Hi.
I am looking into buying one of your kits for the coffee table however I am looking to customise it a little.
I intend to use this a a wall feature on my stairs so that when people walk past it lights up and reacts to them as they go up/down.

- Would I be able to order (from you) different shaped boards. Nothing fancy just triangles. This is because obviously stairs are not level and I would prefer the panel to have vertical edges to the left and right but the top and bottom to slope up with the stairs. (similair to a rhombus shape)

- At what 'range' do the sensors react in an artificial light enviroment (rough guess)? My stairwell doesn't get much natural light.

- Would the system still work behind dark tinted glass? The effect I am after is that it will be like a jet black panel until someone gets close to it. Also would this work with mirrored (maybe one-way???) glass. I havnt decided yet.

- What sort of power does this device suck up? Would it be possible to run it off of a battery pack of some description? Drilling a power supply to my stairs would just upset my girlfriend and she the reason I'm getting a kit that means I can lock myself in the garage for days on end; get what I mean!

How much roughly, would these mods cost? More exact figures to be discussed in private obviously.

Many thanks

Customizing the shape of the boards for small runs is not really a viable option unless you are quite wealthy-- it can raise the price by a few k$. There's a lot of engineering time that goes into laying out a new circuit board. After that, actually having the circuit boards made in the smaller quantity would cost (at least) twice what it does for the larger production runs that we do. (Both are more work than you might expect.)

Motion sensing works in two different ways. First, the sensor can "see" sunlight and light from incandescent bulbs, so it responds well to shadows, and if you have a halogen light tens of feet away and walk between the two, you can interact with it entirely on that basis. To work as a proximity sensor, we also place a bright (but invisible) infrared LED by each sensor node, providing light that can be reflected (e.g., off of your hand) to the sensor. This works pretty well up to a few inches above a frosted surface, sometimes up to a foot above a clear surface. One interesting side effect of our design with the IR sources: If you had two set of panels on opposite sides of a (not *too* wide) hallway or stairway, the infrared sources from each side would cast good (invisible) shadows onto those on the other side.

The boards work very well through a frosted top, either glass or plastic-- that's usually how they are mounted. However, they *do not* work well through a dark surface. It limits the sensing and it limits how much light from the LEDs gets through. (Obvious, no?) The solid black boards do a pretty good job of imitating a black surface, you know.

A set of 8 panels, at its very brightest, draws about as much power as a regular light bulb. You wouldn't want to run a regular light bulb on batteries, nor would you these circuits.

-Windell

Sorry cannot login whilst at work.

First thank you for the reply, however with some further brainstorming I have some further question.

Am I right in saying that you are still out of black boards? The new version coming in April; what will this be?

The kind of glass I intend to use is similair to that used by magicians. It is nearly opaque until a bright light is lit behind it when it appears to be transparent and anything behind becomes visible. I was looking for advice on the effect of this glass on the sensors. I have also sent an enquirery to the glass supplier, but they seem rather clueless as to what I'm on about.

I don't have any way of mounting two seperate boards opposite each other however I can put an IR light bulb up in the stairwell. Providing this bulb is 'strong' enough to cast IR shadows on the circuits would the sensors pick this up or does it have to be a specific 'type' of IR (may sound stupid but I know very little about IR)?

My experience of electronics is taking things apart and ripping parts out of them to create (slightly) mischievious things i.e increasing the power of my CB radio, without realising it would set my desk on fire or building timer circuits. cough cough. This project seems to be tons and tons of soldering; anything else that I need to study/buy?

Once complete what will be the depth of the boards and components?

Regards

The Evil Mad Science shop is currently out of black boards, it's true. New boards are coming in towards the end of April, with some design changes. We'll post details sometime around then.

The easiest source of IR to use is a regular incandescent light bulb. Dim ones work well. Otherwise, use your own IR LEDs.