About this project
Reasoning about time by printing onto the surface of a river
Maybe you know situations when time’s running up. In German there is a metaphor for that and translated it would be something like “time trickles away“. Having this saying in mind and thinking of how to ‘imagine’ time the following idea turned up:

I would like to generate a situation, where people are able to let time pass by without getting into a hurry. Therefore the digits of time get printed onto the surface of a river with food colouring, so time could be observed from a bridge in peace, while it trickles away.
This idea got realized September 2013 in Innsbruck, Tyrol.
Electronics & Hardware

How it all works
The core element is an Arduino. It receives the current time trought a Real Time Clock Module. The micro controller maps the numbers of the time onto the available 5×7 pixel grid per digit. The resulting vertical lines of drops get printed one after the other by switching the shift registers and thereby the pumps. The Arduino code and the wiring diagram were done by Albert Frisch and could be found on the projects site on GitHub.
For logging what’s going on, a Raspberry Pi receives status messages from the Arduino. Once in a while – on an average every 20min – fswebcam gets called and takes webcam images as fast as it can for about 40 seconds. Afterwards the images plus log files get uploaded to a Server with fixed domain via a GSM-connection.
Read More: Flow of Time