Projects

project development - Part 3

Continued from project development part 2





Step 9:
Fabricating the Housing for the installation

For housing the speakers and electronics I actually made 2 different enclosures. I made both of these using 6mm ply on the laser.

1) Firstly, I made a small portable prototype box to house the electronics and buttons for testing. This is really useful because I can bring this to a location outside of the lab and connect it up to other speakers.

prototype box for housing the electronics

Download the files for the prototype box model here





2)Secondly, I made an enclosure to house the electronics and speakers. As I'm using speakers owned by the lab I didn't want to make an enclosure that would be permanent. So I made an enclosure that would use the least materials as possible and re-use the control board from the proto box.

enclousure for speakers and electronics

Download the files for the speaker & electronics enclosure model here





Step 10:
Final Piece

Delighted I got it working. See it in action in the video below.





If I were making it again a few changes I'd make:

  • A visual output to see the frequency being output, maybe with an LCD screen.
  • When you change from a wave at the moment the frequency isn't the same. I would change this.
  • There is an amp on the speakers I used but I think I'd add an amp to the circuit if I was doing it again.
  • I would buy speakers and build a dedicated enclosure so I could have this permanently. It would be nice to use this for school groups or in museums workshops
  • it would have been impossible to carry out this project without an oscilloscope. Just a note for anyone who's thinking of doing this type of project in the future.





Design Files





Bill of Materials

  • DAC - Microchip MCP4921-E/SN, 12 bit Serial DAC, 8-pin SOIC
  • 220uF capacitor - Panasonic 220μF 35 V dc Aluminium Electrolytic Capacitor, FC Radial Series 3000h 10 Dia. x 12.5mm
  • 5 x 1k Ohm resistors
  • 1 x 2.2k Ohm resistor
  • Audio Jack - Stereo Metal In-line Jack Socket 3.5mm
  • 4 x Buttons (http://www.mouser.co.uk/ProductDetail/Shin-Chin/R13-508AL-05-BRR-L3/?qs=42TdBvIR%2FY7CICgBh63Xlg%3D%3D)
  • 1 x Potentiometer
  • Arduino Uno
  • Header pins
  • 2 x 6mm ply sheets 600mmx450mm
  • Speakers with built in Amp
  • Cling film
  • Cornflour
  • Water

Link to Final Presentation Webpage