How to detect if two items are touching when I only have control over one of them?

Question

Hey guys,

I've had an idea rolling around in my head for a while, but I can't seem to come up with a sane solution. I play a tabletop game called Warmachine. I've been looking for a while to find a way to combine my Arduino tinkerings with the game, and I have a simple concept that I need some help executing.

In the game, there are a number of scenarios it's necessary to control an object, like a flag. This flag is something modeled on top of a rounded plastic base. To control the flag, you simply put one of your models so that the rounded plastic base of your model is touching the rounded plastic base of the flag. My idea is to make the board capable of notifying the players if a flag is controlled (even if it's just by turning on some LEDs on the flag).

In this case, I have complete control over the flag. It has set dimensions, but I can put anything on it I need to make this work. The problem is, I have zero control over the models that will be touching it. I can obviously modify my own models, but not my opponent's.

What kind of sensor would you use to detect these two bases touching? Keep in mind, it can touch anywhere in the 360 degrees of the base, not just one area.

DAB · Answer

Hi Jonathan,

I can see several potential ways to approach your problem.

The key is to define what do all of your models have in common that make them detectable.

If you have just physical touching, then you can set up bumpers and switches on the flag base to tell when a model has "touched" the flag.

If the models are reflective, you can setup IR emiters and photocell detectors to trigger when a model is "close enough".

If you have position information on all of the model locations, you could do a virtual map and infer when a model is "close enough" to declare control.

So your first task is to decide what aspect of the models you want to try to detect. Once you have that answer, then you can assess which technology best fits your needs for the game.

Just a thought,

DAB