Dot Matrix wall writer – Time writer:
Olivier van Herpt invented a machine called the Time Writer. It allows any graffiti artist in training to get their message out to the masses with the push of a button. An Arduino controls the action here. The Arduino pulses a number of relays which open and close paint nozzles. The paint mixture is pressurized using a re-purposed water fire extinguisher which conveniently has a valve just like a car tire. I think this would be a very effective guerrilla advertising technique if it was hidden under a car and used water soluble paint so that your message only lasts until the first rain.
Via Hacked Gadgets.
I think the speed is too little for mounting under a car :) Nice reuse of materials.
Would like to see a resolution increase though
This seems to be a proof of concept. I imagine once he feels the kinks are worked out the resolution is the next step. If would be interesting to see an addition of accelerometers to help keep the letter spacing / size more even.