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Circuit Bending, Hardware-Hacking


Light Theremin

index
555 touch sensor
air mike
amplify your toy
box your toy
circuit sniffing
clock tickling
contact mike
electret mike
hack the clock
laying and hacking
laying of hands
light theremin
make a cable
mapping
pickup
piezo driver
resistors
soldering
sudomini
synthesis
tape head

Control a sound making chip with light.


Task 6 Name: Make a mike Set: w4 Due: w13 Weighting: logbook (50%) Courses: cbhh
Prev Task: Sudomini Next Task: Capacitative Touch Sensor
Task Summary All cbhh tasks VLE

This is a recommended project from Make Magazine.

http://makeprojects.com/Project/Light-Theremin/989/1
http://www.instructables.com/id/Light-Theremin/

and a mod:
http://blog.makezine.com/archive/2011/11/weekend-projects-light-theremin-mod.html

Parts:
Resistor, 500-piece asortment, 1/4 Watt

- Hookup wire, 22 AWG
- Breadboard, small
- Capacitor 0.22uF (220nF) (x2). You can also use one 0.47uF (470nF) (code 474) instead of two 0.22uF (code 224) caps in parallel.
	See here for help with farads (F), microfarads (uF), nanofarads(nF), and picofarads(pF)).
	See here for a capacitor code calculator.
	1uF = 1000nF = 1000000pF = 0.000001F
- Electrolytic Capacitor 100uF (code 107)
- Speaker: 8 Ohms
- Photoresistor, 5pk.  You can also try using photodiodes, too. Experiment.
- Battery holder, 4xAA, optional. Use this or other means of delivering 6v to the finished circuit
- 555 timer IC

1 - Gather together the breadboard, capacitors, speaker, resistors and photoresistor (or photodiodes).
The schematic I based this project on called for a 0.47uF capacitor. I didn't 
have any, so I used two 0.22uF capacitors in parallel. The values add, giving 
0.44uF -- and that's close enough!
We are going to be building a 555 timer-based "astable oscillator circuit." It 
sounds complicated, but really, it's not that hard.
 
2 - Install the 555 Chip and Power Lines 
Our first task is to place the 555 timer IC on the breadboard. Note the location 
of the small dot indentation (which I painted white to make it more visible). 
That dot always marks Pin 1 on a chip.
I also added the basic power lines - red is +6v, and black is 0v (Gnd).
The two red wires carry the power lines between the top and bottom horizontal 
power "rails" on the breadboard.
 
3 - Install the Resistors
Breadboard the 10k ohms (Brown, Black, Orange, Gold) resistor at the top, and the 
1MΩ (Brown, Black, Green, Gold) resistor at the bottom, as shown.
Disregard the blue color of the 10K ohms here, your resistor will likely be beige in color.
 
4 - Add the Capacitors
Add both 0.22uF capacitors in parallel.
Be careful that the legs of the capacitors do not touch!
Remember: I'm using two .22uF caps in place of the .47uF called for in the 
schematic. If you have a .47uF cap, you can use that.
Also add support wires as shown (the two brown wires, and one white one).
 
 
5 - Install the Remainder of the Parts 
Add the 100uF electrolytic capacitor
Note: Electrolytic capacitors are polarity sensitive. They can only safely go in 
one way. Note the orientation of the black band; it marks the negative lead.
Add the speaker. Note the orientation of the red (+) and black (-) wires; it 
also needs to be connected with the correct polarity.
Install the two photodiodes (second image).
You should now be able to power up the device and hear a buzzing tone coming 
from the speaker. Move your fingers towards the photodiodes, and the pitch 
should go down.
That's it! Move your fingers around the photodiodes to create different notes 
and sound effects.
 
 
6 - Experiment: Photodiodes vs. Photoresistors 
Photodiodes work in this circuit, but you can get a broader range of tones by 
swapping in photoresistors, which RadioShack sells in a 5-pack.
Try different types of photoresisor, and also try removing one of the 0.22uF 
capacitors - this will alter the range of pitches you can produce.
See and hear the Light Theremin in action here and here.




Other Ideas and Projects
You might want to have a go at some of the below instead, or investigate your own project.  
Check with me before buying too much!
Vibrati Punk Console (£20 for kit)
Luna Mod Looper
The Bit Blob 2 & Bit Blob Jr. ($25-$150)
Sound-Activated and Wearable Light Organ





to top of page The Task

  • Assemble the unit.
  • Check that it works.
  • Experiment with different parts - resistors and caps particularly.

  • Document the process with plans, photos, recordings and, yes, videos of it and of it working!

  • Media files
    You must submit media files, such as video, audio or image files, but please ensure that video files are compressed to a reasonable degree. You should never submit dv files, but compress these to mp4. You should submit no file that is greater in size than 25MB/minute.

  • Added value
    By completing the details of the task you will achieve at least a pass mark. By imaginatively and creatively considering how you might implement the task originally you can add value to your submission, and this added value may increase your mark significantly. Even when making videos of short demonstration tasks try to consider musical and performance criteria.

  • Zip up your patches, demos, photos, videos etc. into one file called your_student_number_"lighttheremin" (e.g. 012345678_lighttheremin.zip), include a readme with your name and student number and, if necessary, how to use or just open the patch.

  • Submit a copy of the files to the i-Centre by 5pm on 2pm on Tuesday 8th May 2018