MAS.S60
Problem Set 4
Due 10.5.12


Problem 1:  Desolder the speaker from the mystery PCB handed out a few weeks
 ago.  Do not just clip it out, the point is to give practice desoldering
 things.  Feel free to practice desolding and resoldering other parts on the
 board.  a soldering station will be setup in the resenv space for those who
 do not have access to one.  You may want to do this soon, as the speaker is
 required for problem 2.

Problem 2:  Use the speaker from problem 1, and the CDS photocell (handed out
 in class on wednesday), to make a light-theremin.  The frequency of sound
 coming out of the speaker should vary with how much light is on the sensor. 
 You can use either the Arduino, an op-amp, or both.  Bring your circuit to
 class to show it working.  Place a resistor in series with the speaker in
 order to limit its current to a max of 20mA.  The sound will be very quiet,
 but still audible.  Draw up a schematic of your circuit to be handed in.