“That’s Not A Knife…”

[Robin Baumgarten] likes to play dangerously. His latest creation, Knife To Meet You cuts to the quick of cooperative gaming. 3 humans play together against the machine. The object of the game is to hold your button down as long as possible. The game makes this difficult by sweeping a knife across the play field, right at finger level. (Video below.)

Knife to meet you is controlled by a flesh eating Arduino. In addition to reading the controls and driving a servo to move the knife, the Arduino also displays encouraging messages on a 2×20 character LCD.

The idea is to scare people, not to actually slice them up. To this end, the knife is actually a capacitive sensor. When the game detects the knife has contacted soft human flesh, it stops the knife before blood starts flowing. The game indicates a player has been defeated by making several chopping motions toward the loser. If the losing player still has all their digits, a new round begins.

The project was created as part of a 24 hour game jam. The final product is quite nice, built into a wood case that closes up for travel. It even has a carrying handle, so you can bring it to parties and find fresh victims players.

We’re not sure what it is about knives and Arduinos. It was only a few months ago that we saw an Arduino driving a knife wielding tentacle. Could the world’s friendliest microcontroller board be turning on us?

38 thoughts on ““That’s Not A Knife…”

        1. Haha! Took me a minute because I don’t have Linux Unix whatever it is. But I’m so sick of Microsoft lately. I would have rather they fix XP than put out yet another OS with a pretty shell optimized for touchscreen. I want to rm -rf my Windows 8 because they screwed it up-can’t upgrade to 8.1 anymore.
          I wouldn’t trust a capacitive sensor to protect my finger! This is such a bad idea. Hope it dispenses ‘adhesive bandages’ instead of those stupid game tickets.
          On the other hand, a giant samurai blade…

  1. Does the servo have enough torque to cut? Keep in mind it is only swinging the knife so that it will make contact with the finger mostly perpendicular to it. If it were pulling the knife in/out to make more of a sawing motion, that would be different.

    I’m thinking that even if the touch sensor failed it wouldn’t really cut if you left your finger perfectly still on the button. On the other hand, when you instinctively pull your finger away you might slide right across the blade and cut yourself pretty badly!

    1. Reminds me of a harmless snake we have around here. The bite isn’t bad, the snake is small, no poison, only two teeth. If you stay calm and squeeze the head to release the teeth, you just get two small poke-holes that won’t even be visible in a couple hours. But if you freak out and flail your hand around, those teeth can slice all the way to the end of the finger. Kids learn; don’t play with the snake unless you can stay calm.

      It might be that the knife just sitting there motionless between games is a serious hazard to fingers and faces, even if the powered motion is harmless. I mean, don’t tell me people are playing this sober…

      I guess if you’re old enough to care about playing around knives, you’re too old for this game anyways. I don’t pick up random snakes I walk past anymore, either…

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