This project is meant to fit into the ever-gowing network of sensors and ubiquitous processors becoming the 'Internet of Things.' Using a simple weight sensor in the base of a trash can, the Trashlog provides granular data about our waste habits as well as offers cues to spur environmental consciousness.
The Trashlog project began with two alarming discoveries. The first was the
Great Pacific Garbage Vortex, a huge pool of trash and debris circulating between the coasts of California and Japan. Estimates on total size vary, but there is clearly a massive quantity of man made waste floating near the surface of much of the Pacific Ocean. Samples have shown that in many parts of this gyre there is a higher density of plastic debris than plankton. Coastal areas see entire dunes built up from crushed plastic material. Bodies of birds and marine life, bloated with trash, are often found littering these dunes.
The second point of inspiration was a trash can, battery-powered and complete with a proximity sensor and motor to open and close the lid. Electrically-powered, motion-activated trash cans like this one seem innocuous at first. But consider that this can uses an infrared sensor, servo motor, control circuit, and an ever-cycling supply of 6 C–batteries just to lift a lid. If we
need to power a trash can, shouldn't we at least try to do something positive with it?
Feedback loops and data-logging, like the Fitbit and 'Your Speed' traffic signs are essential components of the Internet of Things.
Initial research explored various types of feedback loops. Positive and negative reinforcement, and gamification were considered. Providing information to the user was important, but so was making that data available to larger networks, like Patchube.
Here various display and interface layouts are being considered. It was determined fairly quickly that an e-ink display would be an ideal feedback stage. It draws very little power, a key constraint for this project given its environmental bent.
Flowcharts helped describe the basic function
The physical form is similar to existing trash cans, with the main additions being the sensor system and display. Research showed a near-even split between prospective users on the preference of a lid, so this design keep it optional. The display is integrated into a collar that also holds the bag in place. Connection to the sensor is made through connections that run up the can body.
Connecting the Trashlog to the outside world presented a challenge common to building the Internet of Things. The overhead built into (regular) Internet protocols is a little heavy for objects like the Trashlog. Standard WIFI is expensive and uses too much energy for this application. Ultimately, two solutions were devised.
For the first solution, a QR or other scannable code is shown on the display. This code can be scanned with a smartphone app that acts as the intermediary between the Trashlog and the world. Advanced interface elements can be more easily managed in this space as well. The smartphone app does all the heavy lifting, keeping the Trashlog free to supply small amounts of necessary data.
The second solution is somewhat more complicated, but also extensible. A low or battery-powered object like the Trashlog communicates over a near-field system such a X-Bee or Nordic with a wall-powered hub, which translates this information over household 802.11 to the Internet. AS these near-field systems are well proven in mesh network setups, a number of similar objects could be connected to this hub and managed. The hub system can also be spun off as its own product, with APIs for third-party development.