nus_data_handler from android app -> nrf52840

[jawadk]

Hi all,

I am using my android ble application , but I don't manage to receive data sent from the application to the device ( nrf52840 )

I am using the ble_app_uart example from nRF5_SDK_15.2.0 with the latest softdevice 6.1.1

when i am using my app the nus_data_handler not called with BLE_NUS_EVT_RX_DATA as it should (not called at all).

but the ble_evt_handler is called , can't find the data sent in the ble event struct ( ble_evt_t const * p_ble_evt)

when I am using NRF_connect application , the nus_data is called with BLE_NUS_EVT_RX_DATA  ... 

and I can find the data also in the ble event struct when the ble_evt_handler is called.

can you advice why my application can't trigger the nus_data_handler  on the nrf52840 !?

or the opposite why my device nrf52840  can't manage to detect and call the  nus_data_handler  with BLE_NUS_EVT_RX_DATA ?

[Simon]

I am not too familiar with android app development, but I have a recommendation for an easier approach: 

• Visit Nordic Semiconductor's github, and use some of the examples there as a starting point
  • The Android-nRF-Toolbox app is a smart choice, as it supports connection to the NUS service
• Use time to understand the code, including how the application sends data to the device (nRF52840)
• Copy the application and strip it down to form your own solution, while continuously testing it and making sure it works as intended

Best regards,

Simon

[jawadk]

Hi Simon,

If i had a BLE application that worked perfectly with another company SOC ( not nordic)

And now I am trying to use it with nrf52850 SOC, do I have to do some changes to the application ? If yes what should be changed ?

I am asking cause my application worked with another ble device and now with nordic module it’s not working

again do the application not managed to trigger a ble_nus_evt_rx_data ?

or my nrf52840 can’t detect it ?

note : my device managed to communicate perfectly with nrf-connect app, nrfuart app and other applications, besides my app can communicate with another advertizing application on another mobile device and i can see the data sent from my app.

[awneil]

The whole point of standards like BLE is that they are totally independent of the underlying hardware.

Therefore, if your nRF52840 implements exactly the same BLE services & profiles as the "other company" SoC, then no changes would be required to the Android App.

However, the Nordic UART Service - NUS - is proprietary to Nordic (the clue is in the name!), so it is unlikely that the "other company" SoC will have that service.

jawadk said:

note : my device managed to communicate perfectly with nrf-connect app, nrfuart app and other applications,

So there is something wrong or missing in your app!

As Simon said, you need to study what those Nordic apps are doing - and make sure that your app is doing the same.

See this post for debugging BLE on Android:

http://www.argenox.com/bluetooth-low-energy-ble-v4-0-development/library/ultimate-guide-to-debugging-bluetooth-smart-ble-products/

[jawadk]

Thanks for your reply ,

of course the service uuid and the charactertic write id and read id was changed to the nus service from the app too .

my app manage to receive data fron the nrf52840 , but the other communication direction don’t work , there is no ble_evt_rx_data received .

thanks for the help

JawadK

[Simon]

Did you resolve the issue?

[jawadk]

Yes I resolved the issue.

Added some delay in the app after the connection with the device, right before turning on the characteristics, that worked.

Thanks for the help.

Regards

Jawad