BEACON SCANNER to read more than 31 byte of advertising data

RE: BEACON SCANNER to read more than 31 byte of advertising data

VIGNESH C — Mon, 20 Jan 2020 04:28:36 GMT

Hi Vidar Berg,

Now i'm able to receive entire advertising data. Has received the remaining advertising data in separate event.

Thanks for the help.

RE: BEACON SCANNER to read more than 31 byte of advertising data

Vidar Berg — Fri, 17 Jan 2020 10:28:36 GMT

[quote user="vignesh"]But how can i receive the remaining advertising data (i.e after 31st byte)[/quote]

It comes in two separate events. Max. payload for each event is 31 bytes.

[quote user="vignesh"]How to parse scan response packet? can you please help on this..[/quote]

You can probably to in the same way as you did for the main advertisement packet. Can you post some code snippets so I can see how you have implemented this?

RE: BEACON SCANNER to read more than 31 byte of advertising data

VIGNESH C — Fri, 17 Jan 2020 04:52:00 GMT

Hi Vidar Berg,

Have tested the scan response bit in scanner callback, it is hitting the break-point.

But how can i receive the remaining advertising data (i.e after 31st byte)

Even in scanner callback i can see only 31 byte of advertising data, also the packet length is 32 bytes

How to parse scan response packet? can you please help on this..

RE: BEACON SCANNER to read more than 31 byte of advertising data

Vidar Berg — Tue, 14 Jan 2020 16:48:22 GMT

Hi,

The scan response comes in a separate event, first, you get the data of the main adv. packet (max. 31 bytes), then you get the scan response. Please verify that you do you get scan response packets. One way you can to that is to check the scan response bit in your scanner callback as shown below.

static void scan_evt_handler(scan_evt_t const * p_scan_evt)
{
    ret_code_t err_code;

    ble_gap_evt_adv_report_t const * adv_report;

    switch(p_scan_evt->scan_evt_id)
    {
         case NRF_BLE_SCAN_EVT_NOT_FOUND:
            adv_report = p_scan_evt->params.filter_match.p_adv_report;

            if (adv_report->type.scan_response)
            {
                __BKPT(0); //TODO: parse scan response packet
            }
            break;

         default:
             break;
    }
}

RE: BEACON SCANNER to read more than 31 byte of advertising data

VIGNESH C — Tue, 14 Jan 2020 04:32:05 GMT

Hi Vidar Berg, anything on this?

RE: BEACON SCANNER to read more than 31 byte of advertising data

VIGNESH C — Mon, 13 Jan 2020 13:54:06 GMT

Hi Vidar Berg,

I haven't put any break-points.

Actually i am printing first 50 byes of received data in J-link RTT viewer.

30 bytes i'm able to receive proper data, but after from 31 to 50th bytes, i'm receiving all zeros, which should be Accelerator data.

I have used "nRF connect" mobile app, in that i can be able to see the valid data from 31 to 50th bytes.

Is there any changes i need to make in "sdk_config.h" file like

#define NRF_BLE_SCAN_BUFFER 31

#define NRF_BLE_SCAN_NAME_MAX_LEN 31

#define NRF_BLE_SCAN_SHORT_NAME_MAX_LEN 31

etc..

I have changed this bytes to 50 but didn't received more than 30 bytes.

RE: BEACON SCANNER to read more than 31 byte of advertising data

Vidar Berg — Mon, 13 Jan 2020 13:41:32 GMT

Hi,

You're right. I forgot that the UART central example does active scanning by default. But since it's already enabled, you should be getting adv. report events with the ble_gap_adv_report_type_t::scan_response bit set as well. Can you check if you get any scan responses? Just remember that you cannot continue execution after hitting a breakpoint as that will likely cause the Softdevice to trigger an assertion.

RE: BEACON SCANNER to read more than 31 byte of advertising data

VIGNESH C — Fri, 10 Jan 2020 09:37:47 GMT

Hi Vidar Berg,

Thanks for the replay. I have checked the "scan_init()" function, and the ble_gap_scan_params_t::active bit

Actually the active bit is set to 1, by default.

But still i'm not receiving more than 30 bytes of beacon data.

RE: BEACON SCANNER to read more than 31 byte of advertising data

Vidar Berg — Thu, 09 Jan 2020 12:24:50 GMT

Hello,

Please make sure the ble_gap_scan_params_t::active bit is gets set to '1' when you initialize the scanner (ble_gap_scan_params_t). This will make the scanner issue a scan request to receive the scan response packet, which probably contains the remaining sensor data.

This tutorial here explains a bit about how and why scan responses are used: https://devzone.nordicsemi.com/nordic/short-range-guides/b/bluetooth-low-energy/posts/ble-advertising-a-beginners-tutorial