CC2640: bonding, reconnection, Galaxy Note10

Kichang Yi

Part Number: CC2640

I use cc2640f128 with my custom board, sdk 2.2.2.

I have reconnection fail issues of "Galaxy Note 10" after bonding. (Paring method : Numeric Comparison)

By the way, this issue is occurred when the Note10 is second device boded to the cc2640.

When the Note10 is first phone after firmware image is downloaded to CC2640, there is no problem.

But after another Note10 or S10 5G is bonded first, the issue is occurred.

I guess the chipset of Note10, S10 5G have some bugs about BLE Bonding Logic.

And I also guess the BLE public mac addresses of the chipsets are same.

So when re-connecting, cc2640 maybe misunderstand that 1st data of bonding list is the information of the device.

I wonder that my guess is right and there is some work-around solution or not.

I captured packets when re-connection fail as below.

Thanks all.

0 J Lindh over 6 years ago

Hi,

Assigning an expert to comment.

0 Marie H over 6 years ago

Hi Kichang,

I don't see any failure in the sniffer log you posted; the two devices connect and use the bonding information to encrypt the link.

0 Kichang Yi over 6 years ago in reply to Marie H

Hi Marie H,

Yes, that is correct. GAP Layer connection is good.

Then when both devices try to connect to GATT, the problem is occured.

After "Start Encryption Req.", "RETRY" and "Unexp. NESN" are displayed repeatedly as upper captured log.

In this respect, I think that each encryption key value is different.

0 Marie H over 6 years ago in reply to Kichang Yi

Hi Kichang,

I think this is just the sniffer that missed a packet and is not following correctly.

If one of the devices tries to use the wrong key the other device will disconnect immediately according to the Bluetooth core spec.

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