Notifications
Clear all

Getting an rpLidar A1 from AliExpress to work

5 Posts
3 Users
3 Likes
759 Views
(@alextheprogrammer)
Member
Joined: 1 year ago
Posts: 12
Topic starter  

Hey, I just got my RpLidar delivered from AliExpress ( https://www.aliexpress.us/item/2251832709015672.html?spm=a2g0o.order_list.order_list_main.4.2e6b18029Nhc2e&gatewayAdapt=glo2usa&_randl_shipto=US) and my first thing was to test it to make sure that it works. 

 

One weird thing that I noticed right away when comparing the pictures from their page to what I got in the box is that the bottom plat is missing. Left picture is what it should look like, the right one is my device: 

image
image

 

Then they had a manual card included pointing to some default software - RoboStudio for Windows. I installed it but to my surprise there's nothing there about the lidars. Googling around I found that there should be LiDars menu at the top toolbar but I don't have it.

image

 After installing the driver that I managed to find on their website, the lidar appears on the list of devices with the name suggested on those forums:

image

 It's also spinning but their software still doesn't show the lidar menus or otherwise allows me to interact with it in any way... Well, I decided to test it with ROS instead (as it'll be used on the robot via ROS and ROS navigation packages much like in James Bruton's "Really useful robot"). So on my VM with Ubuntu and ROS I installed their package into the catkin workspace, recompiled it with `catkin_make`, launched the roscore and the their package but it crashed with `buffer overflow` from the geometry2 dependency package.

image

 On this forum I found that there was some issue with one of the dependencies geometry2 and that in a newer version they fixed it: https://answers.ros.org/question/361551/amcl-buffer-overflow-detected/?answer=410121#post-id-410121

I tried updating all packages of my ubuntu including those of ROS, purging all ROS Noetic packages and reinstalling ROS noetic, even manually cloning that geometry2 into my catkin workspace and trying all release tags to see if any of the versions fixes the issue - nothing helped, the error is still there. I even had to add a reply to that forum but it's still waiting moderation. 

In a meanwhile I have no clue how to make sure that my RpLidar works at all. Just in case, coz of the missing bottom plate, I opened a case with AliExpress but the seller wants me to "close the case and they'd help" that doesn't sound too trustworthy. I can try to ask them how to test to without closing the case but I'm not sure if they, a small shop, would be able to tell me anything.

image

Open for your advice. 

This topic was modified 1 year ago by AlexTheProgrammer

   
Quote
(@davee)
Member
Joined: 3 years ago
Posts: 1641
 

Hi AlexTheProgrammer,

  Sorry, I have no direct experience ... maybe someone else can give more specific aid ... I am just looking at the seller's website you referenced and your note.

  To be fair to the seller, they appear to show the two versions of the device, with notes about one being the old model and the other the new one.They say in their notes:

In December 2020, the RPLIDAR A1 lidar was upgraded from A1M8-R5 version to A1M8-R6 version. As there is still a small amount of A1M8-R5 in stock, the specific version is subject to the buyer receiving the goods.
The main changes are as follows:
1. The white lines turn black
2. The black adapter plate turns green
3. A black bottom plate was removed from the back of the lidar

As is all too usual for entries on AliExpress, it is all a bit confusing, but have they actually sent you at least one version of what they were offering?

------------------

I note they also claim, that it is possible to do a 'plug and play'

image

-----

I can easily understand your concerns of closing the case before getting some sort of resolution.

Maybe offer to close the case, AFTER they have provided enough information for you to see this 'plug and play' example working ... if it is so simple, that should only take a few minutes. Once you have the information, and you can promptly close the case. That way, you can both be reasonably happy??

--------

Just a thought ... I am not a diplomat or negotiator... and I have no connection (excepting as a very small scale customer) with AliExpress or any company or person in that continent.

Good luck, Dave


   
ReplyQuote
(@alextheprogrammer)
Member
Joined: 1 year ago
Posts: 12
Topic starter  

Update: 

 

After googling for a particular error and then using google translate to translate one of Chinese pages of the forum that had an error code that I encountered, I found a link to this page of their test software releases: https://github.com/Slamtec/rplidar_sdk/releases and with frame_grabber I managed to retrieve an image from the lidar. 

When I put in a cardboard box, the outline of the box appeared:

lidar in box

 when it was just sitting in my desk, here is the image:

lidar on my desk

 
So I guess, the lidar itself works, it's just ROS integration that doesn't. I probably should close the AliExpress dispute then. 


   
DaveE reacted
ReplyQuote
Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 3 years ago
Posts: 6856
 

@alextheprogrammer Before you do, see if you can get more/better information/sample code from the vendor first. Just in case.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
Sure you can learn to be a programmer, it will take the same amount of time for me to learn to be a Doctor.


   
ReplyQuote
(@davee)
Member
Joined: 3 years ago
Posts: 1641
 

Hi @alextheprogrammer ,

 Good to hear you have at least some success .. hope you can make it work properly in the near future.

  I tried to give your post a like .. but the forum seems a bit lethargic at the moment .. I sympathise with it!

    Late edit .. Just seen it has changed now.. I guess it was on its tea break.

Best wishes, Dave


   
ReplyQuote