Final Project Week 2

Partner: Katrina Montales

This week we finalized our order plans and worked on a mockup of our first prototype.

Material Order Plans:

• We already have all the legos that we could need (stored in the lego cabinet)
• weight sensor --> color sensor --> light sensor

• The weight sensor was phased out of our plan, we decided we no longer needed to sense the weight of the marble, but have it release a marble on the set time interval.
• The color sensor was prohibitively expensive ($40 of our $50 budget) Although Amy offered to buy it outside of our budget because she could use a color sensor in later classes, we found a way around our problem. Necessity breeds innovation, right?
• We are trying to see if, just based on the sensitivity of the light sensor, figure out when the compartmentalized marble holder needs to be shifted over
• We want a clear pipe to hold the marbles so we can see the various colors that correspond to the duration of different activities. The diameter of the marbles is approx. 9/16'' so we need a tube that has an inner diamater between 10/16'' and 1''.
• 3 total motors + Arduino + Bricktonix shield for controlling the motors and feedback from the light sensor
• Lastly, we need various colored marbles (to represent time)! 

Initially, we tried to minimize the number of motors needed to power the shifting mechanism. However, this would not have been possible with the way that the marbles fill the second container (orange).

So we created a model that has two motors shifting the marble containers, pushing them in opposite directions!

The second problem we tackled was using a light sensor. We needed to find a way to have the light sensor sense if there are were marbles left in the tube, or if it should shift to load in the next activity's marbles. 

Ideally, we would be able to have a light sensor right underneath the stack of marbles that could point upwards and sense if there were any remaining marbles that needed to be released. However, given the size and shape of the light sensor, this was not an option.

So we devised a plan to have the light sensor be shifted off center. With this plan, we would have to build up some legos on top off the face of the sensor so to protect it from marbles falling directly on the sensor. The idea behind this plan is that when all of the marbles of a specific color run out, then the light sensor will sense a high light value and shift the marble container over and release the next activity's marbles.

Alternate plan:

Attach the light sensor to a point behind the releasing mechanism so that when the light sensor senses that there is no marble there, then it will shift over the marble container (and also the bottom marble container).  If this doesn't work, we discussed using an ultrasonic sensor to sense the distance to the nearest object for marble detection. All trial an error, but hard to do without actual marbles!

In addition brown platform underneath the top container is fixed, functioning as the bottom of the marble container. However the marble container itself does not have a bottom, so that it can be shifted over, releasing the marbles simply through the use of gravity.

Also, I wrote out some pseudo-code for planning out how we should approach each part of our project. I find that it is much easier to take apart the problem in english, and then translate that into code rather than trying to balance it all in my head at once.

Thanks for reading! I'll update you again in a within week!