Bluetooth communication development

RE: Bluetooth communication development

Kenneth — Wed, 22 Jan 2020 09:10:12 GMT

A handle value of 2066 sounds incorrect, these handles are typically sequentially and chronologically starting from a low value close to 0 (only offset by some of the GAP services that is in the softdevice).

Best regards,
Kenneth

RE: Bluetooth communication development

ILCD — Wed, 22 Jan 2020 02:17:43 GMT

Hello!

Thank you very much for your reply.

Here's a question about CCCD handle.

We tried to read the blood pressure measured by through Bluetooth.The handle value of CCCD is 2066, and the connection handle value is 0, which is called back through the callback function.

However, it is not possible to confirm that the value of CCCD handle value is correct,

Can you give us some instructions.

Best regards,

ILCD-CHINA

RE: Bluetooth communication development

Kenneth — Mon, 20 Jan 2020 08:38:19 GMT

Not exactly sure what is the problem here. But I suggest to check out:
https://devzone.nordicsemi.com/nordic/short-range-guides/b/bluetooth-low-energy/posts/ble-characteristics-a-beginners-tutorial

You can find a reference of all GATT client/server message sequence flow charts here: https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v7.0.1/s132_msc_overview.html

RE: Bluetooth communication development

ILCD — Fri, 17 Jan 2020 02:01:41 GMT

Hello!

Thank you very much for your reply.

You said above: refer to the existing client-side processing, refer to the “message sequence charts ”to call the callback function. We've done that, but communication with other Bluetooth devices has failed.

Note down the process of client application development ：

① The APP find service UUID(such as, UUID:180A for Device information,UUID:1810 for Blood pressure measurement),this step is OK.

②The APP write the CCCD,Enable CCCD type is BLE_GATT_HVX_INDICATION.And the SDK API return is Success.

③The callback function on the client side will pass event “BLE_GATTC_EVT_HVX”，Get another Bluetooth device's blood pressure measurement.

Through log output and debug check, it is found that there is no problem in the program processing flow of the client.（We programmed the client application to read the blood pressure measurement. ）But the client didn't receive the event “BLE_GATTC_EVT_HVX”.Debug another blood pressure measurement device, the blood pressure measurement results have been output.Only the client side of nrf52832 did not receive the data.

Here are a few questions:

Whether the nRF5 SDK supports reading of blood pressure measurements on the client side,Because from the example provided by Nordic, only blood pressure measurement is used as the application of the server.

From the development process of the client side that has been described, what are the problems, please put forward.

Best regards,

ILCD-CHINA

RE: Bluetooth communication development

Kenneth — Thu, 16 Jan 2020 08:44:35 GMT

Hi,

You should find a few client implementations for other BLE applications in the nRF5 SDK, you need to use those as reference/guidance on how to implement this to handle blood pressure. In addition to the nRF5 SDK documentation, I would recommend to check out the message sequence charts that explain what BLE callback events are generated from the softdevice, and how the application can handle them (note that most BLE events are handled by including sdk modules such as peer manager for bonding, advertisement module for advertisement, and gatt module for MTU/DLE exchange). Though you can still find the message sequence charts useful for debugging and understanding:

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v7.0.1/s132_msc_overview.html?cp=4_5_2_1_1

Best regards,
Kenneth

RE: Bluetooth communication development

ILCD — Thu, 16 Jan 2020 01:03:26 GMT

Hello!

Thank you for your reply.

However, there are still grease sticks and problems, which need your reply.

In the example you told me (sdk16.0.0), only on the BLE Peripheral side have the Blood Pressure example.

In our development work,We want to use The Bluetooth MCU (nrf52832) as BLE Central.To receive another Bluetooth device's blood pressure measurement. We tried to program a ble central program to receive blood pressure measurements, but it failed.

But in nRF5 SDK v16.0.0 the list Bluetooth low energy examples in BLE Central ,There is no example of blood pressure measurement as client.

Can you provide an example.

In addition, there is no explanation about the communication mode of " INDICATION" in the example you gave us.

You can provide some examples about it.

Best regards,

ILCD-CHINA.

RE: Bluetooth communication development

Kenneth — Wed, 15 Jan 2020 12:15:04 GMT

Hi,

You are right that there is not a full list of BLE examples for both peripheral and central implementations. You can find the list of examples here: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v16.0.0/examples_ble.html?cp=7_1_4_2

In this case you can for instance find that the https://infocenter.nordicsemi.com/topic/sdk_nrf5_v16.0.0/ble_sdk_app_blinky_c.html is example for a central BLE device with a client application. The corresponing peripheral example is the https://infocenter.nordicsemi.com/topic/sdk_nrf5_v16.0.0/ble_sdk_app_blinky.html example with a server application.

If you look at those two examples you hopefully will get some guidance on how to make a client application to handle the https://infocenter.nordicsemi.com/topic/sdk_nrf5_v16.0.0/ble_sdk_app_gls.html example project.

Best regards,
Kenneth

RE: Bluetooth communication development

ILCD — Tue, 14 Jan 2020 05:26:22 GMT

sorry！

i didnt get the answer!

RE: Bluetooth communication development

ILCD — Tue, 14 Jan 2020 04:58:34 GMT

There is no client program for blood pressure measurement in SDK (15.2.0),

Please provide.