SLAM and lidar exploration

Slamtec RPLidar visualization

In this part I wanted to play with mechanical 2D lidar from Slamtec - show basic scan data in a plot without third-party software (except for QT and SDK) with something like that:

This comes with three workflows:

• Visualize real-time data in a polar plot
• Saving one scan into proto text format
• Visualizing previously saved data into a plot

Setup

For visualization set up my other project and launch it in a separate terminal.

Install SDK .\install_rpildiar.sh. More details on this later

Configure USB. Check ls /dev/ttyUSB* to see the available port. You need a chmod permission or probably dialout.

Visualization

If visualizer is running in a separate terminal, this shows real-time data from lidar

blaze run //:runner_main -- --usb_port=/dev/ttyUSB0 --visualizer_port=9000

if one scan was previously saved, launch this to show it

 blaze run //:runner_main -- in_path=testdata/lidar.txtpb --visualizer_port=9000

Saving one scan data

Run this or use file in testdata:

blaze run //:runner_main -- --usb_port=/dev/ttyUSB0 --out_path=/tmp/lidar.txtpb

More info

Slamtec SDK has the latest release in 2019 and the main branch was completely out of sync issue. To get things moving I forked their SDK with fresh release url of 2025.

The SDK has an ancient makefile. Bazel has a make rule in rules_foreign_cc but I could not make it working - issue. In order to work around I made a shell script that produces headers and static libraries in third_party.

As I mentioned I did not want for QT to usurp my project, I just wanted to have a quick fire-and-forget visualization in a simple polar chars.