Reading a characteristic does not generate a BLE event

RE: Reading a characteristic does not generate a BLE event

only1chi — Fri, 03 Jul 2020 15:53:26 GMT

I figured it out. I understand now what you're saying.
I was using sd_ble_gatts_value_set() function to handle the event when I should have been using sd_ble_gatts_rw_authorize_reply()

Thanks

RE: Reading a characteristic does not generate a BLE event

only1chi — Fri, 03 Jul 2020 15:22:47 GMT

Hi Hung,

Thanks for your answer. I had done the exact same thing before, but I haven't seen the event.
Where in the application would I see the event? Which of the handlers?

Also in the file vpe_ble.c, there is an event handler which looks for

BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST

I never see that event get triggered.

Could you point me to the event handler you're referring to?

RE: Reading a characteristic does not generate a BLE event

Hung Bui — Fri, 03 Jul 2020 14:56:55 GMT

It seems a little bit different from the initial code you quoted in the original question. In the project in the .zip you sent you used the ble_srv library to initialize the characteristic.
I noticed that you used : add_char_params.p_user_descr->is_defered_read = 1; This is the property for the user descriptor, not the characteristic value itself. You should use :

add_char_params.is_defered_read=1;

instead.

After changing that, i can see the read event in the log: ble_vpe: Read Event. conn_handle: 0

It doesn't seem you have handle the reply/confirmation for the read. You would need to implement sd_ble_gatts_rw_authorize_reply() in on_read()

RE: Reading a characteristic does not generate a BLE event

only1chi — Fri, 03 Jul 2020 13:50:56 GMT

Hi Hung,

I've attached my project.

Thank you.

devzone.nordicsemi.com/.../sts_2D00_vector_2D00_pump_2D00_emulator.zip

RE: Reading a characteristic does not generate a BLE event

Hung Bui — Fri, 03 Jul 2020 08:57:21 GMT

Hi Only1chi,

Could you send your full project so we can test here ? Or if you can create a minimum project that I can run on nRF52 DK here it would be great.
When you don't get a read event, what do you see on the phone's side ?

RE: Reading a characteristic does not generate a BLE event

only1chi — Thu, 02 Jul 2020 17:30:19 GMT

I also checked it out with nrf Connect, and all the characteristics show up properly. But I still don't get a READ event.

RE: Reading a characteristic does not generate a BLE event

only1chi — Thu, 02 Jul 2020 17:22:29 GMT

Currently I get all the write events, however, setting
attr_md.rd_auth = 1

causes it to stop generating WRITE events, in addition to not generating a READ event.

RE: Reading a characteristic does not generate a BLE event

only1chi — Thu, 02 Jul 2020 16:56:53 GMT

Hi Hug,

I'm using SDK v17.
The events do not appear on peer's side.

RE: Reading a characteristic does not generate a BLE event

Hung Bui — Thu, 02 Jul 2020 13:54:31 GMT

Hi Only1chi,

Could you let me know which SDK version you are using and with which Softdevice ?

I did a quick test here with the NUS service in SDK v14.2 and it worked fine for me.

When you don't see the read event, can you actually get the characteristic's value on the peer's side ?

devzone.nordicsemi.com/.../ble_5F00_nus.c