I am sending 660Bytes per 200ms from CC2540 keyfob using a 10ms connection interval and 20 user data bytes sent in GATT notifications. 4 notifications are sent every 7ms, based on an OSAL timer. When sending the notifications, a check is made to see if a buffer is available.
When I monitor the HCI ATT_HandleValueNotification events come out from CC2540 USB Dongle, I found the subsequence of the received notifications is different form the sending sometime. Something like:
P=2, pS=25, Sn=26 P=2, pS=26, Sn=25 P=4, pS=13, Sn=15 P=4, pS=15, Sn=13 P=5, pS=19, Sn=20 P=5, pS=20, Sn=21 P=5, pS=21, Sn=19
P is the SN of 660 bytes packet, pS is the SN of receiving and Sn is the SN of sending.
And you can see the problem occurs randomly.
Does anyone have the same problem? How can I fix this?
This problem has been noted before by others, but as far as I am aware TI has not provided a concrete answer on why this occurs and if there is a fix in the next SDK.
For now you may have to use a sequence number and re-order the notifications yourself.
Look forward to a TI update on this one...
Yes, I found the same problem bellow:
Waiting TI to update...Thanks a lot!
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