SWRU068
10
The ID is intended to be used for unique identification of different modules. However,
this is not exploited in this software revision. All modules are addressed using the public
address (0x00).
The TYPE is used to separate between an original message (0x80) and an acknowledge
(0x81).
The 3 DATA bytes are used to code the blinking sequence. Every bit represents a 0.1
seconds period approximately.
No end of packet is implemented.
The data packet is shown in the figure below.
The figure below shows the symbol coding and an example of a packet with the pre-
amble and SOF timing.
3.4
Data transmission protocol
The data transmission protocol is very simple, using only packet acknowledgement.
When a data package is received without errors, the packet type is checked. If it is an
original message, it is shown on the LED, and an acknowledgement is sent as a reply.
Preamble for >1 second
SOF
Data field:
ID, TYPE, DATA1,2,3
Preamble (synch symbol):
SOF, start of frame:
Data symbols (Manchester code):
1=
0=
Preamble
SOF ID TYPE DATA1 DATA2 DATA3
