"Red is Dead" Optical Mice LED Change

A reader sent us the HOWTO for changing that red LED on your fancy-pants new optical mouse to blue - or, I suppose any other color. I think I'm fine with what I've got - although, the glass tops on tables does make using optical mice a pain there.

why??

[Anonymous Coward]

You don't really stare at the light under your mouse do you?

woodgrain

[Anonymous Coward]

it doesnt like wood grain either.

-pubarso

Major Headline!

[rjstanford]

Next on Slashdot, a complete HOWTO on adding those leftover red LEDs to your car's window washer nozzles.

I mean, really. I know that we've been getting sillier lately, but this? Not exactly News for Nerds. Stuff that matters. Is it?

In unrelated news, a Japanese study [com.com] shows another link between computer use and health problems. But hey, that sort of thing just isn't as k3wl....

What about the detector?

[P-Nuts]

I'd be worried that the detector might only be sensitive to longer, redder wavelengths. It would probably be worth checking on what component the mice use, and what its specifications are.

Neat mod...

[vasqzr]

I'm guessing red LED's are used in the first place because of the cost. I read somewhere that red LED's are pennies and blue LED's are like $2.00 USD each. I probably read that on the Internet so take it with a grain of salt.

I'm wondering how many more blue LED's we can take. I remember the first thing I seen with them was the Sony PlayStation 2. If you go in to Circuit City or Best Buy, it seems like EVERY stereo, DVD player, TV, laptop, etc has blue LED's! I'm sure consumers like them, but I can see this fad passing soon.

If anyone opens up an old optical mouse, the kind where you need a special mouse pad, make sure you don't remove the infared LED and replace it with a blue one :-)

The reason they use red...

[GoRK]

Yes, red LED's are cheaper, but there is another reason, too.. They also want to use the cheapest CCD available. That's going to be a monochrome CCD that's sensitive to larger wavelengths. A red LED is going to work better on that.

With that in mind, an Infrared LED would probably work great with optical mice and their cheap CCD's.. maybe even better than red. You might have to remove an IR filter from in front of the CCD, and be wary of using them in a room with flourescent lighting, but it'd be good to try. How cool is an optical mouse with apparently NO light?!?!

If you want the "cool" blue look for whatever twisted ass reason, just use a blue LED and an IR LED in paralell. You might have to play with different led's/led voltages to get the right balance between a responsive mouse and the cool blue glow your riceboy heart desires, but again, it should work.

~GoRK

Re:why??

[GT_Alias]

Cuz d00d....it's 1337!!

Serously, why do you need to ask why? Present a geek with a gadget, and he will find some pointless way to modify it, just for the sake of modifying it.

Me? I think it'd be cool as hell to have a blue LED light under my mouse.

Re:why??

[Jugalator]

Still, MSI color their mother boards [msicomputer.com], including ports, etc in a purple hue. I'm pretty sure they'd get the material in that boring green color easier, but it's all about standing out of the crowd. Same reason to why you'd make your LED blue.

Re:Major Headline!

[kaden]

Perhaps because that study is bad science? It ignores the fact that people with the emotional/physical problems they describe are more likely to be internet addicts than the average person. They have proven no strong, general correlation, and it is akin to saying "Piloting a 747 makes you a very smart and focused person" when really, the people who are doing that usually already have those qualities.

Re:Red is Dead

[JUSTONEMORELATTE]

I fear you think too highly of this generation's memory
Never attribute to cultural literacy that which can adequately be attributed to a simple rhyme.
--

-1 Moron...

[Andy Dodd]

Um, IR is the best thing you can use.

All IR LEDs (except for maybe some outlandish ones, but none that I know of) are near-IR. Si isn't transparent to near-IR, it's transparent to far-IR (i.e. the type of IR given off by not-obscenely-hot objects). In fact, as others pointed out, most CCDs and CMOS sensors have their sensitivity peak in the near-IR area! (Note: This is the main principle that enables Sony NightShot mode. In most camcorders and digital cameras, there is an optical element that filters out near-IR light because it will utterly kill proper color rendition - In NightShot mode, this filter is moved out of the way, allowing more light in, which happens to be at the sensor's peak. Color rendition goes down the tubes, but recording something is better than recording nothing.)

Re:woodgrain

[Archfeld]

it is not the wood grain but the sealant that is most likely causing the problem. If the laser reflects, things go awry. A piece of graph paper works wonders. The double LED mice also reduce the skipping noticeably.

Re:Resolution

[Anonymous Custard]

Let's see... 700nm would have to equal one pixel movement, right? That means that for a full 1280-pixel travel across the screen, he'd only have to move the mouse 0.896mm (I think).

(Disclaimer: fuzzy math ahead)

Who says the mouse hardware has to send a constant (not variable) motion:pixel signal? Lets assume it sends a 'move cursor' command once per millisecond. I (just now!) moved my mouse across my 1024 pixel screen, and it took about two inches (5 centimeters) of mouse movement, at default windows mouse settings. That's about [google.com] 2.054 pixels per millimeter mouse movement. During each millisecond, a move of anywhere from 700nm-1cm could translate to a one pixel cursor movement, then 1.00000001cm - 2cm would be two pixels, etc. The sharpness would only come into play if someone managed to move it 701nm in less than one millisecond, it would still correspond to a one pixel movement, where as less accurate mice would not move the mouse at all.

I don't think it matters whether your beam is 400nm or 700nm, unless it helps the laser track the mouse across non-optimal surfaces such as solid colors or glass. What may appear solid to a sensor at 700nm resolution could appear slightly patterned at 400nm, kind of like doubling magnification on a microscope allows you to find texture on surfaces which previously seemed flat.

Minor nitpick

[vasqzr]

This isn't a HOWTO. Read the HOWTO-HOWTO.

It's more like a tutorial or informative web page.

Please don't mod me down!

Re:Logitech did them

[NortWind]

Get Logitech DUAL sensor optical, especially for gaming where you need to mix fast acurate moves with precision moves.

Phototransistors like RED

[bigberk]

OK, true, these modern optical mice don't use simple phototransistors but my guess is that they use devices based on semiconductors that behave like phototransistors.

Silicon phototransistors are most sensitive to near-infrared light. The closest visible frequency to this is red, which may explain why you see red LEDs a lot in photosensitive equipment.

That in mind, you may "see" (ha ha) good results using an infrared LED.