Guidance on Implementing Concurrent Central and Peripheral Roles for nRF52832 Using nRF5 SDK 17.0.2

[siltvm]

Hi,

We are currently planning to start a project using the nRF52832 as our controller, SEGGER Embedded Studio version 5.42a as the IDE, and nRF5 SDK version 17.0.2 as our SDK. Our requirement is to have an nRF52832 device that behaves as both a central and peripheral.

Initially, the nRF52832 will act as a peripheral, allowing it to connect with the nRF Connect app. After this connection is established, the nRF52832 needs to function as both a central and a peripheral simultaneously. Other nRF52832 peripheral devices will be present, and these peripherals will connect to the central nRF52832. The central device should send information about the connected peripheral devices, such as MAC IDs and advertising names, to the app.

When the app sends BLE UART data specifying a particular destination device, this data should be forwarded to the corresponding nRF52832 peripheral device through the nrf52832 central device (GATEWAY) .

Project Details:

• SDK: nRF5 SDK 17.0.2
• IDE: SEGGER Embedded Studio 5.42a
• Controller: nRF52832

Thank you for your support.

Best regards,
SILTVM

[Hung Bui]

Hi, 
Please take a look at \examples\ble_central_and_peripheral\experimental\ble_app_hrs_rscs_relay example. It does almost exactly the same what you described. 

[siltvm]

Hung Bui , in the given example code how can i add nordic uart service , and scan and connect nordic uart service based devices . is there any tutorial for that ? 

[Hung Bui]

Hi, 
My suggestion is to get familiar with the uart sample code. After you get to know how to include the UART service in the code, then you should be able to modify the ble_app_hrs_rxs_relay to remove the HRS service and add NUS service instead. 

Please be aware that the nRF5 SDK is deprecated and it's suggested to use nRF Connect SDK instead. You can find central&peripheral sample in the nRF Connect SDK as well as the NUS service in nRF Connect SDK. 

[siltvm]

Hung Bui ,

We have decided to add the Nordic UART service to the ble_app_hrs_rscs_relay example project. Before doing that, I am testing the code based on the link you provided.

I flashed the ble_app_hrs_rscs_relay example project onto one development board and the ble_app_rscs example project from the BLE peripheral directory onto another development board. After flashing, the ble_app_hrs_rscs_relay-flashed board successfully connected with the ble_app_rscs-flashed board, and it sent speed data to the ble_app_hrs_rscs_relay board, which I could see in the logs. However, when I try to connect to the ble_app_hrs_rscs_relay-flashed board using the nRF Connect APK, I am unable to connect. The logs show a warning.

What could be the possible reason for this issue?

development board  :-  nrf52832 pca10040 

<info> app: Peripheral connected

<info> app: Speed      = 896

<info> peer_manager_handler: Connection security failed: role: Peripheral, conn_handle: 0x2, procedure: Encryption, error: 4102

<warning> peer_manager_handler: Disconnecting conn_handle 2.

<info> app: Fast advertising.

<info> app: Peripheral disconnected. conn_handle: 0x2, reason: 0x16

[Hung Bui]

Hi,

It's most likely  because that one of the sides (phone or ble_app_hrs_rscs_relay board) has the bond information from previous pairing between them when the other doesn't. Please try to erase the full chip on the nRF52 board (nrfjprog --eraseall) and try to find if the device is in the bonded list on Bluetooth on the phone, click Forget this device. 
You can take a look at this ticket: devzone.nordicsemi.com/.../peer_manager_handler-connection-security-failed-role-peripheral-conn_handle-0x0-procedure-encryption-error-4102