Re: Laser Mouse

On Sat, 20 Apr 2024 19:07:42 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

On Tue, 16 Apr 2024 12:06:19 -0700, john larkin <jl@650pot.com> wrote:
>

If you have an Ikea desk and your LED optical mouse doesn't work right
(something about the optics of the varnish) this should fix it:
>
https://www.amazon.com/dp/B08CRZ85DZ
>
It was really annoying to be tweaking a PCB layout and having the
cursor wander around, or get stuck.

>
I think that's called "hunting".  This might help explain what's
happening:
>
"Optical vs Laser Mouse"
<https://www.digitaltrends.com/computing/optical-vs-laser-mouse-explanation/#dt-heading-comparison-optimal-surfaces>
>
"...both methods use the irregularities of a surface to keep track of
the peripheral’s position. But a laser can go deeper into the surface
texture. This provides more information for the CMOS sensor and
processor inside the mouse to juggle and hand over to the parent PC."
>
"This makes laser-based mice better for glass tables and
highly-lacquered surfaces..."
>
"The problem with laser-based mice is that they can be too accurate,
picking up useless information such as the unseen hills and valleys of
a surface. This can be troublesome when moving at slower speeds,
causing on-screen cursor "jitter," or what’s better known as
acceleration."
>
I've done a little tinkering with both types of mice.  I used a
drawing program to draw a 1 pixel wide line.  The optical mouse drew a
fairly "sharp" edged line.  The laser mouse drew a tiny sawtooth
waveform (jitter).  It can be cleaned up with averaging and damping,
but that increased response time, which was deemed highly undesirable
by the gamers in attendance.  It was also possible to see building,
motor, and machinery mechanical vibrations along the line.  That
disappeared for both types of mice when I used a rubber backed mouse
pad or installed rubber "carpet protectors" under the desk legs.
>
No advice.  Just try a few different mice and use whatever works best.

I don't freehand draw lines as such, but I'm sure some people do.
Schematic entry and PCB layout make straight lines that are quantized
to a grid, or move parts and traces on the grid, and the LED mouse on
the Ikea desk made it hard to do that.

I was talking yesterday to Mo about drawing, in a cafe with cool
watercolors of city scenes on the walls. She can draw. She said "you
draw too" and I noted that I only do it with straight lines on a
rectangular grid. Well, rarely, a circle.