> For the complete documentation index, see [llms.txt](https://campus-rover.gitbook.io/lab-notebook/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://campus-rover.gitbook.io/lab-notebook/fiiva/laserscan-definition-modify.md).

# laserscan-definition-modify.md

### by Harry Zhu (courtesy of TA Adam Ring)

This guide showcases how you can modify the definitions (e.g. range\_min) of the LaserScan message published to the /scan topic. It is also a brief “guide” on how to access and modify files on a Turtlebot.

Turtlebot’s LaserScan message is specified by the ld08\_driver.cpp file from this repo: <https://github.com/ROBOTIS-GIT/ld08\\_driver/tree/develop/src>. You can modify this file on your Turtlebot through a terminal on vnc.

## Step 1: ssh into your robot, do not do bringup

## Step 2: cd to the right directory

`cd catkin_ws/src/ld08_driver/src`

## Step 3: enter nano editor

`nano ld08_driver.cpp`

## Step 4: go to line 63 and fine

`scan.range_min = 0.0;`

## Step 5: modify the value as you see fit

## Step 6: save and exit

ctrl + S to save, ctrl + X to exit the editor

## Step 7: remember to cm

`cm`


---

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