I am really happy how the construction of the meditation pod turned out. At first I was a bit weary of using OSB, but due to thw fact that it was provided in the shop I decided to take advantage of it. The pieces came to gether nicely without too much difficulty. In order to construct the pressfit nature of the pod I started building all of the vertical levels along one of the S curves. I added an opposite S curve for supports and then built around from there. I see this pod as being very modular so the press fit aspect is nice to construct and deconstruct with ease. Due to the limitations of our Shopbot bed - it can only cut 4x4 pieces - I stuck to keeping this a smaller prototype. As you can see from the picture, this iteration would not be conducive to an adult meditating inside of it - unless the adult found claustrophobia beneficial to their practice. I designed some externl leaves in Inkscape and cut them out on the laser cutter. One of the prototypes can be seen above. When fit the leaves against the pd I found that they were too short for the structure - again this was due in part tot he bed limitations at the Harvard shop, although if I wanted to pursue laser cutting I could seek to use a larger laser cut bed at a neighboring science lab shop.
Earlier in the semester I designed a new button board with 9 buttons. I selected 9 buttons as it was a number divisible by 108 - amount of times one counts around a meditation necklace. As I had mentioned in my input device post, I had some trouble with the reset pin on the ISP. To circumnavigate the issue I attached a wire between the resistor and the reset pin. I decided to leave this version as is for my final project as I think it nicely shows my process. Speaking of process, at one point in my final project development I thought of instead using the button board I would use a mic to pick up sound from the meditation and have it interact wtih lights. To make the second board I simply added a switch to Neil's mic board.
I wanted to find a way to hide parts of the electronics for my final project. I decided to try a few different techniques. FIrst I attempted to cast in silicone. I hadn't used silicone before so it was a fun learning process. Somethings to note about the process - planning is key! Have all of our tools and work surface well prepped. The work time on the silicone is about 6 minutes or less so you'll want to move quick. I used the Mold Star materials in the shop. I found it best to mix equal parts into a large cup. I then used a stirring stick to work the viscous material back and forth until incorporated. During one iteration I tried to use a vacuum to bring out the bubbles. However, I wasn't too pleased with the end result. I found it to have more tiny bubbles even though there were less larger ones. The process I found that worked the best was to take your time and be very patient and diligent with the hand mixing. I spent about 3 minutes stirring so it left me little time to work my molds. I wasn't too thrilled with the results of the silicone on with my OOMOO mold so I tried some 3D printing
One of the challenges with the silicone I realize was that the electronics became embedded in the silicone and not easily accessible. I started to think of some alternate solutions so I landed on 3D printing. I thought it would be need to print a container that would have threads so that it could open and close like a tupperware container. I built off a file I found on Thingiverse by making adjustments inthe dimensions and some aspects of the design. Initially I tried unsuccessfully to print on the Makerbot. Later I got some time on the Ultimaker and printed the container in red you see pictured above. The quality difference between the two prints was staggering. Definitely a big fan of the Ultimaker now!!!
One of the issues I was having with the cure of the silicone was that it was remaining sticky when interacting with the OOMOO. I found out that this is because the silicone and the OOMOO are not quite friends. I figured the quickest way to cast the medallion would be to remill the wax mold. In order to do this I had to mill the OM in the mirror image and in the negative so that when the silicone was poured in it would sit in the mold the way I had wanted it to sit in the OOMOO. This whole adventure ended up being quite the deteour as it resulted in me using the desktop Shopbot for the first time. Although I could have milled the wax on the Modella the task would have taken hours. Instead I elected for the desktop Shopbot, but since I had never used this version it ended up taking hours to figure out. I was glad I went through the process as I learned a great deal about how to interface between the fabmodules and the Shopbot software. Once I got the project going - with Rob's help of course - it did not take much time. I used a 1/16 endmill so the result was beautiful even for a rough cut. The tool was able to pick up the instricacies of the Sanskrit script quite nicely.
The remote board although cool looking was the most user friendly. I set out to design an ergonomic alternative. As I wanted it to fit nicely into my hand I decided to use the molding clay to make something that matched the curvature of my hand. This turned out to be more complicated that I thought (surprise, surprise). First, I spent some time created a form that matched my hand. I also needed to form to be big enough to contain the remote board. There were some key components of the board I would need to protect when casting. Most important were keeping the FTDI pins exposed. In order to protect them during the casting process I rested them on the lip of the form and created a tent out of clay to block the component from the rest of the board. I checked security of the component by looking through to make sure there was no light passing through from the back of the header. Next it was important to protect the buttons on the board. I was afraid if the silicone got too thick on them they would get stuck or stop working. As I rested the remote into the silicone I held it place with a thin metal wire. It suspended in air for a bit as the silicone began to set. I gently lowered it into the silicone at what I preceived was the right time in order for it to adhere to the silicone and yet not overflow.
I knew I wanted light to be a part of my final project concept. I elected against sound as I find in meditation that your own sound and the vibrations it creates is powerful. I thought light could be a way of enhancing the experience. Therefore for project I elected to purchase some Neopixels from Adafruit for about $8. The 12 ring was perfect in size for my project as well as it worked with the math of the meditation necklace. The NeoPixel is really easy to program with an Arduino. They provide libraries with sample code to work off of. Initially I was trying to use this in conjunction with my mic board, however, I found the Neopixel requires a crystal when paired with the tiny45. Instead I paired it with my button board. The mega on the board is compatiable with the needs of the Neopixel. It was challenging to get the lights to behave in the way I envisioned. First I wanted each led in the ring to correspond with a button. Next I wanted the lights to clear once one pass of the buttons occurred. Third, I wanted the increasing color variance and brightness to be a visual cue to the user tha they were getting deeper into meditation practice. Lastly, I wanted there to be a festive cue to show the conclusion of practice. Dan helped TREMENDOUSLY with figuring out all of these specifics. Above you can see a picture of a snippet of the code highlighting how to program the neopixel.
In this first video you will see the remote and neopixel interact to show the programing of the neopixles.
In this second video you can see how the neopixel response looks once it is cast in silicone.
I don't think I could have got to the finish line of this project without the patience, guidance, and support of the talented, Dan Chen. I am so thankful for the generosity he showed me with his time and for explaining new information. In particular, thank you, Dan, for all of your help programming the neopixel. It was challenging to figure out how to get it to match the vision I had for this device, but we got it.