Connection problems with Android 7 and SDK12.1

[janR]

We have problems when connecting to a device running softdevice S132 version 3.0 with a tablet running Android 7.0.

When we use tablet and nRF Connect, we get Error 8 (0x8): GATT CONN TIMEOUT and Error 133 (0x85): GATT ERROR and disconnect. Softdevice asserts with id = 1 and pc = 0x0001A216 when we try to connect.

With Android 6.0 there is no problem.

Tablet is a Samsung SM-T580 running Android 7.0

Problem is reproducable with ble_app_hrs_freertos example project from SDK12.1

Is this a known problem, and is there any way around it?

Regards, Jan

[janR]

Same problem with S132 3.1.0, above changes and ble_app_hrs

[Sigurd]

The data_len_ext_set() function should have done the trick. Try to call it right before you start advertising, i.e.

// Start execution.
NRF_LOG_INFO("Heart Rate Sensor Start!\r\n");
application_timers_start();
data_len_ext_set();
advertising_start();

[Sigurd]

If it's still not working, you should try to see if you have the same issue with SDK 14.0 and S132 v.5.0.0

[janR]

Moving data_len_ext_set() did not help.

I have already tried SDK14, and there is no problems with this. Tablet connects fine with ble_app_hrs_freertos example project from SDK14.

But it is normally a pain to migrate to a new main SDK, i.e. from SDK12 to SDK14...

[Sigurd]

Ok. Let's try to disable the DLE feature completely.

Add

err_code = sd_ble_opt_set(BLE_GAP_OPT_DLE_DISABLE, &opt);
APP_ERROR_CHECK(err_code);

in the buttom of the data_len_ext_set() function.

data_len_ext_set() should then look like this:

void data_len_ext_set(void)
{
    ret_code_t err_code;
    ble_opt_t  opt;

    memset(&opt, 0x00, sizeof(opt));

    opt.gap_opt.ext_len.rxtx_max_pdu_payload_size = 0;
    
    

    err_code = sd_ble_opt_set(BLE_GAP_OPT_EXT_LEN, &opt);
    APP_ERROR_CHECK(err_code);
    
    err_code = sd_ble_opt_set(BLE_GAP_OPT_DLE_DISABLE, &opt);
    APP_ERROR_CHECK(err_code);
}