Originally it was a digital football pitch. Then a hex-based multi-section game board. Then a multi-part board game. After that proved too costly, we tried a dungeon-crawler. Creating shaped PCBs with fewer squares than a full square section, but for the same cost, seemed a bit crazy. So we went back to multi-part boards.
And so on and so on.
Each time we tried finding not just a cost-effective set of components, but also a way of assembling (or having the board sections manufactured) that would produce a viable product.
After much trying - and much to Steve's frustration, going around in lots of circles - we finally decided that it couldn't be done. At least, not in a way that would be financially viable as a product for sale.
But, determined not to give up on the entire project, it was with some curiosity that we followed up a couple of suggestions about making the whole thing "open source".
Going with the idea of making the hardware open source means re-thinking it all over again. This time we're not restricted by the cost of assembly, but more like the complexity of assembly. If we published the design files online, how likely is it that someone could pick them up and actually make one of our electronic board games? While it'd be tempted just to stick the PCB designs online and say "off you go, make one of these" not everyone has access to a bubble-tank that can etch 9" square boards, for example, nor feel comfortable hand-soldering tiny sot-23 sized components.
This has led us to re-designing the entire board game section, to make it possible for someone with moderate "crafting" skills to put one together. Wargamers tend to be a pretty "crafty" lot - making, assembling, painting and building - as they do - miniatures and terrain. But our target audience may not be quite so hot on the electronics side of things. Do we even want to try to teach a complete new-comer how to solder, let alone make them responsible for the success (or otherwise) of assembling a kit of bits?
So we hit a compromise.
We can have some (much smaller) PCBs manufactured (our original designs were massive 180mm x 240mm PCBs) and even populate them, and leave the placement and assembly of the hall sensors to the end user.
After laser-cutting some mdf, we came up with some easy-to-follow templates, for placing strips of copper tape across one of the 245mm x 245mm sections
A dab of glue holds the hall sensors in place, before they are electrically connected to the copper strips. In our original design, we simply soldered them in place.
But, recognising that not everyone might be so competent with a soldering iron, we thought we'd try (Bare Conductive) conductive ink as an adhesive. Amazingly, it worked!
Just a nice big, messy blob of graphite-based goop on each leg, and after a couple of hours drying time, everything worked just as we'd hoped:
More details on how to make your own to follow!