 0;
  uint16_t num_patternA = 0;
  uint16_t num_patternB = 0;
  uint8_t watermA = 0;
  uint8_t watermB = 0;
  S32 error;
  volatile uint16_t acc_magn = 0;
 
  error = lsm6ds3tr_c_fifo_wtm_flag_get(&lsm6ds3, &watermA);
  kal_prompt_trace(MOD_ABM,"001 error:%d, waterm:%d", error,watermA);
  if(error!=STATUS_OK) return STATUS_FAIL;
    if(watermA)
      {
	error = lsm6ds3tr_c_fifo_data_level_get(&lsm6ds3, &numA);
	kal_prompt_trace(MOD_ABM,"002 error:%d, num:%d", error,numA); 
	if(error!=STATUS_OK) return error;
		
	num_patternA = numA/pattern_len;
	kal_prompt_trace(MOD_ABM,"003 num_pattern:%d, pattern_len:%d", num_patternA,pattern_len); 
	while (num_patternA-- > 0){
		lsm6ds3tr_c_fifo_raw_data_get(&lsm6ds3, data_raw_angular_rate.u8bit, 3*sizeof(int16_t));
 
		*angular_rate_mdps = lsm6ds3tr_c_from_fs250dps_to_mdps(data_raw_angular_rate.i16bit[0]);
		*(angular_rate_mdps+1) = lsm6ds3tr_c_from_fs250dps_to_mdps(data_raw_angular_rate.i16bit[1]);
		*(angular_rate_mdps+2) = lsm6ds3tr_c_from_fs250dps_to_mdps(data_raw_angular_rate.i16bit[2]);
				
		lsm6ds3tr_c_fifo_raw_data_get(&lsm6ds3, data_raw_acceleration.u8bit, 3*sizeof(int16_t));
 
		*acceleration_mg = lsm6ds3tr_c_from_fs2g_to_mg(data_raw_acceleration.i16bit[0]);
		*(acceleration_mg+1) = lsm6ds3tr_c_from_fs2g_to_mg(data_raw_acceleration.i16bit[1]);
		*(acceleration_mg+2) = lsm6ds3tr_c_from_fs2g_to_mg(data_raw_acceleration.i16bit[2]);
 
		acc_x_buffer_a[num_patternA]= acceleration_mg[0];
		acc_y_buffer_a[num_patternA]= acceleration_mg[1];
		acc_z_buffer_a[num_patternA]= acceleration_mg[2];
		gyro_x_buffer_a[num_patternA] = angular_rate_mdps[0];
		gyro_y_buffer_a[num_patternA] = angular_rate_mdps[1];
		gyro_z_buffer_a[num_patternA] = angular_rate_mdps[2];
 
		acc_magn = sqrt(pow(acc_x_buffer_a[num_patternA], 2)+ pow(acc_y_buffer_a[num_patternA], 2) + pow(acc_z_buffer_a[num_patternA], 2));
				
		kal_prompt_trace(MOD_ABM,"BufA_No: %d, ACC: %d, %d, %d, GYR: %d, %d, %d, MAG: %d", num_patternA, acc_x_buffer_a[num_patternA], acc_y_buffer_a[num_patternA], acc_z_buffer_a[num_patternA], gyro_x_buffer_a[num_patternA], gyro_y_buffer_a[num_patternA], gyro_z_buffer_a[num_patternA], acc_magn);
		}		
		lsm6ds3tr_c_fifo_mode_set(&lsm6ds3, LSM6DS3TR_C_BYPASS_MODE);
		lsm6ds3tr_c_fifo_mode_set(&lsm6ds3, LSM6DS3TR_C_STREAM_TO_FIFO_MODE);
		
		if( acc_magn > 0)
		{
		lsm6ds3tr_c_fifo_mode_set(&lsm6ds3, LSM6DS3TR_C_BYPASS_MODE);
		lsm6ds3tr_c_fifo_mode_set(&lsm6ds3, LSM6DS3TR_C_STREAM_MODE);
						
		lsm6ds3tr_c_pin_int1_route_get(&lsm6ds3, &int_1_reg);
		int_1_reg.int1_fth = PROPERTY_ENABLE;
		lsm6ds3tr_c_pin_int1_route_set(&lsm6ds3, int_1_reg);
 
		error = lsm6ds3tr_c_fifo_wtm_flag_get(&lsm6ds3, &watermB);
		kal_prompt_trace(MOD_ABM,"100 error:%d, watermB:%d", error,watermB);
		if(error!=STATUS_OK) return STATUS_FAIL;
		if(watermB)
		{
			error = lsm6ds3tr_c_fifo_data_level_get(&lsm6ds3, &numB);
			kal_prompt_trace(MOD_ABM,"200 error:%d, num:%d", error,numB); 
			if(error!=STATUS_OK) return error;
		
			num_patternB = numB/pattern_len;
			kal_prompt_trace(MOD_ABM,"300 num_pattern:%d, pattern_len:%d", num_patternB,pattern_len); 
			while (num_patternB-- > 0)
			{
			lsm6ds3tr_c_fifo_raw_data_get(&lsm6ds3, data_raw_angular_rate.u8bit, 3*sizeof(int16_t));
 
			*angular_rate_mdps = lsm6ds3tr_c_from_fs250dps_to_mdps(data_raw_angular_rate.i16bit[0]);
			*(angular_rate_mdps+1) = lsm6ds3tr_c_from_fs250dps_to_mdps(data_raw_angular_rate.i16bit[1]);
			*(angular_rate_mdps+2) = lsm6ds3tr_c_from_fs250dps_to_mdps(data_raw_angular_rate.i16bit[2]);
				
			lsm6ds3tr_c_fifo_raw_data_get(&lsm6ds3, data_raw_acceleration.u8bit, 3*sizeof(int16_t));
 
			*acceleration_mg = lsm6ds3tr_c_from_fs2g_to_mg(data_raw_acceleration.i16bit[0]);
			*(acceleration_mg+1) = lsm6ds3tr_c_from_fs2g_to_mg(data_raw_acceleration.i16bit[1]);
			*(acceleration_mg+2) = lsm6ds3tr_c_from_fs2g_to_mg(data_raw_acceleration.i16bit[2]);
 
			acc_x_buffer_b[num_patternB]= acceleration_mg[0];
			acc_y_buffer_b[num_patternB]= acceleration_mg[1];
			acc_z_buffer_b[num_patternB]= acceleration_mg[2];
			gyro_x_buffer_b[num_patternB] = angular_rate_mdps[0];
			gyro_y_buffer_b[num_patternB] = angular_rate_mdps[1];
			gyro_z_buffer_b[num_patternB] = angular_rate_mdps[2];
				
			kal_prompt_trace(MOD_ABM,"BufB_No: %d, ACC: %d, %d, %d, GYRO: %d, %d, %d", num_patternB, acc_x_buffer_b[num_patternB], acc_y_buffer_b[num_patternB], acc_z_buffer_b[num_patternB], gyro_x_buffer_b[num_patternB], gyro_y_buffer_b[num_patternB], gyro_z_buffer_b[num_patternB]);
 
			}
		}
	}
	return STATUS_OK;
  }
  return STATUS_FAIL;
}

[Eleon BORLINI · Accepted solution]

Hi @ASoni.2​ , back to this topic after long time... Your question is that, when you switch from"Stream-to-FIFO" to "Stream" mode, you cannot get no more data after the tap interrupt, right? Let's consider the device working conditions listed here below (AN5130 p.78):

I believe you should esc the "Continuous to FIFO" mode, enter the Bypass mode (000b) and then switching to the Bypass-to-continuous mode (100b), which should be triggered by the interrupt and starting with the filling of buffer B.

Regards

[ASoni.2]

Hi @Eleon BORLINI​  Yes, I am fine with this query now. I have configured the sensor as stated in your answer.