Light my Fire A control with intent

fire starter control

Project Description

What gesture do you do when you are feeling cold? Chances are, you are rubbing your hands together to create friction that warms them up. This gesture has been a part of the human vernacular since we’ve been making fires. Is it a coincidence that the earliest tools for starting fires involved the same gestural control?

Now when we turn on the heat in our homes we rely on the meaningless interaction of pushing a few buttons or rotating a dial… even gas fireplaces are often controlled via a switch on the wall—one that looks no different than an ordinary light switch.

I want to empower that instinctual expression of the ‘intent to be warm’ by having a control for a gas fireplace or other localized heating system that captures that gesture in a way that can be translated into a corresponding value representing the desired intensity of the heat source. This could raise the temperature setting of a thermostat or increase the size of the flames in the gas fireplace. Either way, the inherent feedback corresponds directly to the user’s expression of intent.


The prototype seen here was built entirely out of scraps of acrylic, wood, and metal found in the physical computing lab at CMU. I used Adobe Illustrator to shape the pieces and cut them with a laser. The model is held together with screws and some ever-handy double-sided scotch tape.

  • Acrylic
  • wooden dowels
  • OpenBeam frame
  • Scotch tape
  • laser cutter
starting fires with sticks


I knew my design was working when my classmates walked up and started rubbing the dowel rods between their hands without any prompting from me. The object afforded the proper interaction without instruction from me; moreover it was a surprisingly pleasing interaction to engage in!

Next Steps

There are several things I’d like to do to take this project further. The first is to get a sense of the kind of voltage that could be generated from an inductive motor wired to the dowels. I have some experience using hobby motors as inputs for micro-controllers, so I know I’d have to experiment a little to make sure I was getting a consistent signal from the ‘rubbing’ action. Once that is accomplished, I would then find a monitor that could provide feedback to the user of the device to create a more realistic setting for testing its effectiveness as a control. This would of course raise new challenges to tackle, such as how it turns the system off...