Hi everyone!

I have a bluetooth mouse and since some time I'm experiencing an annoying issue.

When scrolling down (with the wheel) it sends some scroll up signals. I mean, scroll up is 4 and scroll down is 5. When scrolling down multiple times, what I get is something like 5 5 5 5 5 4 4 5 5 5 5 4 5 5 5... And, of course, the opposite when scrolling up. Something like 4 4 4 4 4 5 4 4 4...

It only happens when I scroll quickly, but in the everyday is really annoying, because the screen will do just the opposite to what you want.

OK, so I could just buy a new mouse, but I want to try to correct it programatically.

The easiest solution is to just disable one of the directions, and just use the wheel to scrool down (or up). I have already done that and the results aren't very pleasant.

The best solution, of course, would be to monitor the mouse input and check, through some algorithm if the signal is probably wrong. For example, if I have lots of 5 in a short period of time, and then a 4, so, probably this is another 5. How could I do that?

An easier solution could be always use the wheel in just one direction, and associate the opposite direction with the press of a button. For example, regardless of the direction I move the wheel, it will scroll down. However, if I move the wheel pressing the right button at the same time, it will scroll up.

So, how could I accomplish that? Or you have other good ideas to bypass that issue?

Thanks a lot!

Hi there,

yes, I see. Easily happens with rotation detection, when the rotary speed exceeds the detection speed of the system.

I wouldn't call that a solution.

Exactly as you said: Whenever there's a "scroll up" or "scroll down" event, store it with a timestamp. When there's a scroll event with the opposite direction than the last one before, discard it if less than a minimum amount of time has elapsed. Otherwise, pass it along to the application. The time threshold (probably a few tenths of a second) could be a configurable parameter.

You don't really want that, do you?

[X] Doc CPU

Thank you for the answer, Doc CPU.

But how can I implement that?

I guess I have to intercept the mouse signals before X and then pass to it the correct ones.
I'm just clueless in the implementation.

Hi there,

well, so am I, sorry. But you seemed so well-informed about the signaling from your mouse that I thought you had already tapped the command flow for examination, and it looked like all you needed was a proper algorithm.

[X] Doc CPU

Anybody? =/