ios reconnect keyboard after bonds erased,conn_sec_failed

[jiaqing_liuliu]

i use the keyboard project, bond and pair the iphone7(ios11.2), the iphone display is connected,ok, then i reset the keyboard and erase bonds, the iphone display disconnected then connected, but this link can not work, is a kind of false connections. i can see the PM_EVT_CONN_SEC_FAILED in the log message, how to change the keyboard code for iphone display is still disconnected when i reset the keyboard and erase bonds.

i try the android5.1.1, when i reset the keyboard and erase bonds, the android display is disconnected, if android want to connect the keyboard ,need new bond and pair , i think this process is right

[run_ar]

If you delete the bond information on the the Peripheral but not on the phone you should see get a error event. Note that iOS will reconnect automatically to a known/bonded HID device and try to re-establish the bond. So you will get the failed event. Not sure what the behavior is for the Android 5.1.1 Handset you are using, but sounds like it has a security issue... Regardless it is hard to say exactly what is happening without looking at sniffer logs.

[jiaqing_liuliu]

2017121502android.psd 2017121502ios.psd

hi run_ar ,thank you for your reply, i get the sniffer logs by Packet Sniffer,the catch chip is cc2540, please see the attachment , 2017121502android.psd is android5.1.1 link keyboard 2017121502ios.psd is ios11.2 link keyboard. the step is that android bond and pair keyboard ,connect ok,then reset the keyboard and erase bonds, then android disconnect with keyboard. the ios11.2 link keybord step is same, but the ios disconect then connect the keyboard , i don't know the sniffer log files is valid , this is my first time to catch the sinffer log message.

In addition, android5.1.1 link the keyboard, i find the log message in the end , when android find a connnect security failed event ,then send a disconnect event to keyboard ,so the link is disconnect,then keyboard go to fast advertising . ios11.2 link the keyboard, i find in the end, a connect security failed event is the case SM_EVT_LINK_ENCRYPTION_FAILED, but ios have no send disconnect event to keyboard

the issue is easy to repeat, i use the nrf52832 chip,nRF5_SDK_12.3.0_d7731ad,pca10040.h,ble_app_hids_keyboard project s132_nrf52_3.0.0_softdevice.hex

thank you very much!

[run_ar]

I'm afraid I don't have a viewer for the TI sniffer logs. But I recreated this here and I can see that iOS doesn't terminate the connection even though encryption start is rejected. However I'm afraid we cannot change the behavior of iOS, so you will have to add code to your application to disconnect on this event if that is the behavior you want.