About: I'm a digital artist/crafter/maker who likes electronics and sewing. I used to run the blog Soft Circuit Saturdays, which is now part of my site GellaCraft - dedicated to techy crafts, costuming, and art.

Create your own screen accurate Hello Unicorn backpack from Altered Carbon that automatically lights up when you unzip and open it. Ever since I first watched the show I've been obsessed with this backpack, so I built one to bring to Denver Comic Con. I even found a Takeshi Kovacs cosplayer to model it for me! I also use it when I teach workshops on costume tech as an example of incorporating electronics into cosplay prop builds.

Don't know what the Hello Unicorn backpack is? Check out this reference: a video with lots of Hello Unicorn moments from the official Altered Carbon Facebook page.

How Does It Work?

The interior is lined with addressable LEDs set to a blueish hue (matching the show) that turn on when the backpack is open and turn off when it is closed again. The trigger mechanism is a small magnet and reed switch placed on either side of to center of the backpack that connect to an Arduino microcontroller.

Skills Needed:

You'll need some basic soldering, painting, and sewing skills to complete the project and basic experience uploading code and installing libraries in Arduino.

Electronics Needed:

SparkFun Pro Micro 5Vor equivalent microcontroller with micro USB connector

~2.25 meters of NeoPixel LED strips, I used these(you can sub a single color/non-addressable strand to save money or if you don't care about the blue hue matching the show exactly)

Electrolytic capacitor - 1000uF/25V (optional, but helps with performance)

USB power bank, I used this slim 5Ah lithium ion battery pack

Micro USB cable (if not included with the power bank)

Insulated reed switchthe plastic casing is more durable

~3-4 ft of stranded hookup wire (ribbon cable works great for this)

Soldering iron and solder

Heatshrink

I made a wishlist on SparkFun.com with most of the parts I used for this build (excluding soldering tools). Feel free to swap any of the parts in this list with compatible parts as needed for price and sourcing considerations.

Non-Electronic Parts/Tools:

Pink hard shell backpack (I found one on Amazon with construction very similar to the one used in the show)

Spray paint - white primer and pink slightly darker than the fabric of the backpack bring print outs with you to the store to find the perfect color

Paint brushes large and small for fine detail

Acrylic paints in red, yellow, orange, green, light blue/teal, dark blue, purple, light purple, white, and black

Spray acrylic clear coat/sealer

Masking tape

Vinyl cutter and vinyl I used a Silhouette Cameo and 12x12 vinyl sheet

Permanent marker and pencil

Clear vinyl (I used less than 1/2 yard)

Clear or pink thread and needle

Exacto knife and/or small scissors

Hot glue gun

Velcro

Pink fabric to match interior of backpack

Thick black webbing (if you'd like to attach to the top of the backpack for screen accuracy)

Small magnet (rare earth magnet works best)

Sewing machine (optional)

Small plastic bags (optional, for 'drugs' to fill the bag with)

Addipak 3ml unit dose containers, wax stick candy, or mini glow sticks (optional, for 'drugs' to fill the bag with)

Software Needed: