Ethernet connection between Magni's Pi and NUC drops radomly

Hi all,

I have a internet switch setup to my Magni’s raspberry pi ( which without the switch i’m facing something like 15+++% packet loss ), with an NUC, and other sensors, all through ethernet connection to the switch.

The issue that I am facing is that the ethernet connection to the raspberry pi will drop all of a sudden (could be running for minutes, hours, etc., then drops). This situation would be unrecoverable except if I plug out the ethernet cable and plug it back in, and then everything runs fine until it happens again.

Scrolling through the forums I find this that fits what I am facing, but without a viable solution:

It seems like the cause is an inadequate power supply ( not being rated for 3A ). Does anyone know if the Magni is supplying 3A? Is there a way to resolve this issue?

Please tell us the Pi type you are using (Pi 3 or Pi4 with 4GB?).
Also tell us the MCB board revision that is in bright white silkscreen on the left edge of the board as you look at the Magni.
If you know the image you are using please tell us that as well.

In general the supply is rated for 8A, however there are other issues with voltage levels that may cause these issues at this point. @mjstn2011 has been looking into it for some time, but right now the most reliable way is to get a USB-Ethernet adapter to be sure.

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This post has reminded me of the importance of this topic so today we have bumped up the priority of this issue and will be looking back at this issue again. It has been on hold for some time due to other priorities. Thank you for your posting @jh_c we need reminders from time to time.

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It is a pi4b with 1gb RAM, the MCB board im using is Rev 5.3. Sorry, im not sure how to check what image that I am using/

Hi, thanks for the suggestion! I will try that out. Can I ask if it is possible to go into more detail into what causes the ethernet drop?

We only have theories as to what causes the ethernet to drop out. We have been unable to find a repeatable condition with a specific Pi4 board to allow us to confirm any theory yet. We suspect some Raspberry Pi 4 boards are more likely to have this issue than others but again, we don’t have boards that can do this with any repeatable setup.
Our top theory is it has to do with the Pi4 changed the power supply requirement to be a 5.1 volt supply and our board was designed for 5.0 V to the Pi 3. We are actively going after determination of the true cause of this problem. We do know that it tends to show up in wired ethernet and that the WiFi connection is seldom if ever impacted.

As a short term workaround perhaps you can connect to the Pi4 using it’s onboard WiFi hotspot or tell the Pi4 to connect to your house WiFi using our ‘pifi’ tool.

The middle of this page discusses the hotspot: Connecting a Workstation, Starting And Stopping the Robot | Learn Ubiquity Robots and ROS

This page shows how to connect to your own wifi: Connecting the Robot to Your Network | Learn Ubiquity Robots and ROS

@mjstn2011 thanks again for the response and fixes! Thanks for the suggestion to use the onboard wifi, but we wanted a more stable connection. We are running the Magni as a mobile base with a NUC stacked on top as the ros2 ‘brain’. The workaround suggested by @MoffKalast seems to be working nicely so far (~6hours run time w/o dropping)!

There have also been reports that the Pi4 ethernet can be more picky about the router in use and some people have swapped out a router (or switch) to solve network issues. Again, I don’t have first hand proof, have only seen this being reported so who knows how valid it may be.