My Final Project Proposal
The project I propose building for Fab Academy is an immersive interactive experience. The project is a modular geodesic dome that has mounted on the inside addressable RGB LEDs and a speaker. The user is an attendee of an interactive art gallery or museum who is interested in experiencing a sensory experience.
Week 10 progress and questions
I built out an LED PCB and a mini-mp3 player pcb for this project.
light
I used the neopixel addressable LED from week 10.
Each board requires a capacitor across voltage and ground and the tutorial on Adafruit recommends a resistor on the first digital in of a neopixel string. That being said, because the resistor only needs to be in series with the first neopixel- it would be pretty wasteful to add resistors to every board AND would add up (80 330ohm resistors would create a lot of problems for the circuit by adding that much unneeded resistance). I decided to redesign the jeffuino (now v3) to include a 330 ohm resistor on the d6 pin. This would keep the pcbs modular and allow me to add the resistor easily.
Going forward, I will need to think about how to run the data and the 5V power across all 80 some LED boards. The current setup doesn't really allow for running data in a "net" nor does it allow for adding multiple instances of five volt power to the neopixels throughout the net of LEDs.
Sound
Mini-MP3 player, using the DFROBOT DFR0299 DFPlayer Mini MP3 player.
I began to work through the project and build out a BOM. A 5/9th geodesic dome that would allow a person to stand inside it would have a diameter of 4 meters/13 feet. My campus has little space that would accommodate such a footprint. Inwould present ADA and safety concerns.
To build a3v 5/9 geodesic dome that is 2.375 meters tall (7.79 feet), would require 83 total struts (requiring 131 meters or 430 feet of material for the struts) and 61 connectors. My campus has limited space indoors to place this and my goal had been to make something that would be a permanent installation.
- The installation of the project can’t impede movement and accommodate codes.
- Has to allow for power
- Can’t pose a safety hazard
- Should convey how to use it
- I have concerns about power and the safety of the circuits I design.
The form of a geodesic dome is likely not a viable option for this project, given the space and material requirements that it wold pose. As a result, I will need to rethink the form. The goal is to immerse the user in the experience through providing both visual and auditory feedback stemming from user actions. The form factor that this could take coulud be slightly different, yet allow for the constraints listed above. I began to brainstorm alternate form factors for the assignment, listed below.
Week 8- Questions I need to answer
Fabricating and assembling the electronics for my final project will pose a number of problems.
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Quantity. If the dome has an LED in each hub in the dome, I will need to fabricate, solder, attach to the dome, and then connect in a series approximately 80 LED PCBs. Each LED PCB would need an addressable LED, a capacitor across voltage/ground, and a means of daisy chaining (input and output). I need to determine the best means of creating 80 small boards. One solution I have is based on the tabs created when cutting using the CNC. Adding tabs that don't get cut all of the way would allow me to create an entire sheet of semi-attached PCBs that I can break out as I fabricate and use them.
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Ease of assembly / daisy chaining. I need a means of connecting and disconnecting the LED PCBs to one another for power and data. This would likely involve connectors on the boards themselves and easily attachable and detachable wires, or some other way to connect each board.
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Sequencing. I had not thought about how the PCBs and LEDs would be connected in the dome. Initially, I had just thought that the LEDs would be connected in a series, but that might not be the optimal way to do so. Is this a line running around and up the height of the dome, like an inclined plane wrapped around a screw, or is it some other pattern? How I connect the LEDs will likely affect the programming and the overall effect of the lights in the experience. Do I arrange them as a series of concentric circles going from the base to the top, or is there some other means of arranging the LEDs? I will likely need to explore this in the outputs week.
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Power. I am a little rusty in this area. I will need to figure out how to power 80 LEDs, plus the microcontroller or board I will make, plus the means of input for the whole experience. I assume I will need to figure out the forward voltage drop and current used by each LED. I also think that I will likely need to use multiple power sources at different points in the LED net rather than just one running through the length of the LED circuit.
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Input. My initial idea was some form of sensor that would collect input on user actions in the dome and, based on this input, change what the LEDs do. I need to begin to think about what sensor would make the most sense, how this sensor would shape the user experience so that it is desirable, and clearly map user inputs to the corresponding sensory outputs provided by the LEDs, and possibly sounds. I will work on this in inputs week.
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Struts. I do not think it practical to CNC struts for this project and think, right now, that PVC tubing might be a better solution. The biggest issue is that the CNC and the node are 7.5 hours away. If I make a mistake or need to fabricate new struts, I have a problem. In addition, I am unsure if cut plywood would be structurally able to support the weight of the dome. PVC tubing would be lighter and the circular cross section of a PVC tube might be stronger It seems that I need to explore the question of what would make for the most cost-effective means to create struts for this project. The strut design will in turn shape the redesign of the hubs.
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Hubs. I have a rough concept of the hubs now, but I need to determine a design that will hold the weight of individual struts and the dome itself. I can use PETG to make it a little tougher. I can lighten the weight of the struts. I know that a dome will have slightly different angles for each of the triangles in the geodesic dome: the internal angles of the triangle and the dihedral angle of the planes. The hubs will need to be slightly different, some with five intersecting struts, some with four, and account for the different angles.
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Form. I need to design the dome in such a way that the form allows people to enter and exit. Given the size of the project, I might need to rethink the dome being placed on the floor, such as placing it on a ceiling or in a corner. I have to figure out what this dome will look like in the context in which it will be set up. This will in turn affect the design of the struts and hubs and the placement of the input sensors. I need to determine the viability and feasibility of the existing design in terms of the context in which it will be located and work through how I can design the user experience of the project to best accommodate the space. This might require changing the scope or concept of the work.
Research and work through the project in order to get a better understanding of how users would enter/move through it/engage with it and any ADA requriements that might need to be accommodated. Some of these questions will be answered during the input and output weeks, but how they use it will shape the design.
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Wire management. I need to determine how this project will manage the different wires required for it to work. I need to address power and data for LED PCBs, power for the main controller, and power and data for input sensors. The wires could be attached to struts or run through the struts if hollow. What makes the most sense for fabrication, setup and assembly, and the overall user experience?
Week 6 - electronics design
During week 6 I wanted to simulate a neopixel circuit similar to what my final project would use. Image of board forthcoming.
The Neopixels require a higher voltage and ampage than the RP2040 can provide. I will need to power the NEOPIXELs using an external power supply rather than through the Vout of the RP2040 as the RP2040 only provides 3.3 v through its GPIO pins. In addition, the neopixels data line also requires a higher voltage than what is provided by the RP2040. For the final project I will likely need to add a logic converter. (I need to look at the data sheets of the neopixels and the XIAO/RP2040 to gather more details on forward voltage drop, current, etc). The neopixel in the simulation was not very bright, but did flash as expected. As an experiment, I had tried running the vdd and vss from the board to each neopixel and daisychaining the data through a series of neopixels. Both appeared to work in the simulation. Good to know. For my final project, I will research whether I can daisychain power, ground and data or whether I need to power sections of the LEDs separately.
The link to the sketch is: https://wokwi.com/projects/457408666709350401
For week six our task was to design an embedded microcontroller system and check its design rules for fabrication. Based on the results of my simulation, I had intended to design a simple board that affords a "daisy-chainable" neopixel circuit that would easily connect with other neopixel circuit boards and provide the required capacitor between ground and power. The requirements of this week's assignment mean that instead I would need to build a microcontroller- not this LED board I had initially considered. I used an XIAO RP2040 and built it out to allow for inputs/outputs on the board. I will likely use this board (or one using an RP2040) for my final project.
Week 2- Preliminary Designs
In week two I began working through the design of a geodesic dome.
My initial design concepts for the hub include the following:
Early Concept work
The user would shape the colors, patterns and sounds through either movement (registered by a sensor in a hub at the top of the dome), RFID tags to choose the patterns, or possibly a mobile app.
The project would be composed of three parts- the hub which contains the sensors and the braces and connectors, which would be modular.
Brainstorming
To come up with this idea, I worked through the posted earlier projects, listing those that I found interesting. I then used chatgpt 5.2 to categorize earlier fab academy projects. My initial prompt was:
“You are a student taking the fab academy class. You want to categorize the different projects that have been made in previous classes, with the aim of understanding what is possible in the class, given the technologies taught, areas in which successful projects seem to focus, and as a means to brainstorm your own project. The URL for the class is https://fabacademy.org/2026/prior.html”
The engine asked me a few quedstions for clarification- I've prompted the engine to always ask me questions to clarify the context and intent. The link to the chat is here. There are some serious problems with the links it provided, but the goal was to help me start considering what is possible given the technologies taught and brainstorm ideas.
I then used listing and free association for about an hour to brainstorm possible project ideas or problems that I would like to solve. I reviewed the list to see if any interested me and wrote them out separately for further elaboration. I had about ten possible ideas that I could pursue.
To refine the list, I thought about how I could evaluate this semi-final list of topics. I remembered an evaluation tool on choosing ideas in a book on brainstorming and creativity (p. 181) - Keith Sawyer, Zigzag. Jossey Bass, 2013.amazon link here- not a plugThis book explained how you could plot your ideas on a matrix:
| Normal/Ordinary Ideas | Breakthrough ideas | |
|---|---|---|
| Highly feasible and useful | Not so original ideas that are highly feasible- Ideas that might be worth pursuing but would require an effective and efficient implementation plan | Ideal concepts- build it. |
| Difficult to make and unclear use | Not so original ideas that are not feasible. Throw it out. | Very original ideas that are not feasible- would need to be really high value/importance to proceed |
I plotted out my ten ideas and the geodesic dome concept appeared to be the concept that would be best suited for this project.
Materials (an incomplete and ongoing list)
| material | Qty | Description | Price | Link |
|---|---|---|---|---|
| LED PCBs | ||||
| Addressable LED | # | 22.00 $ | https://amazon.com/testoe | Order many |
| Capacitor | # | 22.00 $ | https://amazon.com/testoe | |
| PinHeader_01x03_P2.54mm_Horizontal_SMD | # | 22.00 $ | https://amazon.com/testoe | |
| Microntroller PCB | ||||
| PinHeader_01x03_P2.54mm_Horizontal_SMD | # | 22.00 $ | https://amazon.com/testoe | |
| PinHeader_01x06_P2.54mm_Horizontal_SMD | # | 22.00 $ | https://amazon.com/testoe | |
| Button_CnK_PTS636.0_6x3.5mm | # | 22.00 $ | https://amazon.com/testoe | |
| Module_XIAO_Generic_SocketSMD | # | 22.00 $ | https://amazon.com/testoe | |
| XIAOSEEED_RP2040 | # | 22.00 $ | https://amazon.com/testoe | |
| Dome | ||||
| Struts/PVC | # | 22.00 $ | https://amazon.com/testoe | |
| Hubs | # | 22.00 $ | https://amazon.com/testoe | |
| Wiring | # | 22.00 $ | https://amazon.com/testoe | |
| Cables | ||||
| Cables | # | 22.00 $ | https://amazon.com/testoe | |
| power supply | # | 22.00 $ | https://amazon.com/testoe | |
| Connectors | # | 22.00 $ | https://amazon.com/testoe | |