Week 17, Applications and Implications
Propose a final project masterpiece that integrates the range of units covered.
- Your project should incorporate:
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2D and 3D design
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Additive and subtractive fabrication processes
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Electronics design and production
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Embedded microcontroller interfacing and programming
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System integration and packaging.
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Where possible, you should make rather than buy the parts of your project. Projects can be separate or joint, but need to show individual mastery of the skills, and be independently operable.
Cromira
Cromira is a photo effects tool that that connects to the lens of a DSLR camera to create unique in-cameral lighting effects.
What will It Do?
Cromira is a photo effects tool that that connects to the lens of a DSLR camera to create unique in-cameral lighting effects.
- Cromira allows photographers to create 3 types of effects
- Prismatic projections
- Prismatic flares
- Customizable vignettes
See sample images of these effects here
Who has done what before hand?
While I have seen a number of photographers use hacks like using CDs to create rainbows, I have not seen anyone pull this together into a singular product.
Here are some links to some photo hacks that have been an inspiration:
Here are some adjacent competitive product that focus more on lens flares:
What will you design?
I will design a lens hood that fits on the 50mm lens of my Sony camera that will have the electronics and accessories to create the photo effects outlined above. This will include all of the plastic housings, a molded silicone snoot, and the electronics that go inside of it. It will also have an app to control the lights.
What materials and components will be used?
The mechanical components will use SLA and FDM printed components and one of the parts will be overmolded with silicone. I will be using some side emitting LEDs for the vignette tool and a high power white LED for the rainbow projections. I will also be using diffraction grating for the rainbows.
There will be a variety of electrical components on the PCB including the XIAO microcontroller, mosfet, LEDs, resistors, capacitors, inductors, and a voltage booster. The system will run on Lipo batteries.
Where will they come from?
The mechanical parts will be made in the lab with 3D print material purchased from Form Labs.
The electrical components will be mostly procured from Digikey with one LED coming from Amazon.
How much will they cost?
The total cost of the build is $227.61 and the breakdown by component and material is shown above.
What parts and systems will be made?
The mechanical housings will be made in as well as the silicone snoot. The PCB will also be fabricated and assembled in house.
What processes will be used?
- 3D printing (resin and FDM)
- Waterjet cutting
- Silcone molding
- Machining (PCBs)
- Soldering
What questions need to be answered?
As of writing (10 days before presentation), the technical questions have all been answered and there are mainly some small details to be worked out in CAD on the details of the electrical housings.
How will it be evaluated?
It will be evaluated on how much it looks like a feasible final product and if it takes interesting images in the styles that I outlined above.
What tasks have been completed?
Mechanical
Some early prototypes have been created and the system layout has been completed in CAD.
Electrical
PCB has been fabricated and all systems tested and are working
App
One of the 2 functions has been created and fully vetted on the built PCB.
What tasks remain?
Mechanical
I need to update the CAD and make some refinements. I do not have a good strategy to mount the white LED yet. I also need to update the assembly to add features for some screws. Then I need to make an FDM model to validate the design before making it in resin.
I also need to design the mold for the silicone overmolding. This will be straightforward. Then I can install the LED strip on the 3D parts and do the molding.
Electrical
I need to fabricate and assemble the daughter board for the addressable LEDs so they have the pins to connect to the XIAO board.
I also need to pull the code together into a single sketch. I need to add another BLE characteristic for the white LED brightness and create some code to react to the values sent by the app.
App
I need to create a page for the app to send the brightness values from the app to the white LED.
What has worked, what has not?
Generally I have had success with the functions and features that I want.
I have struggled a bit to do the rainbow projections part of the project. It has been tricky to get the right LED characteristics and good diffraction grating that creates bold rainbows. This work was detailed here.
One thing That I could not get to work was to create in-camera flares. I did alot of testing to try to blast light into the lens to make some interesting flare effects but they proved allusive and I did not like the effects that they were making.
I never was able to make my logic level shifter on my PCB work, but it was a nice to have feature as the neopixels are stable with 3.3V logic.
What questions need to be resolved?
See "What questions need to be answered" above
What will happen when?
I was able to finish and test rev 2 of the PCB yesterday which was a major hurdle. This weekend I will finish the CAD and do some test prints to verify.
Next week I will be doing the resin prints and making and shooting the molds. I am targeting having the system fully functional on June 6 so I can take some sample photos before my presentation on June 9.
What have you learned?
I have learned a ton about electrical design and execution. That was an area that I had worked around but did not have a ton of hands on experience in.
I have also learned a bit about optics and diffraction grating. I will say my appetite is whetted but not satiated here and could be an interesting topic for future work.