MAC Address BLE scan filter not working

RE: MAC Address BLE scan filter not working

Thabet — Wed, 15 Dec 2021 15:54:51 GMT

Vidar Berg My filters are started normally and successfully, I just can't get a match with the address, through your example code it worked, but with my code it doesn't work, and in the filters part both codes are identical!

I already have a ticket but I don't get any answers...please help me!

I can successfully filter and get connection with all other filters but the address filter, I will open another ticket, mention you, and I will privately send my code to you. thanks.

RE: MAC Address BLE scan filter not working

Daniela_A — Wed, 15 Dec 2021 15:32:25 GMT

Hello,

I started from scratch. I re-downloaded the SDK, opened your files and proogram my device and now IT WORKS!!! The problem was definetely related to the SDK.

Thank you so very much for you time, help and all possible the solutions that you suggested 😃

I am really grateful

RE: MAC Address BLE scan filter not working

Vidar Berg — Wed, 15 Dec 2021 14:44:10 GMT

Hello,

I'm finally able to replicate the problem now with your .hex file.

I get this instead of an address match:

Now, the question is what's different between our builds. Did you download a new copy of the SDK earlier?

Here is the hex file I built:

devzone.nordicsemi.com/.../3731.ble_5F00_app_5F00_blinky_5F00_c_5F00_pca10056_5F00_s140.hex

You can program it with nrfjprog --program ble_app_blinky_c_pca10056_s140.hex --sectorerase -r

Thabet, it's probably better if you create a new ticket for this. I doubt it's related to the issues discussed here. 1 step is to make sure the filter set function returns NRF_SUCCESS and not an error code.

RE: MAC Address BLE scan filter not working

Daniela_A — Wed, 15 Dec 2021 14:29:15 GMT

Hello,

Sure thing. Here it is:

devzone.nordicsemi.com/.../7888.ble_5F00_app_5F00_blinky_5F00_c_5F00_pca10056_5F00_s140.hex

Thanks

RE: MAC Address BLE scan filter not working

Thabet — Wed, 15 Dec 2021 14:12:43 GMT

I have the same problem as this topic, I can use all filters except the address filter, I use SDK 17.0.2.

With the example provided by vidar and making the modification for the MAC I want to filter it worked, but with my code in SDK 17.0.2 with the filter definitions identical to the example provided by Vidar, the filter doesn't work!

RE: MAC Address BLE scan filter not working

Vidar Berg — Wed, 15 Dec 2021 14:04:47 GMT

Hello,

Could you upload the hex file as well so I can try to test it here? It gets placed in the build directory here \pca10056\s140\ses\Output\<Release\Debug>\Exe\

RE: MAC Address BLE scan filter not working

Daniela_A — Wed, 15 Dec 2021 13:50:47 GMT

Hello,

I have run the code in the newest SDK version and it won´t work. I am even printing the address the filter is set to and it is correct; however, the same address and type appears in the not found list,

Thanks

RE: MAC Address BLE scan filter not working

Vidar Berg — Tue, 14 Dec 2021 17:30:22 GMT

Hello,

This doesn't quite add up. A private address is typically updated every 15 minutes to a completely different one, so you should have noticed by now if the address was not static. The address was registered as a public address as well, further indicating that it's not really a private address.

The advertiser should set the TxAdd bit in the advertisement packet to indicate that it is using a public address type, and it's not doing that since the Softdevice thinks it's private address (it's not possible to tell if it's a public address by looking at the MSBs like with the other address types)

That said, the scanner module appears to only care about the address and simply ignore the type, so it's still not clear to me why you are not getting a filter match.

Edit: The address type is actually set to public. They type is printed before the address, not after. I suggest you try to build my sample with a fresh copy of SDK 17.1.0 in case there is a chance the scanner module may have been modified in your current copy.

RE: MAC Address BLE scan filter not working

Daniela_A — Tue, 14 Dec 2021 16:31:03 GMT

Hello,

Yes, the address is shown. And the type is 0x2 that. as you said in the first place, is "private resolvable".
So I guess I will need to find another strategy to filter the advertisement packets.

Thank you

RE: MAC Address BLE scan filter not working

Vidar Berg — Tue, 14 Dec 2021 15:24:17 GMT

Hello,

OK, can you log the addresses of the advertisment packets that are received when you get NRF_BLE_SCAN_EVT_NOT_FOUND and see if your device shows up or not?

/**@brief Function for handling Scaning events.
 *
 * @param[in]   p_scan_evt   Scanning event.
 */
static void scan_evt_handler(scan_evt_t const * p_scan_evt)
{
    ret_code_t err_code;

    ble_gap_addr_t const * peer_addr = &p_scan_evt->params.p_not_found->peer_addr;

    switch(p_scan_evt->scan_evt_id)
    {
        case NRF_BLE_SCAN_EVT_CONNECTING_ERROR:
            err_code = p_scan_evt->params.connecting_err.err_code;
            APP_ERROR_CHECK(err_code);
            break;
        case NRF_BLE_SCAN_EVT_FILTER_MATCH:
            NRF_LOG_INFO("Filter match")
            break;
        case NRF_BLE_SCAN_EVT_NOT_FOUND:
             NRF_LOG_INFO("Address type: 0x%x, \nAddress: ", peer_addr->addr_type); 
             NRF_LOG_HEXDUMP_INFO(peer_addr->addr, sizeof(peer_addr->addr));
            
            break;
        default:
          break;
    }
}

RE: MAC Address BLE scan filter not working

Daniela_A — Tue, 14 Dec 2021 15:07:34 GMT

Hello,

Yes, I am getting the NRF_BLE_SCAN_EVT_NOT_FOUND event, exactly.

RE: MAC Address BLE scan filter not working

Vidar Berg — Tue, 14 Dec 2021 14:48:18 GMT

Hello,

That's strange, I even tested it here with a peripheral advertising the same public address (AC:23:3F:A9:EF:E2).

Do you get other events such as NRF_BLE_SCAN_EVT_NOT_FOUND in your scanner callback?

RE: MAC Address BLE scan filter not working

Daniela_A — Tue, 14 Dec 2021 14:37:32 GMT

Hello,

I have tested the code that you shared with me. Unfortunately, no events are being triggered. I´m attaching a screenshot of the debug window. It remains there waiting for an event to be triggered.

Thanks

RE: MAC Address BLE scan filter not working

Vidar Berg — Tue, 14 Dec 2021 13:24:29 GMT

Sorry, I must have forgotten to include the attachment. It's added to my previous response now.

RE: MAC Address BLE scan filter not working

Daniela_A — Tue, 14 Dec 2021 13:19:47 GMT

Hello and thank you for you support!

Where can I see the project that you attached?

RE: MAC Address BLE scan filter not working

Vidar Berg — Tue, 14 Dec 2021 08:38:46 GMT

Hello,

Please try my project attached below and see if it's able to connect with your device (has log output on UART and RTT which says when its connected/there is a filter match). It's the ble_app_blinky_c example which I have modified to include your address filter.

Edit: including missing attachment:

devzone.nordicsemi.com/.../nRF5_5F00_SDK_5F00_17.1.0_5F00_ble_5F00_app_5F00_connect_5F00_to_5F00_AC233FA9EFE2.zip

RE: MAC Address BLE scan filter not working

Daniela_A — Mon, 13 Dec 2021 15:00:23 GMT

Hello,

I have changed the address type to public. However, the MAC address filter is still not working. I tried using another MAC address (from another device) and it is not workling either.

RE: MAC Address BLE scan filter not working

Vidar Berg — Fri, 10 Dec 2021 15:20:35 GMT

Hello,

Have you changed the address type to public, and are you monitoring for the NRF_BLE_SCAN_EVT_FILTER_MATCH scan_evt_handler. I'm not seeing any other issues in the code you posted.

RE: MAC Address BLE scan filter not working

Daniela_A — Fri, 10 Dec 2021 13:36:48 GMT

Hello,

Then, could you please take a look to the code of the very first post of this forum?
Because, apparently, the filter is not working properly

Thanks

RE: MAC Address BLE scan filter not working

Vidar Berg — Fri, 10 Dec 2021 13:23:10 GMT

Hello,

Yes, a public address will not change like a private address would.

RE: MAC Address BLE scan filter not working

Daniela_A — Fri, 10 Dec 2021 13:21:37 GMT

Hello,

Taking into account that the address is public, would it possible for me to use to MAC Address filter to find the device?

Thanks

RE: MAC Address BLE scan filter not working

Vidar Berg — Fri, 10 Dec 2021 08:03:15 GMT

Hello,

They are actually using a public address type. I looked it up here: https://hwaddress.com/oui-iab/AC-23-3F/. Unlike the other address types, it's not possible to tell if an address is public just by looking at the MSB bits , which means you have to get the address type from the adv. report event.

I'm not sure why they have duplicated the address in the Manufacturer data field.

RE: MAC Address BLE scan filter not working

Daniela_A — Thu, 09 Dec 2021 20:29:41 GMT

Hello Vidar,

I am a bit confused right now, because you said that "The actual mac address is not included in the advertisment when a private address is used"; however, this is what I see when I scan the device with nRFConnect mobile app

As you can see, the MAC address is present in the advertisement packet. What is happening, then?

RE: MAC Address BLE scan filter not working

Vidar Berg — Thu, 09 Dec 2021 14:21:19 GMT

Hello,

No problem 🙂The address type is included in the adv. report event (adv_report->peer_addr.addr_type). The actual mac address is not included in the advertisment when a private address is used. It's typically only exchanged during bonding.

Best regards,

Vidar

RE: MAC Address BLE scan filter not working

Daniela_A — Wed, 08 Dec 2021 21:21:15 GMT

Hello Vidar and thank you for your answers.

Now I have some more quesions:

How do you know that the device might be using a private resolvable address? (I´m curious and I will like to earn to identify tem as well)
Is this address the same as the MAC address of the device?

Thank you

PS: Thanks on your comments about the ADV_REPORT event