have just purchased an incredibly cheap USB optical mouse off eBay...it's one of those transparent affairs that lights up blue.... thing is the main LED that triggers the optical receiver is red....as I said it's a bit fancy and the red LED flashes and pulses when idle. I'd like to know if it is possible to change this for a blue one....every optical mouse I've ever seen has had a red LED apart from high end gaming units...can anyone tell me if this is possible?
The optical imaging sensor (read: tiny digital camera) are attuned to red spectrum. If you replace the red LED with blue one, your mouse may not track well if at all. This is what even $100 mouse with fancy blue lights still uses red light for tracking.
It is possible to get away with color change if you used a white LED. Put blue filter around its side so it'd appear blue unless you picked the mouse up. And a red filter on the bottom for red light. This
*may* work but no guarrantee.
When you hear the toilet flush, and hear the words "uh oh", it's already
too late. - by anonymous Mother in Austin, TX
Correct. But... That does *NOT* mean that it's completely insensitive to other colours and it *certainly* doesn't mean that anything-other-than-red will make the sensor go haywire!
The keyword here is: brightness
"high frame rate" + "high contrast requirements" = "bright light required" A 3.5cd red LED is relatively cheap *and* meets that requirement, while still meeting eye safety standards. (And that's why the sensor's optimised for 639nm)
That is, if you purchase you blue LED at 'case modding' or 'spare parts' outlets. Those critters barely make it past the 'health and safety' luminous intensity of 3cd. And that's nowhere near enough to compensate for the (35-40%) reduced sensitivity for 'blue' light!
Go find a 8cd (=8000mcd) blue LED (so you don't have to worry about the extra voltage drop that blue LEDs have (saves you from re-adjusting the LED current)) and please bear in mind that from then on, your mouse will fall under the same hazard category as lasers pointers (ie, don't let children play with it!)
#ifdef FLAME That's some really crazy idea, a clear indication that you don't 'get it' and it will certainly not work. (Unless you use a 25cd white LED to compensate for this madness). (And you still have some red light leaking, keeping the OP's eyesore intact). #endif
At green, the sensitivity will be reduced by merely 15%. With
5.6cd-bright green LEDs being commonplace (equivalent to a 4.7cd red LED from a mouse sensor's perspective), I've no trouble believing that it /does/ outperform the original 3.5cd red one.
(And I'm happily mousing along with a 8.5cd white LED on board. Still tracks true on black cloth!)