Communication Protocol

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Copyright (c) 2009-2013 RoboPeak Team
Copyright (c) 2013-2019 Shanghai Slamtec Co., Ltd.
Format of the data response packets (Extended Version)：
RPLIDAR may also respond in following response packet format according to
amount of measurements and the link bandwidth. The actual data packet format
could also be fetched via GET_LIDAR_CONF command.
Figure 4-15 Format of a RPLIDAR Express Scan Data Response Packet
(Extended Version)
RPLIDAR sends above packets cyclically if it’s working at very high performance
mode, but transmitting via a limited bandwidth serial port (such as 16000sps at
256000 bps for A3). There are 32 sub structures called ultra cabins included in each
packet. Ultra cabin uses 4 bytes to store 3 measurements. As a result, each ultra
capsuled packet contains 96 measurements.
Definition of each field is defined as below:
ChkSum[7:4]
sync1
ChkSum[3:0]
8
3 0
start_angle_q6[7:0]
8
0
start_angle_q6[14:8]
8
0
ultra_cabin[0]
32 0
+0
+1
+2
+3
+4
Byte
Offset:
sync2
8
3 0
S
7
ultra_cabin [1]
32
0
+8
ultra_cabin [31]
32
0
+128
…
12 0
+0
major
Ultra Cabin
predict1 predict2
22 32