bonding lost in Android after Error Code: Attribute Not Found (0x0a)

[hossein_m]

Hi,

I have an NRF52840 as the peripheral and an Android phone as the central. Most of the time the connection can be established without any problems but sometimes during the connection, the information about the bonding gets lost from the pairing list of the phone.

After many trials I succeeded to reproduce the issue with the sniffer it seems that the phone is sending many Attribute Not Found (0x0a) errors and they lead to initiating the pairing from the beginning.

Can you please tell me what this error means? and how it can cause bonding deletion.

[Susheel Nuguru]

ATT NOT found is not necessarily an error while discovering services. The central normally tries to send a querry until it gets ATT_NOT_FOUND_ERROR. Explained well in the Message sequence charts here

[hossein_m]

I did a lot of tests and finally regenerated this issue again. The connection works fine most of the time, but in some rare cases, it stops connecting. When this happens after a few attempts to reconnect Android deletes the bonding information and tries to reinitiate the pairing which leads to the sniffer logs in my first message, but in iOS the pairing is still on the list, so unless you delete it yourself you cannot connect anymore.
It seems that the bonding information is somehow deleted from the nRF flash memory but I cannot understand why.
Have you ever seen anything like that? What do you think I should do to figure this problem out?