Code

The program for the jack-in-the-box used auto thresholding to detect the ambient light and shadows cast upon it.  As soon as the sensor detected a shadow, part of the song "Pop-Goes-the-Weasel" would be played in a loop.  There was a target count for the number of times a shadow was sensed and once it reached it, the first part of the song would stop, the "Pop!" part of the song would begin, and the jack would pop out of the box (a simple motor would turn on for four seconds in one direction, then three seconds in the reverse direction).  Once it finished moving, there would be a five second pause, the counter would reset itself to zero, wait half a second, and then wait for the next shadow before beginning the process all over again. 

Because the sensor was detecting all sorts of shadows and counting it even when the crank was not covering it, the threshold was increased from 20 to 40.  The target count was also increased to 20.  A small piece of paper was placed around the sensor to decrease the chances of other light and shadows interfering with the crank's shadows. 

In the exhibition room, the lighting changed things.  The target count was decreased to 12, but this was still a bit too much.  Six or eight would have been a better number.  Twelve was thought to be a good number so that the song would at least be played once and people could crank it as fast as they could and still hear the full song.  However, most participants cranked it slowly (I think in fear of breaking it -- which did happen a couple of times by the way) and thus made the wait for Jack to pop up even longer. 

Mentioned in the Design section was how the number of cranks would be random.  I consider the number of cranks random even though there is a target count because of how the sensor reads other shadows besides the crank.  The same number of cranks would not always "pop" Jack, so it is semi-random.

The Song:
The song played was "Pop-Goes-the-Weasel" and each note was chosen through trial and error using the HandyBoard.  Some of the notes are not correct, but the general melody is there.  Some pauses would have been nice, but I was not able to get out the bugs in the pauses, so just regular note XX was used instead (X standing for a numeric digit).  The song, as mentioned above, was split into two.  The "POP!" portion of the song was played when the motor started and Jack got out of the box.  Looping this part was experimented, but it became annoying and was left to only play once.


Here are copies of the code (including the song) in HandyLogo and Text.


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