Finding a unique connector

[frampy]

Hey guys I'm in the early stages of making an electronic board game, I want the game pieces to snap together something like littlebits do http://littlebits.cc/

Littlebits connectors are pretty cool, but the aren't available individually at the moment (even though littlebits are open hardware apparently). However, I think littlebits connectors are male/female. I would like a unisex (correct term?) connector. I envision a connector which would allow game components which are hexagonal PCBs to be connected in arbitrary configurations. I would need to pass power, and 2 wires for an i2c connection between hexes.

I've been looking around and I haven't been able to find anything like this off-the-shelf. Maybe I could use something like this http://www.digikey.com/product-detail/en/70ADH-4-ML0/70ADH-4-M-ND/253419 with magnets either side. I did a quick sketch to illustrate.

I was wondering if anyone had any suggestions re a better connector? It's mind boggling how many connector there are out there.

[Simon]

what sort of connector ? if the board and pieces are pcb's you could make your own connectors with single molex pins or something.

[frampy]

Yes the pieces will be PCBs so i'll probably want a right angle connector which i can solder on.

Do you know if molex sells any pins which would be suitible for a unisex connector?

[Simon]

well if you use single pins and combine male and female in a symmetrical layout you can plug the pieces together as well as to the board, but it means you will have to double up pins. Why do they need to be "unisex" ? won't the pieces be plugged into the board only ? why do you need to plug the pieces into each other ?

[amyk]

I think the term should be 'asexual' connector.

[Simon]

I think political correctness dictates "pin" and "receptical" just to make engineering boring I don't think they have come up with a pc term for asexual though ..... Yet

[frampy]

The game will be similar to "settlers of catan", the pieces essentially are the game board. They need to be capable of connection in arbitrary formations. That's why i thought a magnetic connector would be suitable.

[Simon]

have no idea what "settlers of catan" is

[david77]

Isn't there a way to use tiny magnets as contacts?

[T4P]

http://dx.com/p/super-strong-rare-earth-square-re-magnets-30-pack-51742?item=3
They actually use it for flashlights 

[Astroplio]

I believe if you go down the route with the magnet idea you will eventually need to fabricate your own special connectors like littlebits did.
And having 6 of them in each board you will need to order a lot of them, so to have enough for the first set of games, and the total cost could be huge. (I don't know the specifics of your idea but this is something important to consider!)

There is a way you can go cheap by using existing connectors and short lengths of ribbon cable.
The disadvantage is that the user (the player) will have to add the wire to make the connection.
Also might not look as pretty as you would like, unless you use rainbow colors... 

[ejeffrey]

Easiest way to make a hermaphroditic is to take any normal connector and place two side by side -- one male and one female.  You could do this with standard pin headers/sockets, or any of your typical molex/amphenol/whatever board-to-board connectors.  The other option is to create a 'bridge' component that connects two identical connectors.  The simplest example of this would be to use flat-flex connectors, and then the cable is the bridge.  You could also use vertical pin headers with small 'bridge' boards that have two pin sockets on the bottom.  A little clunky, but cheap and effective.  Depending on how the bridge is constructed it could also act as a cross-over cable to avoid having to double up some of the connections.

The two big problems are going to be insertion force and registration.  Anything that requires lateral force to insert is going to be difficult to assemble without disrupting the other tiles.  It will also be quite difficult to insert a tile in a slot that already borders 2 or more other tiles.  If you don't have anything that gives, you are going to have problem with registration.  The more tiles you add, the more alignment errors in the individual connectors add up and will make new pieces not mate perfectly on every edge.

I am not a fan of using magnets as the actual contacts.  Without some springiness, it will be quite difficult to make sure they make contact, at least if you have more than 1 or 2 "pins".  On the other hand, using magnets to hold the pieces in place could work fairly well.  How about a row of pogo pins and pads, with a pair of small rare earth magnets on either side to hold it together.  You will still want some mechanical guides to provide lateral alignment, but they don't need to be a tight fit.  Make sure you get N/S oriented consistently!

[cwalex]

The other problem with rare earth magnets is that they require a lot of force to separate them so they would need pretty good support at the PCB. It might work better if you can make a large game board with hex cutouts for the game pieces to sit in so that you can use weaker magnets or magnets behind a spacer of some plastic or other material with the contact on the other side of the plastic to the magnet so the force to separate the game pieces isn't so great.

[xquercus]

Anderson PowerPoles are genderless though I'm not sure they are otherwise appropriate for your application:  http://www.andersonpower.com/products/singlepole-connectors.html

[frampy]

Easiest way to make a hermaphroditic is to take any normal connector and place two side by side -- one male and one female.  You could do this with standard pin headers/sockets, or any of your typical molex/amphenol/whatever board-to-board connectors.

Yeah this could be an option. At the moment I'm thinking I could construct something like this using pogo connectors.



Each of the four connectors is duplicated which is a bit redundant, but isn't redundancy nice in a toy which might be plugged in and out many times.

I believe if you go down the route with the magnet idea you will eventually need to fabricate your own special connectors like littlebits did.
And having 6 of them in each board you will need to order a lot of them, so to have enough for the first set of games, and the total cost could be huge. (I don't know the specifics of your idea but this is something important to consider!)

I wouldn't know where to start in getting my own connector fabricated, and I'd rather avoid it if possible. It would be really nice if I could find a good magnet which can easily be soldered to a board. I haven't been able to find any through hole magnets, maybe I could just solder those dx magnets previously mentioned directly to some solder pads on the top of the board.

[Someone]

If the design can accommodate the parts having a fixed orientation with regard to the world, Molex parts 22-14-2044 and 22-05-2041. Its a bugger to build the PCB with those hand placed parts but should be quite robust and dirt cheap.

[bfritz]

Why reinvent the wheel?

If you want something like the littlebits connector, why not just buy the littlebits connectors?

I bet that if you contacted them, and your use didn't compete with their business model, that they would be happy to sell you connectors.  They could make a small amount per connector, and pay for their effort to design and get them manufactured, and you would get what you need!

I would try contacting them through contact info on their website.