Disconnections between iOS 8-10 and RedBear BLE Nano V1.5

[mike_knapnok]

We're having troubles with BLE connection between iOS 8-10 devices (iPad Pro, iPad Air 2, iPad Mini 3, iPhone 7, iPhone 6) and RedBear BLE Nano V1.5 32KB boards (with Nordic nRF51822 SoC on board).

The devices connect and communicate fine at first. But in a random point within 5 minutes, a disconnection is detected on the iOS side. The error message says:

Error Domain=CBErrorDomain Code=6 "The connection has timed out unexpectedly."

The Nordic boards do not get any callback about it. The problem does not occur with our Android tablets (Nexus 9) in place of iOS.

Similar questions from this forum:

1. devzone.nordicsemi.com/.../ and devzone.nordicsemi.com/.../

• as advised, we tried to change the PPM value in SOFTDEVICE_HANDLER_INIT to NRF_CLOCK_LFCLKSRC_XTAL_250_PPM, or even 500. It didn't help.

2. devzone.nordicsemi.com/.../

• we removed the NVIC_SystemReset(); line from the app_error_handler, but our Arduino Serial Monitor still shows no sign of error or crash - it just stops receiving messages.

[Hung Bui]

Could you check what is the disconnect reason code when you receive BLE_GAP_EVT_DISCONNECTED event ?

Do you have a Nordic nRF5 board that you can use to capture a sniffer trace ? It would be very useful to analise what cause the disconnection.

[mike_knapnok]

Thanks for your comment, Hung Bui.

• Unfortunately, I never get any callback on the Nordic side... Only the iOS detects the disconnection.
• We only have the RedBear Nano boards (built around nRF51822). Do you know if it is possible to run the sniffer on them, or do I need the proper Evaluation/Development kit? So far I am getting the Keyboard input error [Error 2] when I try to re-program them (ctrl+R) with the ble-sniffer-win exe

[Hung Bui]

I think the Redbear maker mentioned about how to configure it to work as the sniffer here. You need to connect the UART pins the same as what we have on our DK/dongle.

There should be a callback on Nordic side, the connection can't remain in connection all the time. I suspect the chip got reset/assertion ?