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Handsfree

HCI 581: P2

The Project

The aim of this project is to create a physical prototype that solves an everyday problem.

Initial Sketches


The Good Ideas

  • A bathroom exhaust that would turn on/off automatically by sensing the levels of humidity in the bathroom.
  • A toilet re-roller that detects when toilet paper has been unrolled too much and re-rolls up the toilet paper to prevent waste.
  • A "HOT!" indicator that buzzes when the bowl in the microwave is too hot to touch without gloves, to prevent burns.
  • An alarm that senses the light on a window to wake people up when the sun rises.
  • A touch-enabled light on the railings to the basement stairs, so the light can be safely turned on when going through the stairs in either direction.

The Not As Good Ideas

  • Movement enabled floor lighting to light the way in a hallway without waking adjacent rooms.
  • An automatic night light that turns on when the light around it turns off.
  • An alarm on an iron to prevent burns when it has been left immobile for too long in one place.
  • Automatic curtain opener/closer, opens during the day and closes at night using a motor and light sensor.
  • A longitudinal light fixture that is activated by clapping, one light at a time is activated so the amount of light in a room is controlled.

Refined Sketches

We decided to implement Michaela's initial idea, the handsfree kitchen timer. These refined designs are all functionally the same with respect to the timer. We decided that each LED represents a 5-minute time increment, and it fades as that time passes. Motion or sound is used to activate these designs, usually waving in front of it or clapping or snapping. When the time runs out, the lights go off, and a buzzer goes off.


Me

The countdown is shaped like a clock, where each LED light is 5 minutes. This is an intuitive and easy to read shape. The motion detector in the middle starts activating the lights one by one, and every 5 minutes it disappears. The second design is the same technicalities, but the shape is different using the Golden Ratio, starting from the center going out. I think the value of this design is that it conveys urgency as time slowly runs out through increasing LED proximity.

Michaela

Similar clock-based design, a LED light strip that is mounted on the wall, multiple LED designs wit ha colander for the base.

Max

Wheel-based design that has LEDs on the sides. Strip of counting LEDs but set around an oven.

Aaron

Lights surrounding a wine box with containers underneath. A snake-like grid that slowly increments on time based on waving.

Jacky

Lights surrounding a wine box with containers underneath. A snake-like grid that slowly increments on time based on waving.
We decided on the following design, with a vase-like shape so the container also holds cutlery. The LEDs are aligned on the bottom in two sets of 12 in 2 3x4 grids. The motion sensor is mounted inside with a small opening in the front, and the sound sensor is also inside.

Software and Hardware Implementation

We made the following. To use this, you have to make a sound above a certain threshold (a clap will work well) in order to increment the time by one five-minute increment. If you wave your hand over the motion, which requires being closer to it, the time is incremented by 5 five-minute increments, so 25 minutes.


The LED lights transition through the rainbow to show progress, and each LED fades out every five minutes. When time is up, a buzzer vibrates.


Hence we have two inputs: sound and motion; and two outputs: light and sound.

Design Decisions

  • We made it vase shaped, with a hollow top. This makes it very similar to lots of kitchen "holder" type items, so it is obvious what to use it for.
  • We painted it black since that matches most kitchens, but primarily since it makes the colourful LEDs more noticeable for the user in contrast!
  • The base at the bottom holds all the electronic components, along with the LED wiring, making it look like a cohesive product.
  • The hollow top actually uses echo to enhance the sound input! We tested the input on this and it really helps.
  • The lights were oriented in 2 3x4 grids in order to easily segment time naturally. Since each LED is 5 minutes, each row is 15 minutes, and four rows is an hour. Since clocks are segmented into quarters like that, it makes it easier for the user to obtain the time remaining from the number of LEDs that are lit up without having to count them.
  • The motion sensor is in a small hole at the bottom, and is not visible so as to make it subtle.

I tested and setup the buzzer activation, ideated and found materials for the shape, tested sound thresholds and fine-tuned them to pick up claps and reduce LED lag, and filmed the demo video.

The source code is hosted on Github. You can download handsfree.zip as well.

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