Of what does a notification package consist? ( Packet Structure )

[muhkuhns]

I mean what kind of header information and stuff besides the data. I could only find this for advertising packets.

A graphic or list like this would be nice:

byte 0-1 // byte 2-30 // byte 31

sendername // data // crc

and a citable source :)

[endnode]

Well citable source is easy: BT SIG specification 4.0 or higher;) If you mean "Handle Value Notification ATT method" it is standard PDU, isn't it? I'll leave these few drawings here but I believe you'd like to to get access to this presentation: original presentation by BT SIG from 2010 during official introduction of LE as part of BT 4.0 (member login required but registration is for free).

Cheers Jan

PDU on LE LL layer

PDU on LE ATT layer (no authentication)

PDU on LE ATT layer (authentication signature)

Note:

"Opcode" for "Handle Value Notification" ATT method is 0x1B. "Attribute Parameters" consists of 16-bit ATT handle number and actual data.

[LJohn]

I was told that when using UART the payload is maximum 20 bytes per transmission. According to this graphic (m.eet.com/.../bluefig2.gif) it appears that the payload is up to 37 bytes large. If i substract the 6 bytes for payload length, L2CAP Length, 0x0004 (ATT) and Attribute Opcode I would expect to be left with roughly 31 bytes. Where do the missing 11 bytes per transmission in the UART app go?