The Design Process

The idea was floated as part of the brainstorming session in the IoT class. We liked the idea of connecting spending data to the water level in a fishbowl. The mix of playfulness and severity of the consequences, is a persuasive tool for influencing people.

Initially discussions centered around the nature of data that the fish tank would react to. Two clear alternatives emerged. The first idea was to display water level as a function of remaining balance, in a mentally accounted monthly/weekly budget. The second alternative was to collect aggregate data, and display a trailing average weekly/monthly spending. We decided that having a "reversible" water level, was more persuasive and positive than a constantly falling water level.

Iterations

In our first iteration, we weren't confident about making the pump flow in both directions. We planned using a servo/solenoid valve to operate a latch within the balancing tank. This design imposed constraints on the form and design of the device.

Challenges

Finding the right amount of resistance to offer, to input a value into Photon was challenging. After much experimentation, with the number and type of resistors, we were able to create a functional sensor.

A lot of time was also spent linking the photon to google sheets, via RSS+IFTTTT, since this was our first attempt in downloading information from the web.

Another challenge, was to identify the right hardware to operate the pump in both directions, we eventually stumbled upon the dual H-bridge controller in the ideate lab, a quickly figured out how to wire it up.