Slamtec RPLIDAR A1 - Page 20

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Copyright (c) 2009-2013 RoboPeak Team
Copyright (c) 2013-2017 Shanghai Slamtec Co., Ltd.
The descriptions of every field within the above packet are listed in the following
table:
Figure 4-12 Field Definition of RPLIDAR Express Scan Data Response Packet
Field Name
Description
Examples/Notes
sync1
Data packet start sync flag1.
Always be 0xA
It is used by host system for
identifying the start of a new
response packet.
sync2
Data packet start sync flag2.
Always be 0x5
It is used by host system for
identifying the start of a new
response packet.
start_angle_q6
The reference value for the angle
data in the current response
packet.
Stored with fix point number in q6
format and the unit is degree.
Range [0-360）
Please refer to the following
sections for information about the
calculated method of the angle
value.
It adopts the same coordinate
system definition with standard
SCAN request.
Actual angle
=start_angle_q6/64.0 Deg
S
Start flag bit of a new scan
When S is set to 1, the current and
incoming packets belong to a new
360
o
scan.
ChkSum
Obtained by calculating the
response data packet using XOR
operation to each packet data byte
and accumulating them together.
It is used for checking the validity of
s response data packet.
cabin
a 5-byte data body with the angle
and distance value of two
measurement sampling data sets.
A data response packet contains
16 group of cabin data.
Please refer to the following table
for detailed definition.