Knife board for Long Time Coming

Posted April 17, 2013 | 11:17 am, by nadine

The knife board came to fruition as part of the Feb Fatale game jam. I showed up with a little proof of concept for using a real throwing knife and a makey makey, but no real game idea. It was suggested by one Ms. Love that I needed to do something really weird like a dating sim. But then Sagan Yee presented an idea for a visual novel game about infidelity, and we decided to merge our concepts.

What became of it, is both a game you can play on its own, or as an interactive installation that you can operate with two people. It wasn’t necessarily intended to be a two person player type thing, but in the end, it became a really fun and well received experiment.

The game itself is a choose your own response visual-novel style set-up. What you choose will branch off into other parts of narrative.

Long Time Coming
Long Time Coming

Knife Prompt
Knife Prompt Screen

Knife Screen Options
Knife Screen Options

I don’t want to say too much about the game design itself, because I feel Sagan can speak much better too its development and style in her post-mordem (which i will link too once live), but I can say that Sagan is pretty much super woman, and that at its core Long Time Coming is a conversation orientated game, where the spots of stabbing or throwing, are metaphorical.

Also, I feel like we unlocked an artistic achievement of sorts by having the cops show up at one of our setups (knives, y’know).

So how do you make a knife throwing interface? Well I figured I’d take a tip from the wearables community and try making something that worked in physical layers.


The knife board operates like a soft switch button. It is a sandwich made of two layers of conductive material (tinfoil) separated by pieces of yoga matt foam (insulator). With a normal soft switch, you would cut holes in the foam, so that when pressed, the two layers would touch, completing the circuit and firing off a keyboard press.

materials used

In the case of the knife board, the edges of the throwing knife are conductive. So rather than pressing the two conductive layers together, the knife edge acts as a bridge between the two layers. This is effective because if you hit the board, it does nothing, you actually have to have something pierce it to work.

layers of knife board

The output is simple alligator clips and speaker wire, wired to a makey makey with a blue tooth module. Bluetooth proved to be the best option, because its easy to pair to different machines, operates well at many distances, and gets rid of possible tripping hazards like cables and wires.

materials + computer

The downside to this, is that the board will eventually get destroyed after a couple of uses, but its a good base to start building a better contact based interface from, and contact was somewhat more reliable, and a lot easier to get up and going than various range sensors. All in all, the board took less than 3 days from proof of concept to completion, with almost zero coding involved. Plus its fun, hardy, and tactile.

board done


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