How to set the single click speed?

Gene Heskett gheskett at
Fri Jan 22 18:34:51 UTC 2016

On Friday 22 January 2016 11:18:30 Karl Auer wrote:

> On Fri, 2016-01-22 at 16:11 +0100, Liam Proven wrote:
> > Rapid random movements in optical mice is a sign that a hair or
> > other fibre is trapped in the niche where the lens is housed on the
> > underside of the device.
> Yes. Some surfaces don't work well or at all, either, or work with
> some mice and not others (wavelength?).
> But none of those things explain the click issues.
> Standard mice are unbelievably simple critters. They send short
> messages about basic events, and the smarts are in the software. The
> messages are just the current button states, delta X and delta Y - the
> software has to figure out if buttons have gone down, have gone up, or
> are still down (or still up). A "click" doesn't really exist for the
> mouse itself. A click is "button X down" plus "button X up" with no
> more than some configurable time in between, and provided the mouse
> hasn't moved too far between the two button state changes - all of
> which is up to the software to work out.
> The software turns the primitive mouse messages into "events" and
> makes them available to software - so when button X gets pressed and
> released within a certain period, the software will send a button X
> down event, a button X up event and a button X clicked event. A double
> click causes all that twice, plus a double-click event. Most mouse
> APIs include the current mouse position with every event, but the
> mouse itself has no idea where it is - the software tracks the mouse
> position by
> accumulating every movement.
> There is hardware debounce in the mouse, but that's about it. Smart
> mice - programmable gaming mice - can be told to synthesise sequences
> of these message, and some are keyboards as well as mice (because USB)
> or have other not-really-mousey features, but as far as the actual
> mousing about is concerned, it's all very primitive stuff.
> Regards, K.
> [1] When I was writing mouse drivers, the unit of distance for mouse
> movement was the "mickey". In these days of far higher resolution
> mice, the unit may be something else - micromickeys?

Never heard that term before. :)

But what I have done is repair mice, lots of them. I am a CET. 

Usually because they were in short supply in our then amiga based 
production dept at the tv station where I was the Chief, and usually 
only engineer.  But it's fairly common in any device that uses a finger 
lever to depress a teeny microswitch. The problem is often that in the 
automated production, no facility was made in the wave solder machine, 
to hold those switches in solid contact with the PCB as they were 
soldered into, more often than not leaving a 10 to 30 thou air gap 
between the bottom of the switch and the PCB.  So it was up to the 
solder to resist the switching force, and the copper on those boards, 
and its adhesion to the boards was less than needed to immobilize the 
switch, so it first broke the glue joint under the solder pad allowing 
it to wiggle even more, but then copper fatigue set in and the copper 
trace broke.  

The effect was the switch went down, closing the circuit, but the 
connection was broken by the switches movement as the finger pressed on 
down till it hit the stop.  Then of course, when the finger was lifted, 
the copper again made contact and then the switch clicked open, so you 
got a very rapid double click for a while but eventually the copper wore 
away and it no longer registered the click.

You'll often need a very strong glass or a cheap microscope to see those 
cracks in the traces right at the edge of the solder blob on the 
switches leg.  So to fix it, clean off the solder mask for about 1/8" 
down the copper trace, and redo the solder joint including wetting the 
trace with solder while holding the switch solidly in contact with the 
pcb its sitting in.  Not all solders are suitable of course, the smaller 
gauge stuff with 2% silver content seems to have worked the best for me.  

So did educating the user that they did not have to use several pounds of 
force on a mouse button.

Your trivia factoid for the day from a genuine BTDT person.

Cheers, Gene Heskett
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
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