Project Sentry
This project was a competition entry by my team #Swagathon from the HackUmass 2014 Hackathon. It is an augmented control system that allows a user to manipulate pre-programmed technology, such as MP3 volume, with fluent hand motions. We researched, designed, and fabricated the product in just under the 24 hour constraint.
General Idea
Our team of 4 wanted to automate daily functions that may seem like an inconvenience to a large audience. We came up with the idea of controlling functions of a smartphone or smarthouse without the need of a standardized interface for the user.
The example we ended up using for proof of concept was controlling an MP3 player and the audio files associated with it.
Platform
The regulated platform for the 2014 HackUmass competition was the Arduino Uno which features the ATmega328 microcontroller. We used an MP3 shield to make the interfacing and library management a bit easier. The final setup of the design was to have an armband-like attachment on the upper arm to house the Uno and shield. Wires were then run along down the user's arm to a gyroscope attached fixture around the hand. The gyroscope would capture data of the user's hand movements and execute functions based upon the motions. In our proof of concept design, the end user was able to control volume levels, skip forward, skip back, pause/play songs, as well as shuffle through a preset playlist.
Full Part List
a) Chipsets
- Polulu MinIMU-9 v2
- Arduino Libraries used for interfacing: L3G Arduino, LSM303 Arduino, Minimu9AHRS
More info on how to use the libraries are available on each github link above.
- MP3 Player Shield
- This shield features a 3.5mm audio out jack which we were able to connect directly to computer speakers to test functions. It also has a microSD slot which we used to store the MP3 files.
- Arduino Uno
- The Uno is just a simple dev board that we used to program the Atmega Microcontroller with the Arduino IDE. We used the data gathered from the polulu gyroscope and set variable constraints that allowed us to have motions of the hand that defined when certain audio functions would be triggered.
b) Other Hardware
- Arm Casing
- We ended up finding this old armband/casing thing in the back of the Umass 'Tubland'. We were able to squeeze the Uno and the MP3 shield into the casing and ziptie it together for quick assembly.
- Push Button
- Part of our design included a push button in the palm of the users hand. As we normally moved about our environment, our functions were being called accidentally because of the erratic and unexpected motions of the user. So to fix this, we had to program a reset or 'activate' pushbutton that would allow us to turn on/off whether or not we wanted our functions to work while moving our hand. This prevents the user from undesired audio manipulations.
Project Links
Hourly Breakdown
Source Code
DownloadTeam #Swagathon Members
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- Alec Bewsee (me)
- Paul Rose
- Nick Herrmann
- Neil Howarth