We are writing you on behalf of PIC4SeR, a University Research Centre located in Turin, regarding some issues we are having with your products, in particular with both the Turtlebot3 Waffle bought.
The problem concerns the Intel Realsense camera, which works differently according to the following cases:
1) if we use a remote PC:
-if the LDS Lidar is plugged or NOT the camera DOES NOT WORK and the Waffle loses its connection.
2) if we use the Turtlebot3 as master and slave:
-if the LDS Lidar is plugged the camera DOES NOT WORK and the Waffle loses its connection.
-if the LDS Lidar is NOT plugged the camera USUALLY WORKS.
3) if we plug directly the camera to the Intel Joule board it WORKS
This last case falls outside our project purposes.
We have therefore discovered that it was a current supply problem related to the USB HUB, which is not able to fulfil at the same time the two device requirements.
Once replaced with a better HUB, the Turtlebot3 is able to work concurrently with both the devices, but when using RViz the images are not displayed in almost real-time, but with around 5 seconds delay.
Have you already encountered these complaints from other customers?
Can you suggest any advice related to our problem?
Is there anything that we could do to improve its bahaviour?
We would be most grateful if you could look into this matter as soon as possible.
When connecting multiple USB devices that consumes significant power, it is recommended to use external powered USB hub.
There could be several reasons for having delay with the image, so it is difficult to say the exact cause.
The followings are suggestions for the image delay issue.
- If possible, process the image from the Remote PC. TurtleBot3 has limited processing power.
- Make sure that the bandwidth of Wi-Fi router is enough for image streaming.
- Try using smaller image size or lower the FPS rate.
I suggest to post the issue on GitHub TurtleBot3 issue page as TB3 developers are maintaining the page so you'll get faster response.
Also it helps other users who have similar issue can share the experience and find the solution together.