This would be a frequency dectector that I had to build in a wonderful lab on flip-flops and counters.
Do notice the beautiful solder work on the back of the board.
In fact, this circuit is color coded for your convenice, as follows:
Orange Wires: +5V source
Red Wires: Ground
Green Wire: Input waveform
Black Wire: Output to LED (Turns high when frequency is less than 22 Hz)

The diagram for this monstosity is shown below, incase you feel like seeing such things:

and now for an explanation of how it functions:

          A retriggerable One-Shot (R-OS, as is shown here) produces a single output pulse of length T (where T = 1/RC).  In this circuit, R = 10 k-ohms and C = 4.7 micro-Farads, therefore, T = 47 ms.  Whenever an input pulse enters the OS, however, it retriggers the pulse of length T, keeping the output high.  If the frequency of the input pulses is higher than 1/T, then the output will always stay high.  Therefore, the JK flip-flop that has the OS output connected to the clock will not become high as long as the OS does not shift to low and set off the clock of the flip-flop.  However, if the input to the OS is of a lower frequency than 1/T, the output pulse from the OS will end, and (since J = 1 and K = 1) will send the JK flip-flop output to high.  Therefore, the purpose of this circuit (summed up) is to release a high output when the input frequency is less than 1/T.

Note: the purpose of switch S1 is to reset the output to low when it is high, since a low input on CLR will automatically set the output to low.

Another Note: The value of 1/T in this circuit is approximately 22 Hz, but this value can be changed easily by reducing the value of R.
 

     The idea behind this VI is create a spacecraft that can explore the Martian surface, and may or may not land on it if need be.  Therefore, the program will randomly generate a Martian landscape, complete with fluctuating wind speeds and possibly complete with hazards such as dust storms.  The operator of the VI will use the controls to land, fly, and take data necessary for the mission (control of the craft may or may not depend on liquid fuel thrusters, depending on what other data can be obtained concerning possible future missions to Mars).  The interface will also include monitors for the surrounding terrain, winds, fuel, craft integrity, and other such factors.
 

     In my super special project, I worked with Dr. Frank Tsui to create a 2-dimensional control system for 2 motors which would automatically move a thin film (which is created in the lab by Dr. Tsui) on the order of microns so that a detector could examine polarized light bouncing off of it and therefore determine the film's magnetic properties at each particular point.  The film is placed between the pole pieces of an electromagnet. Polarized light is shone onto the film. If the film is magnetic, the polarization chnages due to spin-orbit coupling within the film. The reflected beam is passed through an analyzer set close to extinction, and focused onto a Si photodiode. The change in the light intensity is proportional to the change in the magnetic moment of the field and the dielectric tensor of the film.

     Below is a picture of the MOKE (Magneto-Optical Kerr Effect), which performs the actions stated above:

     And now for the front panel of my motor control VI:

Follow this link to see a picture of my VI

And this is the VI in question, which you may download, if you are so inclined