I couldnt find mobile phone using NRF52833 just finding BLE peripherals (Software: ble_app_uart_c)

[Huseyin T.]

Hi everyone,

i am developing a bluetooth scanner device using nrf52833 and using the "ble_app_uart_c and softdevice:122" example as software. I am reading scanning data in "scan_evt_handler" from "p_scan_evt->params.p_whitelist_adv_report ->data.p_data". While reviewing scanning result on mobaxterm i noticed my board can find only ble peripherals(such as smart watch, ear buds, mouse) not mobile phone or pc. I have nrf52840 dongle and i scaned the bluetooth device via nrf52840 dongle using "nrf connect app" on my pc, i got same result(couldnt find mobile phone). Then i have downloaded "nrf_connect" app on my mobile phone and when i run the "nrf connect" app in advertiser mode, nrf52833 can find the my mobile phone. How can i find/discover the mobile phone without using any mobile app. The relevant datas added below.


raw Data = 1eff060001092002da7e8d4e36d854dbd96024079a4e4f8dc28a1570209ea9
Length = 1e
Man Spec Data = ff
Company ID = 0600    //(0006 Microsoft)
01092002da7e8d4e36d854dbd96024079a4e4f8dc28a1570209ea9


Raw Data = 1eff4c00071901242021998f1100042915418df26359029e5fcb18378c9748
Length = 1e
Man Spec Data = ff
Company ID = 4c00(004c Apple)
071901242021998f1100042915418df26359029e5fcb18378c9748

Raw Data = 13095265646d6920576174636820332033464431
Length = 13
AD = Complate Local Name 09
Redmi Watch 3 3FD1(5265646d6920576174636820332033464431)

[Karl Ylvisaker]

Hello,

While reviewing scanning result on mobaxterm i noticed my board can find only ble peripherals(such as smart watch, ear buds, mouse) not mobile phone or pc.

A scanner will only ever be able to find peripherals, since it listens for the advertising packets from the peripherals.
Are you certain that your pc and mobile phones in these cases were configured to be peripheral devices? If they were not, they typically default to being central devices, which means that when you enter their 'pair new devices' state they will be scanning for advertising packets to connect to.
A scanner can never be found by another device since it only listens for other radio activity - it never sends anything itself.

Best regards,
Karl

[Huseyin T.]

Hello Karl,

so how can my computer find my mobile phone on normal mode?

[Karl Ylvisaker]

Hello,

Could it be that your phone is advertising as a Bluetooth Classic device? If so, it will not show up in the nRF Connect for Desktop application.
Are you familiar with the nRF Sniffer tool? It would be great to see a sniffer trace of the advertising from the phone to see exactly what is being sent.

Best regards,
Karl

[Huseyin T.]

Hi again,

i have used to nrf sniffer tool with wireshark and listing bluetooth messages but nrf52840 dongle receive too many messages (1000+) in second. I found my mobile phone access address and then i have tried filtering to received messagges using "btle.access_address == 0x8e89bed6 && btcommon.eir_ad.entry.company_id == 0x0075", however i couldnt understand is this device a phone or peripheral. I think my mobile phone advertising only "ADV_NONCONN_IND" mode. How can i find my phone using this messagges. (Device Name, is phone).

[Huseyin T.]

Hi,

if i use ble active mode on nrf52833 , can i find my phone.

[Karl Ylvisaker]

Hello,

Huseyin T. said:

I found my mobile phone access address and then i have tried filtering to received messagges using "btle.access_address == 0x8e89bed6 && btcommon.eir_ad.entry.company_id == 0x0075", however i couldnt understand is this device a phone or peripheral. I think my mobile phone advertising only "ADV_NONCONN_IND" mode. How can i find my phone using this messagges. (Device Name, is phone).

If you know your phone's address you should use the 'Device: All advertising devices' dropdown menu to select it directly, so that the sniffer will only look for activity related to this specific device. This will also make the sniffer follow into any connections entered by said device.

Huseyin T. said:

if i use ble active mode on nrf52833 , can i find my phone.

I am not sure if I understand what you mean by this, are you asking whether you can find the phone by using active scanning on the nRF52833? You will need to perform scanning to find the phone if the phone is advertising as a peripheral, the difference between active and passive scanning is whether or not the scanner also sends a scan request to the advertising devices, to ask for more data.

Best regards,
Karl

[Huseyin T.]

Hi Karl Again,

Thank you for your reply. I have new question. I am sniffering ble device using nrf52833 and printing the sniffed device datas to mobaxterm. I notice that i have 2 parameters "peer_addr.addr_type" and "role" as shown figure below. What is the What i want to ask what is the difference of addr_type and roles. My guess is peer_addr.addr_type pdu_type because as far as i can see it take values beetwen 0 and 5. So what does the "roles" variable mean? i couldnt find anything.

PDU Types:

ADV_IND

ADV_DIRECT_IND

ADV_NONCONN_IND

ADV_SCAN_IND

[Karl Ylvisaker]

Hello,

Huseyin T. said:

Thank you for your reply.

No problem at all, I am happy to help!

Huseyin T. said:

I am sniffering ble device using nrf52833 and printing the sniffed device datas to mobaxterm. I notice that i have 2 parameters "peer_addr.addr_type" and "role" as shown figure below. What is the What i want to ask what is the difference of addr_type and roles. My guess is peer_addr.addr_type pdu_type because as far as i can see it take values beetwen 0 and 5. So what does the "roles" variable mean? i couldnt find anything.

I am not sure that I understand what you are asking about here - the screenshot you shared seems to be a memory readout of a NRF_BLE_SCAN_EVT_NOT_FOUND, in which case the values of the connected parameters are invalid/not used for anything, but you specifically ask about sniffer activities.
Could you share the sniffer trace you are looking at, and reference directly to packet numbers that you would like to discuss or have questions about instead?

Best regards,
Karl

[Huseyin T.]

Hi,

İ am sniffing ble messages and all events i get are NRF_BLE_SCAN_EVT_NOT_FOUND, but i can read device name or manufacturer datas from "p_scan_evt->params.p_whitelist_adv_report ->data.p_data". i guess role and other parameters are corrrect.

[Karl Ylvisaker]

Hello,

Please share the trace using the Insert -> File option and reference specific packet numbers in the trace if you would like for me to take a closer look.

Best regards,
Karl