Security getting tiggered

[Zach]

I am using the ble_app_uart code from SDK 6.0 on my custom PCB with a nrf51822. I am comparing it's functionality with a PCA10004. Both are running the exact same code. I'm also using both the Master Control Panel and an iphone 5S (running nrf UART) to interact with them.

I am getting different results between my PCB and the PCA10004 and I am trying to track down the issue.

Here's what is happening... using the custom PCB and the iphone nrf UART app, I can connect to the device, but during that process a BLE_GAP_EVT_SEC_INFO_REQUEST event (seen using the debugger) which errors out with "No keys found for this device" . After that, any attempts to send data from the iphone to the app fail to generate the nus_data_handler call.

If I do the same test with the PCA10004 and the iphone, I never see the BLE_GAP_EVT_SEC_INFO_REQUEST event and data is transferred back and forth just fine.

If I try my custom PCB and use the Master Control Panel software to connect, do a service discovery, and then send some data, I never get the BLE_GAP_EVT_SEC_INFO_REQUEST and the data is transferred successfully.

So, there is something going on between my custom board and the iphone that is triggering this security request. I have tried turning bonding off. I've verified that in the gap init function, we are using BLE_GAP_CONN_SEC_MODE_SET_OPEN, which I'm assuming to mean that there is no security/encryption.

Any thoughts/suggestions would be helpful.

Thanks.

[Zach]

Nordic support figured it out and I though I would post here for any future searches... Turns out that my custom board was showing up under paired devices on my iphone (Settings->Bluetooth->Devices). I assume this is because it bonded with it. So even though I disabled bonding on the nrf51822 side, the phone still had bonding info for this device and was asking for security info, which triggered the problem.

[Petter Myhre]

Thank you for answering your own question.