Final Project Week 2

Supplies

After making our foam core model, we proceeded to order materials so that we could start programming with Arduino and sketching in Solidworks.

We ordered LED lights from Adafruit:

These lights are white, so we plan to lay color films/gels over the lights to make the green, yellow and red colored lights.

We also ordered a potentiometer and obtained a NXT sound sensor from the ENGR lego cabinet. Our other supplies are the Arduino board, a 6 AA battery pack, and delrin.

Arduino

We connected our three LEDS, a potentiometer, and the sound sensor to the Arduino board. In our program, we wanted to have the lights light up based on the volume reading detected by the NXT sound sensor, as seen in the program:

We also wanted to have three different volume tolerances that can be adjusted by the teacher. Therefore, depending on the position of the potentiometer, the program would go to one of three functions: low, medium and high. Each of these functions have different sound-sensor-reading ranges for when each color light is supposed to light up.

In each of the functions, if the volume was good, the green light would light up. If the volume was a bit loud, the yellow light would light up. And, if it was too loud, the red light would light up. 

Solidworks

Once we had a basic program, subject to a lot of future testing and tweaking, we moved on to Solidworks. We used a series of tabs and notches to build a box behind the front panel, where the LED lights would be. The very back panel is also meant to have a hinge so that the teacher would be able to open the box and remove the battery pack and/or the Arduino board.

At first, we planned to use one light per color. However, we realized that the lights are rather small in size, 4.5cmx8.6cm each. So, we decided to use two lights per color. Therefore, we had to change the dimensions of the Solidworks sketch to accommodate for the extra lights. 

After adjusting the sketch for the added lights, we realized that the back panel may be too tall to piano-wire (to create a hinge). So, we decided to split some of the pieces in half, so that each half could be drilled separately.

Once we had the Solidoworks sketch done, we had to test the tabs and notches. We had to make multiple test pieces and reduced the width of the notches, as the laser cutter tends to cut the hole to be larger than specified on the file. Also, we wanted a very tight fit.


The next steps are add the LEDs to the program/Arduino board and to test the lights and program with children in a classroom. Then, we will laser cut the Solidworks sketch.

Reflection

Sketching in Solidworks was more difficult than anticipated, as we had not used the program in a while. Also, since we are using tabs and notches, the measurements have to be extremely accurate and therefore meticulous measurements have to be made. 

We tested the lights by playing a song at different volumes, but songs played from a computer most likely do not generate the same sound sensor readings as human voices do, so it is important that we do a lot of testing with people talking. 

One thing that we need to figure out is how to attach the LEDs to the front of the delrin panel and connect the wires to the back, where the Arduino board and battery pack are. We will need some kind of connectors, and possibly solder the wires.