Unexpected return value when calling sd_ble_gatts_hvx() when notifications are not enabled

RE: Unexpected return value when calling sd_ble_gatts_hvx() when notifications are not enabled

AndreasF — Tue, 29 Oct 2019 07:47:48 GMT

Hi.

The error you see is not BLE_ERROR_NOT_ENABLED, but BLE_ERROR_GATTS_SYS_ATTR_MISSING.

We can first take a look at the math for the two different definitions:

NRF_ERROR_STK_BASE_NUM = 0x3000 in the SDK

BLE_ERROR_NOT_ENABLED = NRF_ERROR_STK_BASE_NUM + 0x001 = 0x3001

BLE_ERROR_GATTS_SYS_ATTR_MISSING = NRF_GATTS_ERR_BASE + 0x001 = NRF_ERROR_STK_BASE_NUM + 0x400 + 0x001 = 0x3401

Also checked that this is the value by debugging:

Can also see that sd_ble_enabled returns 0x8 which is invalid state (NRF_ERROR_INVALID_STATE):

So I'm pretty confident that the error is BLE_ERROR_GATTS_SYS_ATTR_MISSING, and the solution to handle this error is described here.

Best regards,

Andreas

RE: Unexpected return value when calling sd_ble_gatts_hvx() when notifications are not enabled

AndreasF — Mon, 28 Oct 2019 13:58:06 GMT

Hi.

I've give you a reply tomorrow, I've been quite busy today, sorry.

Best regards,

Andreas

RE: Unexpected return value when calling sd_ble_gatts_hvx() when notifications are not enabled

m.wagner — Fri, 25 Oct 2019 12:57:37 GMT

Hi Andreas,

[quote userid="73423" url="~/f/nordic-q-a/51000/unexpected-return-value-when-calling-sd_ble_gatts_hvx-when-notifications-are-not-enabled/204278"]Could you help me reproduce the issue? Perhaps share your project? I can make the ticket private if you like :-) [/quote]

I finally managed to reproduce the issue for you. I don't even have to provide code, the Nordic SDK provides the example directly.

Steps to reproduce:

Download SDK 15.2.0
Flash the associated softdevice onto an nRF52 DK (S132 v6.1.0)
Build and flash the exmple "ble_peripheral\ble_app_blinky"

Start the debugger and set a breakpoint in main.c, function button_event_handler(), in the if-block on line 497:

if (err_code != NRF_SUCCESS &&
                err_code != BLE_ERROR_INVALID_CONN_HANDLE &&
                err_code != NRF_ERROR_INVALID_STATE &&
                err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)

Connect to the peripheral with e.g. nRF Connect.
Press Button 1 on the nRF52 DK.
When you inspect the contents of the err_code variable in the debugger, you will notice that the value reads 0x3401, which corresponds to BLE_ERROR_NOT_ENABLED and is documented in ble_err.h as indicating that "sd_ble_enable has not been called."

Best regards,

-mike

RE: Unexpected return value when calling sd_ble_gatts_hvx() when notifications are not enabled

AndreasF — Wed, 21 Aug 2019 13:18:16 GMT

Hi.

It's the same check performed for v6.1.1 as for v5.0.0, so it should not be different as far as I know.

Best regards,

Andreas

RE: Unexpected return value when calling sd_ble_gatts_hvx() when notifications are not enabled

m.wagner — Wed, 21 Aug 2019 12:49:58 GMT

Hi,

Unfortunately I haven't gotten around looking into it more closely, but I noticed that I mixed up two projects. This issue specifically concerns S132 v5.0.0 and not v6.1.1 as originally mentioned!

Also, the product has actually been in production for some time and is not still in development.

Regards,

-mike

RE: Unexpected return value when calling sd_ble_gatts_hvx() when notifications are not enabled

AndreasF — Thu, 15 Aug 2019 11:12:07 GMT

Hi.

Could you help me reproduce the issue? Perhaps share your project? I can make the ticket private if you like :-)

Best regards,

Andreas

RE: Unexpected return value when calling sd_ble_gatts_hvx() when notifications are not enabled

m.wagner — Thu, 15 Aug 2019 09:09:22 GMT

[quote userid="73423" url="~/f/nordic-q-a/51000/unexpected-return-value-when-calling-sd_ble_gatts_hvx-when-notifications-are-not-enabled/204197"]Have you enabled the SoftDevice?[/quote]

As I mentioned in my initial question, the softdevice is enabled. Even a BLE connection has been established at the point that issue arises, so the behaviour of this call is indeed not as documented.

I just assume that there was a simple mishap when implementing the function, "BLE_ERROR_NOT_ENABLED" by itself does sound like the right error to return when notifications are "not enabled"... ;-)

RE: Unexpected return value when calling sd_ble_gatts_hvx() when notifications are not enabled

AndreasF — Thu, 15 Aug 2019 06:57:03 GMT

Hi.

Have you enabled the SoftDevice? BLE_ERROR_NOT_ENABLED will only be returned if the SoftDevice is not enabled.

Best regards,

Andreas