Building special button inputs for computer

I'm thinking about running an experiment for which I'd like a special keyboard with about 4 buttons. These would need to act as normal input (preferably keys, like a,b,c,d, or something like that), but they would be a different physical experience. The idea is that I'd like to work with kids and give them a fun (probably larger) keyboard to use.

How hard/possible would this be? I could imagine trying this with an old keyboard, just rewiring it to an external device.

Or maybe there are existing devices out there?


This isn't strictly necessary, but would be better than just putting stickers on an existing keyboard...



Edit: I just realized I could run this on an iPad or something, but I'd prefer physical buttons, and also buttons that are displaced from the target locations (that is, they will see a visual stimulus and be expected to press a certain key; tapping on a screen at the location might give very different results compared to using an external button).

As far as I know, all you would need is a device and a driver. The physical thing, and some software that would make its signals make some sort of sense to the OS. You would either have to make these yourself or have them made to order. Try Googling:

custom input device

There's a third step: connecting it to the computer (such as with USB).

I have no experience with drivers, so I'd like to avoid that, and I wouldn't know where to start using USB, etc. So I'd rather just somehow extend some existing device (it wouldn't be too hard to rewire connections to individual keys), but I don't know if that would work.

I've looked through some of the search results, but most of that seems pretty complicated. I'm not looking for anything high quality really, or resellable, just something that would work in this case.


The best thing I've come across so far is an external numberpad via USB. They're cheap enough (about $10) and with (or without) modification of the keys, I think that would work fine for this. I'm still curious, but for the moment I think I'm happy with that solution.

Lots of spam is being posted here. So I'm going to close this thread. I've got some ideas to work with.