Wandering Mouse

I have two Rpi3 machines, one with RISC OS 5.23, the other with Raspbian. Similarly I have two keyboard/mouse possibilities: Logitech K260 wireless, with a single USB wireless dongle, or legacy stuff from an Iyonix consisting of a Genius Netscroll laser mouse and a Chicony keyboard, each with its USB cable. The Logitech setup gives no problem with either machine. However the Genius mouse pointer has odd behaviour with the shut-down dialogue of RISC OS (The computer is now ready to be switched off ), wandering steadily in a horizontal or a vertical direction. It is no great blemish, as in all other respects it seems to work fine. But I am puzzled about what causes the wandering. It is evidently not a fault with RISC OS seeing that the Logitech mouse pointer does not wander. Any suggestions?

It is evidently not a fault with RISC OS

Famous last words!

This issue has been reported a few times in the past (and I think only on the Pi?), but I’ve never been able to reproduce it myself.

However I did buy a new mouse for my Windows PC a few months ago (a rather mundane Microsoft one), so maybe if people keep mentioning this issue I’ll remember to test that mouse with the Pi and see what happens.

This issue has been reported a few times in the past

The Genius Netscroll (model GM-03001A) must be pretty ancient, judging by how worn its finger surface has become. It gives no problems with the shutdown screen of Raspbian. I know nothing about the protocols of how mouse position is communicated by such devices to the USB system; I am guessing that different manufacturers may have interpreted them differently.

I have seen and experienced a wandering cursor on a PC before and the cause? The mouse mat. I understand it was something to do with the mouse laser colour and the colours in the mouse mat. I changed the mouse mat and the cursor stopped wandering.

I also very occasionally get a wandering mouse. I usually use the mouse straight on a lightly-varnished pale wooden desk. The wandering doesn’t occur at all when I use a page I’ve torn out of an obsolete road atlas, so I use that when I’m doing critical work, but it’s a bit of a faff and the wandering is so infrequent anyway that I don’t usually bother.

I have seen and experienced a wandering cursor on a PC before and the cause? The mouse mat.

Using a wireless mouse on a laptop at work (it’s easier to pack and move around comms rooms) I happened to do a small amount of work on the laminate desktop. I paused and after a second or so the mouse pointer wiggled and started wandering diagonally(ish)

I grabbed a sheet of paper and slid it under the mouse -no wiggle,
then removed it – wiggle. Reproducible through 5 repetitions before I moved off to complete the work I started.

So as Gavin says: not a RO fault. Clearly mouse mats need to be matt for optical mice.

No, this has been mentioned before, within the specific context of the shutdown screen, and (I believe) only on the Pi. Definitely not a “fluff on the optical sensor” type problem (and I’d hope that people are smart enough to check for such an issue before trying to report it as a bug here)

https://www.riscosopen.org/forum/forums/9/topics/3761?page=1#posts-48118

I think it’s been mentioned more than just that one time, but searching for posts about it in Google is a complete pain due to each message being repeated about 10 times (I was even going through so many pages of results that the site decided to throw a captcha at me to prove I wasn’t a bot)

ADFFS has been known to trigger “wandering mouse syndrome” on Pi’s. I believe the cause was power droop causing the USB wireless dongle to not receive enough power and then report phantom mouse movement.

I’ve noticed that tight loops and high numbers of CPU mode switches/sec can cause CPU power spikes, which in turn cause the power droop issue.

Possibly not the case here, but worth ruling out.

I get this fault too. Started maybe a couple of months ago. Mostly on the shutdown screen but occasionally during normal use too. The pointer just seems to continue on in one of the four directions at a constant rate depending somehow on the direction the mouse was last moved. Never diagonally.

I too have experienced the wandering mouse at the shutdown screen, yesterday. I did try to replicate my actions, prior to shutdown but no joy there!

Observation: Following a shutdown, the pointer started to move left along the Y axis, if I moved the mouse briefly in the other direction along the Y axis, the pointer moved to the right along that axis. I did try the X axis and the same thing happened. No diagonal movements, just either a gradual up or down, left or right.

Rebooted and issue gone.

I experience a slightly different behaviour. Under heavy load from LanManFS/ShareFS and/or my USB disk, the pointer sometimes jumps in the upper and slightly to the left direction. I suspect it could be due to related to USB power usage.