For my halloween project assignment I wanted to make something that would be easily portable and detachable without the need for execessive fabric, components, or deep storage.
I wanted the LED part to make sense as an effective component that would help me communicate my costume not add an extra layer to it.
In thinking of the best scifi characters I’d seen I stumbled across a favorite that I often go back to as a reference — Eve, the robot from Wall-E.
Eve
I liked how expressive Eve’s eyes are in comparison to her otherwise sterile Apple inspired form. Not only where her eyes useful for expressing her mood and character, they also seemed to have a specific pattern of states the character designers repeated across the film. This would be perfect for my costume idea and would also lend itself to a clean detachable wearable.
Components
In selecting compontents that would work for my costume I was extra selective of visors/sunglasses that would fit the futuristic aesthetic I was lookign for but also would provide enough ‘real estate’ to house all of the necessary components while still allowing me to see.
This was the same story with lighting and while being knowledgable enough to know I should not dive into wiring together a bunch of strips, I didn’t know enough about what I should order. Again I read product dimensions for a series of different lights in order to decide what would best fit and I also did a few drawings of the different eye states to validate that and 8×8 matrix grid would work to communicate my design.
The Code
Once I ordered all compontents, I dove into the code part. After some initial research I knew that making the different eye states would be simple enough, as I’d just be telling which pixel to turn on in each of my grids — and boy was I wrong.
Setting up the Pins and Color were pretty straightforward and looked clean in the code.
The state switching to button press was also relatively straightforward even though I inititially thought we could use the native switch on the Gemma which come to find out is a hard-wire reset button.
Even setting up the eye states were pretty simple although alot of manual work trying to not mistype coordinate data for the x and y positions.
What was a challenge was the coordinate setup for the LED matrices and the way to make it work for two different light panels.
The Wiring
When I did the initial wireup test on the Arduino and bread-board I had only tested it with a single matrix, assuming it would be easy to extend the display to the second matrix. This was something I struggled with later on once wiring to my final Gemma version.
With help from Manya, I wired up my visor with everything installed and taped up nicely and to my surprise it was no longer working
With trouble shooting support from Becky, I realized it was a wiring issue. I insisted I had wired it perfectly but deep down I knew that it was too ‘perfect’ to be true. I had taped up and packaged everything so nicely that I was bound to have to go back and undo some of it.
I then realized that when wiring up my board I had been looking at the OUT nodes on my LED matrix and so the wires going IN were in the wrong order.
I rewired it…
It’s working!! Sort of….
I had one eye working at this point (and one dot in the second panel for some reason). This is the part I fought with in the end as I really wanted to tell the code my 8×8 matrix was a 16×8 matrix to basically extend the display.
While setting that up I began tweaking my states to reflect a 16×8 grid. However once setup the second eye didn’t wouldn’t display the eye correctly. The eye was always backwards or rotated or skewed in a different direction.
At one point I even ripped off the second eye and manually rotated the panel 180 degrees in the hope that it would fix this problem — it didnt and I ended up mirroring the displays which proved to be a really simple fix.
At this point I wanted something to show for all of my fiddling so I decided to continue with my original plan and add a blink animation to my eyes to give them more character. Instead of animating a blink I went with just togglign between the states and a blink state which is just a horizontal line. In the code it toggles to a blink every 6 seconds with a 250ms blink.
In the end
I learned alot from this process and while my costume looks more like a creepy NEO facotry robot more than it does Eve from Wall-e, I’m happy with the result.
If I were to take this process a step further I’d want to increase visibility in the visor while also finding a way to hook up a smaller battery in the visor to make it more self contained.