View Full Version : wanted for science experiment,

04-20-2006, 05:10 PM
anyone have a sick optical (neutered type) mouse to spare?

bad cable ? bad switches?

only one axis working? (although that's more likely to happen with an encoder-wheel mouse).

This experiment doesn't (yet) justify sacrificing a new one. I may also check the church thrift stores locally...



04-20-2006, 05:14 PM
For about twice the cost of shipping, you can buy a non-name optical mouse brand new. Last I checked, the "miniature" mice were running about $10.

04-20-2006, 06:01 PM
Never mind.

I just orderd three for 11.85 total with free shipping.

I can wantonly sacrifice them now.

04-21-2006, 02:09 AM
Cool, now tell us about the project, or die!

04-21-2006, 02:23 PM
Or both?

Does it matter in which order?

1) Environmentally blind them by removing their red floodlight (they'll need their eyes - I don't want them REALLY blind).

2) Cut off their tails with a carving kniife (have to do that myself - I'm not a farmer, so my wife isn't a farmer's wife, and she's not interested in the project anyway.)

3) Transplant IR led's. Some research is needed regarding focus vs wavelength. (Defocus will affect the OTF/MTF of their eyes and degrade contrast detection.) This has been done (Spode's Ode; Aidan II poster) for mouse purposes.

4) Increase led current if necessary to boost mousie's photopic curve to IR.

5) Baffle the IR floodlight, perhaps with a pinhole, or at least a smaller aperture.

6) Implant microcontroller to scale mouse-speak to film format fo choice.

7) Phase I - mount on back of a rollfilm camera as film counter.

8) Phase II; hack pcb down or lay out a new one to allow mounting inside homebrew cameras.

05-08-2006, 10:03 AM
OK Steps 1 and 3 are done. Step 4 not apparently necessary. Still need tail for testing.

TV remote IR LED installed; I'm thinking/hoping that without altering other spacing, the longer IR f.l. will require/allow a longer distance between surface and mouse 'eye'

Folder some paper to make spacers to test mouse vision on stilts.

4 sheets paper crudely folded, roughly 0.018"/0.45 mm still working. This allows space between mouse and film path, like thru a camera back (or inside).

06-30-2006, 03:17 AM
I can't imagine, which kind of images do you want to get?

06-30-2006, 11:01 AM
Hmmm, interesting. Does the ink on the backing paper really have a different IR reflectance? What will this do to color film?

06-30-2006, 11:34 AM
My interest was in using the mouse as a dsiplacement sensor (film distance counter).

There IS a website where someone wrote a program to read the pixel contents of an Agilent mouse.

Both the Agilent and competetive mice have test modes and internal functions not discussed in the data sheets (when those are available...OK for Agilent, hit-or-miss for others). No response to my inquiries from mfrs. I would like a way to tell how well focussed the IR is. For now I just verify mouse function.

First place I may try this is on a camera with homemade rolls of ortho (extra spectral safety buffer).

I didn't think color film saw IR, but then Idon't know what wavelengths are coming out of the mouse yet, with 'found' IRLED's.

06-30-2006, 10:12 PM
Color film doesn't see IR, but it does see deeper in red than most B&W films. Where common B&W is down near zero response by 700 nm (and some at 650), most color films have limited response out to 700 or even 720 nm -- needed to correctly record the colors of some visibly red or purple objects, objects so dim that in B&W it looks better to let them to near-black.

07-01-2006, 11:53 AM
Interesting idea, Murray. For my paper negative roll-film camera designs, I've thought of employing a somewhat similar optical sensor.

I actually built a "rev.0" of the idea several years ago, into my paper rollfilm camera that now resides permanently in the Black Hole of Chicago (another long story...).

I gutted a photo sensor from a VCR front-loading mechanism, mounted it in the rear lid of the camera to aim towards the back surface of the paper strip. The photo-transistor portion of the sensor was wired in series, with a current limiting resistor, to a red LED, which was mounted to the outside of the lid, as an indicator light.

In operation, a piece of black tape would be mounted on the rear surface of each negative, centered so that when the sensor "sees" the black (i.e. no reflection), then the negative will be properly centered to the pinhole. There was also an on/off switch, and battery holder built into the rear lid.

This system doesn't actually count film frames, but gives an idea of how far to advance the film, so the next shot is properly centered.

The end result of this experiment was that the red LED wouldn't light bright enough to be easily seen in bright daylight conditions. I didn't build an additional driver circuit to drive the LED; rather, I was relying on the current output of the photosensor itself to provide enough to light the LED.

My latest idea, not yet built, is to employ thin strips of metal foil, attached to the transition joints between sections of paper negatives. A metal roller system will read the conductivity of the metal foil and light a bright white LED as an indicator of the film being properly advanced and centered.

I'm really not sure if this idea will have more problems than its worth, or whether I should go back and perfect the IR sensor method. But its still fun to tinker.