Tiled PCB connection

Community PCB Design
1

I’m designing a little project which involves lots of square PCBs that get tiled together and communicate with each other in a de-centralized fashion. My question is about designing the interconnects. Each tile (pcb) will have (probably) 12 connections on each side (tiles can be rotated in any orientation and will still behave appropriately).

How would you design these connections so that each tile can be placed and connected easily, without wires or extra parts.

Things I’m imagining:

  1. vertical pads the protrude slightly from the edge of the board with a magnet to hold the tiles together

  2. perform all communication with IR photodiodes/leds

  3. some sort of inductive coupling? (would need to be tiny, might get noisy with all those connections?)

The criteria for a good solution:

  1. Cheap: as cheap as possible

  2. Readily available: goes hand-in-hand with cheap I think

  3. Physically reliant on PCB only: Although these tiles may eventually be cased, the interconnect shouldn’t rely physically on the case in any way

  4. Should not protrude from tile very much: The tiles should be connectable easily in any configuration, sliding a tile into an inside corner, dropping a tile into a hole, etc. This precludes pins and sockets.

Anyone know of anything like this that’s commercially available? Perhaps some battery tabs that could be mangled to this purpose?

2

The easiest way and prolly secure also, would be to use male headers on one then female headers on the other. But that depends on how big the boards are, weight, and how they will be mounted.

3

You mean like this:

http://www.seeedstudio.com/depot/bsquares-c-205.html

4

Can you do something with very small magnets in a molding?

http://www.waylandgames.co.uk/expert-te … 11700.html

They would hold it together and make electrical contact.

That way there is no male/female differences,

5

mattylad:
Can you do something with very small magnets in a molding?

http://www.waylandgames.co.uk/expert-te … 11700.html

I like that idea - you could glue them to the PCB pads with conductive adhesive (do NOT solder them!).

BTW, you can get them a lot cheaper on EBay, which has a vast array of rare earth magnets on sale, eg:

http://www.ebay.com/itm/50x-Neodymium-D … 27ca4b06a7

6

IMO it would take a custom molding, with some metalized connections that the magnets push onto to make contacts from PCB to magnet.

But it would enable them to be simply clipped together and boy - would it be hard to break that connection :slight_smile:

7

Just curious - why don’t you think simply glueing the magnets to the PCB with conductive adhesive would work?

8

MichaelN:
Just curious - why don’t you think simply glueing the magnets to the PCB with conductive adhesive would work?

Make sure to polarize the magnets so they will properly mate. This is how most electronic building toys work, with the magnets arranged so that only the correct connections would mate.
9

About ten years ago I saw a presentation by Mitch Resnick at the MIT Media Lab where he showed some cube shaped “gems” that communicated by IR with each other. The objective, if I remember correctly, was to make interactive jewelry where they would light up in different patterns depending on which side was talking to which. I don’t remember what they were called, but I remember that there was a good description of how they worked on the Media Lab home page.

It was a good talk and got me interested in the concept of autonomous agents.