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membrane button recorder

Posted: Mon Jan 07, 2008 4:38 am
by projectpat
OK i posted this is the wrong section and now my friend that needed this project wants me to find someone that will build it and pay is involved.
Whats is needed?
it is a membrane that is the size of a calculator that when placed over the keys it recorders each key pressed to a 512k memory chip and will store info with a time and date stamp and can be downloaded to computer via usb cable.
Any takers? or anyone willing to point me in the right direction?


Posted: Mon Jan 07, 2008 7:44 am
by Sambuchi
I see your project as... doable.
Doable in terms... if you have the necessary hardware that "can be placed over the keys that can communicate to a micro".
I dont see this being easy... if starting from scratch.
The firmware needed to do this should be standard stuff.

Is it possible just to write an application that will run in the background... storing all the data to the computer? seems more practical.

Posted: Mon Jan 07, 2008 10:52 am
by haklesup
Electronically speaking, such a device would be no problem for anyone experienced with a PIC or uController. The real challenge is in making what you describe as a membrane and associated product packaging (the case). If you want something flexible and transparent, I don't know of a technology. If you want clunky mechanical button extension to overlay, that seems possible. Maybe an optical device without a membrane or contact surface, just detects the position of a finger.

Frankly, such a device if packaged properly (stealthy) could be used for unethical purposes such as stealing PIN numbers. But there are plenty of legit uses too.

Assuming he has a decent budget, he should look for an engineering product design company. There are lots of them all over the world who will take your idea and produce a finished product as fast as you want to pay them. If he's thinking he can DIY it for a couple k$, he's in fantisy land. Just google "electronic design company" or something like that to find them.

Posted: Mon Jan 07, 2008 12:33 pm
by Externet
Pat: There is a virtual keyboard which is just the projection of the image of a keyboard and you type on the image... If it works on a desktop, should work projecting the image on top of another 'normal' keyboard.
Needs no membrane to build the hardware for your project.

Makezine or Hackzine has an article of a guy who removed the film sheets from inside a membrane keyboard and attached it to his desktop surface, and works, there is pictures of it. The result is a 1mm thick keyboard. Do a search to see it.



Posted: Mon Jan 07, 2008 1:41 pm
by projectpat
My friend is a Magician/Illusionist he has an idea for a mentalism effect for magic. Believe me this project is for ethical purposes, it for entertainment. I guess whoever do wish to take on this project would talk to him for the details.
He has a lot of good ideas, the price on bringing them to reality...hmmm I dont know.

Posted: Mon Jan 07, 2008 1:53 pm
by haklesup
Then by all means have your friend join us here. Your description is just a bit too vague to get useful answers.

If he wants something virtually undetectable he can use anywhere, I think an optical solution is the only way to go. Either a variant on the virtual KB or some kind of machine vision camera/computer thing.

If the keyboard is not built into something, one could build a gadget to go in line with the cable to store the keystrokes.


Posted: Mon Jan 07, 2008 2:27 pm
by projectpat
I will get him to logon here so he can explain in detail whats needed, thank you all for your feedback and time.


Posted: Mon Jan 07, 2008 3:50 pm
by bodgy
How about buttons that work by capacitance?

Both Microchip and the PsoC people have a development notes and boards. There are also the pre-made capacitance sensing IC's from Qprox.

Once the PCB buttons have been made then any covering you like (within reason) can be used, alternatively perhaps a cheapo keyboard could be pressed into service.


my project

Posted: Mon Jan 07, 2008 7:54 pm
by projectpat
we looked and came up with something a bit close such as:
and kit: K164 Kit 164 Telephone Data Logger

If it can log the #'s then we will know what the #'s represent is there anyway to convert this unit so that we can just have it so that we can use just a telephone keypad and keep it portable?