The Arduino can be used for many things when It comes to R2. The lights is a good reason to use one, as it makes them flash and do all sorts of interesting things. I have the Arduino Pro Mini and it only cost about $10. This is extremely inexpensive for something that does so much for our little droid.
You will see above is the Arduino Pro Mini and attached to that in red is the FTDI Break out, used for uploading a sketch to the Arduino. The sketch controls the lights and what they do.
I used a tablesaw to build my coin slots from wood, with a drill press to route out the depth slots.
The first thing I did was draw the slots out on a block of wood. Measure twice, cut once! Measure the whole thing to make sure it all lines up because I had issues with the way I did it the first time.
Once trimmed, I work in reverse on the table saw, pulling everything towards me from the back side so I can see my lines and make sure Im on the mark.
I start by creating the upright portions of the slots by marking the wood on the side so I know what to cut and not cut. Be carefull of what side your blade is on when you do cut, otherwise you will ruin your work. The squiggly lines represent the sections that need to be removed. Alot of lines can get confusing, so I tried to make it simple.
I cut the uprights first. Working slowly and making sure I was on the proper side of the line with the blade when cutting them out. The squiggly lines came in handy so I knew what side I needed to be on.
I then angles the blade by doing some math to figure out what the angle should be per the plan. My saw only allows the blade to angle in one direction, so I can only do one set of uprights at a time. I then have to flip the piece to do the other side. The advantage to this is that the blade stays at the same angle.
After the uprights are cut, I angle the blade again for the sides along the length of this piece. I used some double sided tape and extra boards since the wood gets smaller and I didn’t want to loose my fingers.
I separated the piece from the rest of the wood and routed out the slots with the drill press. I drew a line down the center of each slot and slowly moved the drill press along the line, going deeper each time, and periodically clearing out the wood shavings.
This is what the final piece looks like without any paint.