Is it possible to associate patterns of movement to cat emotions and desires? How best can this information be displayed? The Telepathic Cat Vest is a combination of two different inspirations, the design of readable low-resolution digital typefaces for LED matrices and the idea of animal wearables. Part of this project is to explore how technology defines ourselves in relation to non-human animals. Does it help or hinder our interactions? Is the final form pure entertainment or can there be some further explorations that would be useful?
Using an accelerometer to trigger phrases on the side of the vest, two LED matrices are chained together to display two-word phrases such as “Feed More”, “Bird Yum!”, “Oooo Mice” and “Stop Fool”. Each phrase is connected to a different level of motion on the Y axis of the accelerometer. Constructed out of a jaunty orange cotton/polyester fabric which would also work to make cushions for a hunting shack, the vest has a detachable zippered pouch containing all the electronics and power supply.
This diagram is based on the wiring in the LED matrix tutorial on the Adafruit Learning Center.
Download the cat-vest-circuit-diagram. (PDF)
Three versions of code were used for testing different stages of the cat vest. As there was a delay in receiving the LED matrices, I started with testing that the accelerometer could turn on three LEDs at different levels of motion. Once I started working with the matrices, I used the default typeface to test the position of the four phrases.
Download these three versions in the cat-vest-code PDF file.
Process and Documentation
The cat vest originally was planned to be built from two separate pieces of fabric, a top section and a bottom piece. However due to the squirmy nature of my friend’s cat, I realized that having straps secured by velcro or snaps would be easier to put on and take off. The first fabric version, built from an old t-shirt ended up looking like a tube sock. I switched to a more rugged outdoor fabric, and built the vest from two layers that were hemmed together and then turned inside out and top-stitched, to look tidy.
The orange fabric diffused the light from red LEDs nicely, and even with the addition of a thin layer of cotton to line the zippered pouch, showed through without losing much definition.
The above photos show Bullseye the cat modeling version 4 of the vest, which led to a thinner neck strap and resizing of the front leg holes. The need for these design changes can’t be seen in the photos as Bullseye was too busy wondering where her electric squeaky toy mouse had gone to pose properly.
Initial wiring on a breadboard shows the set-up for testing the code for the accelerometer to trigger different sets of LEDs. Once this was working, I knew I could replace the code to turn on the LEDs with the code for the text on the LED matrices. The second image above shows the pile of cables that went into the zippered pouch, I knotted similar groups of wires together to prevent them from tangling.
Initializing the matrices to test how they worked chained together. The phrase “Bitch Please” turned out to be a little too long for what I had in mind.
Different sizes of pouches to contain the electronics. The middle version with the yellow zipper turned out to be too short to allow for each LED matrix to hang down far enough on Bullseye’s sides. I made a custom 10-pin cable and a longer pouch, the version with the pale green zipper. The matrices were very bulky even when they had more room, so perhaps future versions of this pet vest could use thinner screens, or maybe the vest would suit a much larger pet, like a big dog.
Bullseye seemed to be content to wear the vest when she was being cuddled and given full access to a human lap. Here I’m checking to see how long her neck strap needed to be to secure the vest. As you can see in the photos above, Bullseye is clearly thinking I’m a big dork for my cat vest plans, and on occasion was wishing I was a bird.
The final vest being modeled on Bullseye, with custom type. Bullseye is very hungry and keeps asking for more food, as displayed by the vest. However her patience soon left her, since we did not give her more food, and she slipped out of the vest and turned her back to it, leaving it abandoned on the floor. Cats. So fickle.