Long range data transfer from central to peripheral

[sowmiya]

Hi,

 In my application i am trying out to transfer data in Long range BLE_GAP_PHY_CODED mode , i have set my peripheral has to advertise in PHY coded mode below is the advertising init function which changed to phy coded. i am using ble_app_blinky_c  for central and ble_app_blinky  example in peripheral

static void advertising_init_phycoded(uint16_t adv_timeout)
{
ret_code_t err_code;
ble_advdata_t advdata;
ble_advdata_t srdata;
ble_advdata_manuf_data_t manuf_specific_data;

manuf_specific_data.company_identifier = APP_COMPANY_IDENTIFIER;
manuf_specific_data.data.p_data = (uint8_t *) NORMAL_BEACON;
manuf_specific_data.data.size = APP_BEACON_INFO_LENGTH;

// ble_uuid_t adv_uuids[] = {{LBS_UUID_SERVICE, m_lbs.uuid_type}};

// Build and set advertising data.
memset(&advdata, 0, sizeof(advdata));

// advdata.name_type = BLE_ADVDATA_NO_NAME;
advdata.include_appearance = false;
advdata.flags = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
advdata.p_manuf_specific_data = &manuf_specific_data;
memset(&srdata, 0, sizeof(srdata));
// srdata.uuids_complete.uuid_cnt = sizeof(adv_uuids) / sizeof(adv_uuids[0]);
// srdata.uuids_complete.p_uuids = adv_uuids;

err_code = ble_advdata_encode(&advdata, m_adv_data.adv_data.p_data, &m_adv_data.adv_data.len);
APP_ERROR_CHECK(err_code);

err_code = ble_advdata_encode(&srdata, m_adv_data.scan_rsp_data.p_data, &m_adv_data.scan_rsp_data.len);
APP_ERROR_CHECK(err_code);

ble_gap_adv_params_t adv_params;

// Set advertising parameters.
memset(&adv_params, 0, sizeof(adv_params));

adv_params.primary_phy = BLE_GAP_PHY_CODED;
adv_params.secondary_phy = BLE_GAP_PHY_CODED;
adv_params.properties.type = BLE_GAP_ADV_TYPE_EXTENDED_CONNECTABLE_NONSCANNABLE_UNDIRECTED;
// }
// else{
// adv_params.properties.type = BLE_GAP_ADV_TYPE_NONCONNECTABLE_SCANNABLE_UNDIRECTED;
// }
adv_params.p_peer_addr = NULL;
adv_params.filter_policy = BLE_GAP_ADV_FP_ANY;
adv_params.scan_req_notification = 1;
if(battery_level == 0 || battery_level >= BATTERY_VOLTAGE_MIN_FOR_DISPLAY){
adv_params.interval = COASTER_ADV_INTERVAL;
}
else{
adv_params.interval = LOW_LEVEL_BATTERY_INTERVAL;
}
adv_params.duration = adv_timeout; // Never time out.

err_code = sd_ble_gap_adv_set_configure(&m_adv_handle, &m_adv_data, &adv_params);
APP_ERROR_CHECK(err_code);
sd_ble_gap_adv_set_configure(&m_adv_handle,&m_adv_data,&adv_params);
NRF_LOG_INFO("m_adv_data.adv_data.p_data address %p", m_adv_data.adv_data.p_data);
}

same as my central is in scannng the beacon which is in phy coded and gets connected also but no data transfrer happens after MTU request gets disconnecting from the peripheral .

#define SCAN_INTERVAL (2*0x00A0) /**< Determines scan interval in units of 0.625 millisecond. */
#define SCAN_WINDOW 0x00A0 /**< Determines scan window in units of 0.625 millisecond. */
#define SCAN_DURATION 0x0000

static ble_gap_scan_params_t m_scan_param = /**< Scan parameters requested for scanning and connection. */
{
.active = 0x01,
.interval = SCAN_INTERVAL,
.window = SCAN_WINDOW,
.filter_policy = BLE_GAP_SCAN_FP_ACCEPT_ALL,
.timeout = SCAN_DURATION,
.scan_phys = BLE_GAP_PHY_1MBPS|BLE_GAP_PHY_CODED,
.extended = 1,
};

please advise what i have missed here for PHY coded data transfer .

Thanks in advance.

best regards.

[sowmiya]

Hi ovrebekk ,

ovrebekk said:

Another reason to use the ble_app_uart example is that it handles the MTU exchange for you. The blinky example does not, since you don't need extended MTU to send a single byte back and forth ;)

blinky i have changed the MTU to transfer 247 bytes data  and increased the MTU size you can see in LBS service in my demo example and the reason almost its all done In 1mpbs mode data transfer already in my project and now adding PHYcoded data transfer.

i have tested with ble_app_uart_example and the same way i have tried out still its sending only 27 bytes in PHY coded .

       

[ovrebekk]

Hi Sowmiya

Are you saying that almost exactly the same code (only changed to support coded phy) will allow you to send 247 bytes of data in 1M mode, but not in coded phy mode?

Can you run the two examples with logging enabled to see if there are any warning or error messages printed that might indicate why the MTU size can not be increased?

Could you try to capture a sniffer trace of the BLE communication when you connect the devices and try to send 247 bytes of data (using the nRF Sniffer for instance)?

Best regards
Torbjørn

[sowmiya]

hi ovrebekk,

     Its working in LR mode data transfer .NRF_SDH_BLE_GAP_EVENT_LENGTH increased the event lenght too , Its working now 

Thanks.

[ovrebekk]

Hi

That is great to hear. I will consider the case resolved then

Best regards
Torbjørn