<error> ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

JustinLee — Mon, 08 Jan 2018 08:17:29 GMT

This issue is related to GAP EVENT LENGTH. In NUS example in the nRF5 SDK v14, NRF_SDH_BLE_GAP_EVENT_LENGTH is 3 and it's not proper value. Please change it from 3 to 5 or 6.

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

ajay — Mon, 08 Jan 2018 07:47:28 GMT

It is working for me on nRF5_SDK_14.2.0_17b948a

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

Hung Bui — Tue, 19 Dec 2017 14:31:22 GMT

Most likely because we handle event BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST in both nrf_ble_gatt.c module and in main.c

In other example we don't handle BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST event in main.c so they are fine, but not in ble_app_uart where we don't use peer manager.

Comment out the handle of BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST in ble_evt_handler() in main.c should fix the issue.

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

Hieu — Fri, 01 Dec 2017 07:40:31 GMT

I just ran into this and want to report that the same issue still presents on SDK v14.2.0. I am working on adding mesh to it, but I don't think that is relevant, as I kept all other BLE functionality the same.

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

Petter Myhre — Wed, 08 Nov 2017 14:13:16 GMT

Yes, if that is a modification you want to do to the ble_app_uart example I suggest that you make a separate question.

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

schef — Wed, 08 Nov 2017 14:09:53 GMT

Is it possible to get rid of the error and to stay on HIGH MTU? If i stay on high mtu and leave the error what would be the downsides?

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

Petter Myhre — Wed, 08 Nov 2017 13:47:56 GMT

Depends on what you mean by high speed. It limits the amount of data in each packet to 20 bytes, so you will have more overhead compared to have a larger MTU.

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

schef — Wed, 08 Nov 2017 12:55:56 GMT

If i set NRF_SDH_BLE_GATT_MAX_MTU_SIZE 23 then i don't have the ability for high speed. Is this true?

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

Petter Myhre — Wed, 08 Nov 2017 12:52:47 GMT

Bad error? What do you mean? Have you seen my answer below? Did you make the modifications?

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

schef — Wed, 08 Nov 2017 12:45:32 GMT

Is ti a bad error? How can i set my device to have maximum MTU and not to have this error?

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

Petter Myhre — Thu, 07 Sep 2017 07:06:26 GMT

Yes. Of course. Sorry.

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

erltot — Wed, 06 Sep 2017 15:32:46 GMT

gatt_init looks like this:

/**@brief Function for initializing the GATT library. */
void gatt_init(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, 64);
    APP_ERROR_CHECK(err_code);
}

I'm sure you mean to change

err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, 64);

err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, BLE_GATT_ATT_MTU_DEFAULT);

which yields following output in jlink

 0> <info> app: Connected
 0> <info> app: Data len is set to 0x14(20)

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

Petter Myhre — Wed, 06 Sep 2017 15:04:00 GMT

I'm sorry, I overlooked that you were using the unmodified example. This seems like a bug to me.

Inside gatt_init(), if you change

err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, 64);

err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, BLE_GATT_ATT_MTU_DEFAULT);

and inside sd_config.h, change

NRF_SDH_BLE_GATT_MAX_MTU_SIZE 247

NRF_SDH_BLE_GATT_MAX_MTU_SIZE 23

Edit 22.01.2018

This should be fixed in SDK 15.0.0

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

pbn4 — Wed, 06 Sep 2017 12:23:48 GMT

I think this is the same problem

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

erltot — Wed, 06 Sep 2017 12:11:23 GMT

See updated question. -> So NULL is sendt to p_dl_limitation? I dont mean to be ignorant - but I don't understand why I get this error or how to change ATT MTU or why I get this error, again this shows up just from compiling and running the ble_app_uart peripheral example and connecting with nrf connect on windows or android, or ios.. m_ble_nus_max_data_len is set to BLE_GATT_ATT_MTU_DEFAULT - 3; at the beginning of main.c, which should be 20, not 61 ??

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

Petter Myhre — Tue, 05 Sep 2017 18:05:23 GMT

p_dl_limitation is an argument to sd_ble_gap_data_length_update(). It might give a pointer to why you get the error, if the event length is too short, if the max ATT MTU is too small.

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

erltot — Tue, 05 Sep 2017 15:40:05 GMT

Where do I inspect p_dl_limitation? I'm not sure I understand what you mean.

I have not changed these settings from the ble nus example, so should be fairly simple to reproduce.

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

Petter Myhre — Tue, 05 Sep 2017 11:24:36 GMT

0x13 is NRF_ERROR_RESOURCES - The requested parameters can not be accommodated. Inspect p_dl_limitation so see where the limitation is.

What parameters did you request? What are the values in p_dl_limitation? What is the max ATT MTU you have set? What kind of event length have you set?

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

erltot — Mon, 04 Sep 2017 14:21:04 GMT

Nothing yet

RE: ble_gatt: sd_ble_gap_data_length_update() (request) on connection 0x0 returned unexpected value 0x13.

pbn4 — Mon, 04 Sep 2017 13:53:45 GMT

I also met this error, any solutions?