nrf connect app problem

RE: nrf connect app problem

Amanda Hsieh — Tue, 04 May 2021 08:25:15 GMT

Hi,

Sorry for the delay. I cannot reproduce the issue on nRF52832DK. Here is my test project devzone.nordicsemi.com/.../ble_5F00_app_5F00_template_5F00_267175.zip. If you want to test on nRF52832DK, you can place it under nRF5_SDK_17.0.2_d674dde\examples\ble_peripheral. After disconnection, both two "Characteristic A" and "Characteristic B" can receive data.

-Amanda H.

RE: nrf connect app problem

zero — Wed, 28 Apr 2021 09:16:16 GMT

Hi，

Create a private service. There are two features under this service: "Characteristic A" and "Characteristic B" (the configuration of the two Characteristic on the device is the same)
The following tests were carried out in nRF Connect for Android:
1. Open the notify of "Characteristic A" and the notify of "Characteristic B".
2. Send data to "Characteristic A" and "Characteristic B", and nRF Connect for Android can receive the data.
3. Disconnect and reconnect the device.
4. The connected device does not perform the enable operation of notify, and the device sends data to "Characteristic A" and "Characteristic B"
Result: "Characteristic A" can receive data, "Characteristic B" cannot receive data
Question: Why can't for "Characteristic B" receive data ?

RE: nrf connect app problem

Aleksander Nowakowski — Mon, 26 Apr 2021 13:05:34 GMT

This is not about Android and iOS being different. Saving state of CCCD for bonded devices is a feature of nRF Connect for Android, it's a feature we implemented to be more "complaint with spec". In nRF Connect for iOS it is not possible to implement, as the API does not expose the bonding state to the connected device. So the app does not know whether the device is bonded, or not. And the system does not cache CCCD for remote characteristics, as far as I know.

RE: nrf connect app problem

zero — Tue, 20 Apr 2021 07:49:53 GMT

Hi，

Can you analyze why ios and Android are different? Or is there any article about the different descriptions of Bluetooth connection between ios and Android?

RE: nrf connect app problem

Aleksander Nowakowski — Mon, 12 Apr 2021 09:35:27 GMT

Hello,

This is not a "phenomenon". Your device is bonded, which means both client and server can store the value of Client Characteristic Configuration Descriptor (CCCD), so that after reconnection enabling notifications/indications is not required. nRF Connect for Android does it. It cannot verify whether the other side in fact also has stored CCCD value (without reading CCCD value), but with Nordic SDKs it should be true. You may always read the value of CCCD to update the value.

Had your device not been bonded, you would not have had this "phenomenon".

Also, another fun fact, if nRF Connect receives a notification/indication from a characteristic which had the value set to "disabled", is assumes they were actually enabled, and changes the CCCD state accordingly. For that, nRF Connect calls setCharacteristicNotification with value true for each characteristic with NOTIFY/INDICATE properties (you can see it in the log). This does not enable notifications remotely, but notifies Android system, that the local client is interested in receiving updates on those attributes.

RE: nrf connect app problem

Amanda Hsieh — Mon, 12 Apr 2021 09:07:12 GMT

Hi Zero,

I can reproduce the phenomenon if the phone bonded with the HRS. Because the device is bonded, the CCCD state is saved. After deleting the bond info, you could see it work as the ios app.

-Amanda H.

RE: nrf connect app problem

zero — Mon, 12 Apr 2021 06:34:06 GMT

Hi，

HUAWEI Mate 30 pro,

XIAOMI 11 pro,

Samsung Galaxy S21.

RE: nrf connect app problem

Amanda Hsieh — Mon, 12 Apr 2021 06:17:36 GMT

Do you try another android phone?

What is the android phone you are using?

-Amanda H.

RE: nrf connect app problem

zero — Mon, 12 Apr 2021 06:05:24 GMT

Hi，

Yes, that's how I do it.

RE: nrf connect app problem

Amanda Hsieh — Mon, 12 Apr 2021 05:58:34 GMT

Hi,

Sorry for the delay.

Did you try to disconnect, refresh device cache, and then reconnect?

-Amanda H.

RE: nrf connect app problem

zero — Thu, 01 Apr 2021 06:05:31 GMT

Hi，

How to solve this phenomenon?

RE: nrf connect app problem

zero — Tue, 30 Mar 2021 11:54:08 GMT

Hi，

Based on the Heart Rate Application routine of sdk15.3, after disconnecting, refresh the device cache and then reconnect, the same phenomenon occurs.

RE: nrf connect app problem

Amanda Hsieh — Tue, 30 Mar 2021 11:07:57 GMT

Try to disconnect, refresh device cache, and then reconnect.

Android phones might still keep the casched data and need to fresh.

Please note that due to the Easter holiday, we're low on staff, so somewhat lower response times must be expected until April 6th. Sorry about the inconvenience.

-Amanda H.

RE: nrf connect app problem

zero — Tue, 30 Mar 2021 09:32:30 GMT

Hi，

I just did a "disconnect"/"reconnect" operation.
I want to know why ios does not have this phenomenon, but Android phones have this phenomenon?

RE: nrf connect app problem

Amanda Hsieh — Tue, 30 Mar 2021 09:16:02 GMT

Hi,

Does the refresh device cache work? If so, it might the phone has chosen to update the cached data. The phone will cache the information it has on a device (name, Bluetooth address, etc).

Please note that due to the Easter holiday, we're low on staff, so somewhat lower response times must be expected until April 6th. Sorry about the inconvenience.

-Amanda H.

RE: nrf connect app problem

zero — Tue, 30 Mar 2021 09:07:09 GMT

Hi，

What is the cause of this phenomenon?

RE: nrf connect app problem

Amanda Hsieh — Tue, 30 Mar 2021 08:57:54 GMT

Hi,

Try to refresh device cache after disconnection.

-Amanda H.

RE: nrf connect app problem

zero — Mon, 29 Mar 2021 01:03:38 GMT

Hi,

Heart Rate Application is the same phenomenon

devzone.nordicsemi.com/.../786f07f904d1426052df79d756b9f942.mp4

RE: nrf connect app problem

Amanda Hsieh — Fri, 26 Mar 2021 13:12:47 GMT

Hi,

Are you able to test Heart Rate Application? Do you also see the same phenomenon?

If not, please refer to the example to check and debug the code.

-Amanda H.