Good morning!
We’ve been testing some things on Magni, but suddenly, a problem dawned on us we have no clue of what’s going on. Magni starts moving in place by itself, slightly left and right, like it’s shivering or trying to correct itself on an unknown trajectory.
The weirdest part is that, at first, we thought that was a problem with some command that the Rasp was sending to the Magni, but when we turn off the Raspberry, the problem keeps happening - it keeps turning left and right on its own, even with the Rasp turned off. We’ve noticed that it only begins to happen when we send some command through cmd_vel in the Rasp, but we don’t know how to stop it, or what’s really causing it.
Does anybody have any clues?
Thanks in advance!
Here, we’ve made some youtube videos to show the robot moving on its own and the corresponding odometry showing that!
Well that’s interesting, I was going to say that it may be related to the motor node PID parameters, but if it happens when the Pi is off that can probably be dismissed.
Which version of MCB firmware are you currently running? Perhaps try loading a few of the newer ones in case it helps: https://learn.ubiquityrobotics.com/firmware-upgrade
@mjstn2011 may know more if it really is MCB related.
Hello, Good afternoon!
My name is Lucas and I’m from the same team as Felipe who asked the question.
I appreciate the answer.
The firmware version of MCB is 31 with hardware revision 5.0.
Is there a problem or a limitation for me to with upgrade the firmware? Can it hinder the functioning of the hardware? Can any hardware revision have the latest firmware version?
Thank you very much for your attention, I await answers!
Thank you for the reply. Firmware version 31 is not an officially approved release and could explain your issue on it’s own. I do not know how you got it on a robot but perhaps in a replacement board it was never upgraded and sorry if that is the case.
Please see these pages where the current ‘default’ is v35 and although we have much more current firmware v35 will not do as you describe if batteries are properly charged.
https://learn.ubiquityrobotics.com/firmware-upgrade
Current boards have the MCB board revision in bright white text on the left edge of the board. Older boards also had the revision there but it was often hard to read so we offer this page (also on our ‘learn’ pages that may be of assistance:
https://learn.ubiquityrobotics.com/PC_Board_RevId
Lastly, v35 will work well on MCB rev 5.0 although you cannot run a Pi4 on any MCB with revision less than Rev5.2 (I realize that is not your question but simply be aware that Pi4 did not exist when boards prior to Mcb 5.2 were made and sadly we are not clairvoyant enough to outguess the next Pi revision at the time. 
Hey, thanks for the reply. We updated the firmware version using your tutorial to version 35 and the problem of moving on its own has stopped, but the robot continues to make noise on the wheels, as if trying to move.
Another thing, our MCB review is 5.0 and we are using the raspberry pi 4 without any problems. What is the problem with using it that you mentioned above?
We have two robots here with ubiquity board rev 5.0 and firmware 31. We have updated both boards to firmware version 35 and both have noise behavior on the wheels.
The excessive noise issue has been mostly addressed in v40 which is at this time a ‘beta’ version.
We have v40 beta on our repository here: (in the firmware folder)
The command line way to upgrade firmware is documented here: Upgrading Motor Controller Firmware - Magni Documentation
This is a beta so we would appreciate any odd behavior you see but we have been using it for a few weeks now and it looks very promising.
You should not run a Pi4 on a rev 5 board because of the way the 3.3V supply is derived.
We have found differences in the ability of Pi4 to work and in fact in at least a few cases things on the Pi4 start to fail relating to network. This has been designed out as of rev 5.2 so that and later boards are the only ones we can stand behind.
I want to stress that we are at the mercy of new boards that come out and with some things such as GPIO lines and Sonar we have been able to fix things in our image for Pi4 but this is a hardware power supply issue not forseen in earlier revs.
If it works for a lab unit or something you may be ‘lucky’ but do NOT SHIP A PRODUCT WITH A PI4 ON ANY MCB PRIOR TO REV 5.2
Thanks,
Mark
