address conflict between saadc buffer and fds rec_id

[Lei]

The problem is a little weird and takes me a few hours to address it. But I still don't know how this happens.

Here is the problem, in my application I use saadc to measure voltage. Then I use fds to store some sensor data. I notice that even I set rec_id (e.g. 0x1111) to write sensor data to flash. The rec_id is always changed to saadc value. I suspect the buffer used for saadc is shared with rec_id. But I don't understand why. Is there any way I can change the address for storing rec_id or saadc_buffer?

here is my saadc_callback

/**
 * @brief SAADC (battery) sensor event callback.
 */

void saadc_callback(nrf_drv_saadc_evt_t const * p_saadc_event)
{
    if (p_saadc_event->type == NRF_DRV_SAADC_EVT_DONE)
    {
        ret_code_t err_code;
				char	data_arr_volt[20];

        err_code = nrf_drv_saadc_buffer_convert(p_saadc_event->data.done.p_buffer, SAMPLES_IN_BUFFER);
        APP_ERROR_CHECK(err_code);
 #ifdef UART_PRINTING_ENABLED       
        NRF_LOG_INFO("saadc value= %d\r\n", p_saadc_event->data.done.p_buffer[0]);
				printf("voltage value %d on pin AIN0\r\n",p_saadc_event->data.done.p_buffer[0]);
#endif
				sprintf(data_arr_volt, "%d volt on AIN0_V\r\n", p_saadc_event->data.done.p_buffer[0]);		//get two decimal	
//			ble_nus_data_send(&m_nus, data_array, &length, conn_handle);
			uint16_t length = strlen(data_arr_volt);
			if (m_conn_handle == 0)
			{
				m_conn_handle = m_conn_handle+1;
				err_code = ble_nus_data_send(&m_nus, (uint8_t *)data_arr_volt, &length, m_conn_handle);
			}
			else if(m_conn_handle == 1)
			{
				m_conn_handle = m_conn_handle-1;
				err_code = ble_nus_data_send(&m_nus, (uint8_t *)data_arr_volt, &length, m_conn_handle);
			}			
			
			
}	
    }

}

Here is a regular fds_write()

uint32_t file_id = 0x02000;
uint32_t rec_id_write = 0x1111;
uint32_t rec_id_read = 0x1111;
uint32_t rec_id_delete = 0x1111;


/* Data to write in flash. */
struct 
{
  char string[50] ;                         //Change this size as required.
}fds_data;



fds_record_t record =
{
  .file_id           = 0x02000,
  .key               = 0x1111,
  .data.p_data       = &fds_data,
  /* The length of a record is always expressed in 4-byte units (words). */
  .data.length_words = 50,//(sizeof(fds_data_str) + 3) / 4,                  //Also change this if array size is changed.
};


void fds_write()
{

  ret_code_t rc;

strcpy( fds_data.string, "\n test_fds.\n" );

#ifdef UART_PRINTING_ENABLED
  NRF_LOG_INFO("Writing start");
	printf("Writing start");

	#endif

 fds_record_desc_t desc = {0};
  record.file_id = file_id;


//	fds_data.string = "test"; //{'a', 'b', 'c','d'};
  for(int i=0;i<1;i++)
  {  
    memset(&desc, 0x00, sizeof(fds_record_desc_t)); 
    record.key = rec_id_write;
    rc = fds_record_write(&desc, &record);
    wait_for_write();
    if(rc == FDS_SUCCESS) {
			#ifdef UART_PRINTING_ENABLED
      NRF_LOG_INFO("\nData written with id %d \n",rec_id_write);//
			printf("\nData written with id %d\n",rec_id_write);//
			#endif

    }
    else {
			#ifdef UART_PRINTING_ENABLED
      NRF_LOG_INFO("\nWrite Failed, id %d\n",rec_id_write);
			printf("\nWrite Failed, id %d\n",rec_id_write);
			#endif
    }
    rec_id_write++;
  }  

}

Thanks,

-Lei

[Lei]

Hi Vidar,

Happy holidays!

I didn't do any specific definition for buffer. The saadc is mostly from saadc example. Here are buffer related settings

#define SAMPLES_IN_BUFFER                             1

static nrf_saadc_value_t m_saadc_buffer[SAMPLES_IN_BUFFER];

Here is the saadc_init

/**
 * @brief SAADC (battery) sensor initiate.
 */
void saadc_init(void)
{
    ret_code_t err_code;

		nrf_drv_saadc_config_t saadc_config = NRF_DRV_SAADC_DEFAULT_CONFIG;
		saadc_config.low_power_mode = true;   
    saadc_config.resolution = NRF_SAADC_RESOLUTION_12BIT;
    nrf_saadc_channel_config_t channel_config 
        = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN1);
		channel_config.gain = NRF_SAADC_GAIN1_6;// gain is 1/6 with 0.6V reference. the full range will be 3.6V for 12bit ADC 4096; NRF_SAADC_GAIN1_4;
		channel_config.reference = NRF_SAADC_REFERENCE_INTERNAL;// 0.6V internal is more stable than VDD/4; NRF_SAADC_REFERENCE_VDD4;
    err_code = nrf_drv_saadc_init(&saadc_config, saadc_callback);
    APP_ERROR_CHECK(err_code);
//	NRF_LOG_INFO("error code drv_saadc_init = %d. \r\n", err_code);

    err_code = nrf_drv_saadc_channel_init(0, &channel_config);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_saadc_buffer_convert(m_saadc_buffer, SAMPLES_IN_BUFFER);
    APP_ERROR_CHECK(err_code);
}

If it's due to buffer overrun, how can I avoid it by changing some parameters?

Thanks a lot!

-Lei

[Lei]

Hi Vidar,

I compared my code with saadc example and noticed the difference. In saadc example, in "saadc_init", it used    

static nrf_saadc_value_t m_saadc_buffer[1][SAMPLES_IN_BUFFER];

err_code = nrf_drv_saadc_buffer_convert(m_saadc_buffer[0], SAMPLES_IN_BUFFER);
    APP_ERROR_CHECK(err_code);.

In my case, I just used

static nrf_saadc_value_t m_saadc_buffer[SAMPLES_IN_BUFFER];

err_code = nrf_drv_saadc_buffer_convert(m_saadc_buffer, SAMPLES_IN_BUFFER);
    APP_ERROR_CHECK(err_code);

It seems solving the problem if I change my code the same as saadc example. But I don't understand why. This only happened recently when I added fds into my application. Before that, everything was fine.

Thanks,

-Lei

[Vidar Berg]

Hi Lei,

Sorry for the delayed response. The variable declaration looks to be correct, and I can't really think of any other obvious reasons for the issue you describe. Would you be able to share a minimal version of your project here, or in a private ticekt, so I can try to debug it?

Thanks,

Vidar