Introduction: Radioactive Raspberry Pi Drawstring Bag Backpack
Ironically, powered by an Adafruit Flora arduino, ok, whatever silicon chip wafers are made of.
Make this wearable light up emblem of the Raspberry Pi built into this cool handy drawstring bag that also doubles as a backpack. How awesome is that?
If you don't need something with as much processing power, go with this 555 timer chip backpack. https://www.instructables.com/id/Giant-555-Timer-C...
It's not really radioactive as much as it's just a glowing berry. Magically delicious neopixel LEDs light up the emblem.
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Step 1: Solder, Wait, Sewing Mask...
This is half sewing, half electronics
When the raspberry pi first came out, there was a promotional backpack that resembled a raspberry. It was all 3D-like and bumpy to resemble the texture of a real raspberry. I don't have that technique of forming the 3D panels down yet but I will attempt to create something similar maybe by poufing out the parts of the raspberry emblem with fiberfill stuffing. It will also help to diffuse the neopixels to even out the lighting.
I am going to rush through the build but learn to sew and learn to solder, both essential skills to have.
I used some microfleece for the bag but you can use some sturdier ripstop nylon or canvas. It is red for the base color. The finished bag is about 12 x 18 so cut front and back panels slightly larger for seam allowance. You can make it bigger if needed to accommodate a looseleaf binder or something.
I used a piece of black felt for the raspberry outline.
I also had a small piece of light green felt to use for the leaves.
Find an image of the Raspberry Pi logo. Print it out as your cutting pattern. I sized it up to full page size but you can make it any size needed. It is their trademark so due respect.
Cut out the cutouts. Sew or glue onto the fabric panel for the front of the bag. I used a zigzag stitch to applique the black raspberry outline. Since the leaves are a different color, I sewed in the different color felt and cut away the red microfleece under so that the light shines through that fabric portion unfiltered.
I tried to expand the cutout sections by pushing from behind and shaping. The microfleece does not have too much give as would a knit fabric. I would have then filled cutout sections with fiberfill to make a better 3D effect..
Cover the back of the emblem with a piece of fiberfill sheet batting. Sew another layer of fabric to cover and form a pocket to hold your neopixel strip or discrete LEDs.
Step 2: a Light Bulb Just Went Off...
You can use any type of LEDs to light up the back of the raspberry. You could probably tackle this with battery powered Christmas lights if that is all you have.
I am using the same setup I had from my thermometer scarf which evolved into the high striker scarf.
It is an Adafruit Flora wearable arduino with a neopixel strip and neopixel ring attached. If you look closely, it still has the DIYswitch pad hanging off of it and a new Adafruit Bluefruit bluetooth module which I am playing around with to remotely change the color of the lights with an app on a tablet.
The sketch that is on there is essentially just doing a rainbow color theatre chase light animation.
One lesson you can take away while making wearables with light is how physical filters affect light. These neopixel LEDs are outputtting RGB - red, green, and blue. The fabric looks brightest when transmitting its own color. I would have to use real light filtering fabrics if I wanted to use a pure white light neopixel.
If you were using a Raspberry Pi to do the lighting, you would need Adafruit Dotstar addressable LEDs.
The neopixel strip and neopixel ring are stuffed behind the fiberfill batting. The rest of the electronics are tucked into a hanging pocket.
Step 3: String Theory to Bring Closure...
You can use cord or rope to make the drawstring closing device and to act as the straps. Have two drawstrings about 6 feet long. I used some glow-in-the-dark rope which would look nice glowing in the dark. Bonus safety points too.
You can even make a set of color coordinated drawstrings by sewing a strip of fabric.
Sew a channel or hem both sides of the top of the bag. Leave openings at each side so that you can pull the drawstring though.
Sew the two sides and the bottom together to form the bag. Flip inside out to get finished edges.
At the bottom corners, make a buttonhole or install grommets for the cord to attach to. You can reinforce the two bottom corners of the bag with an extra piece of fabric.
In the top channel, feed one cord through one side and come back through the other side. Attach a safety pin or tape up the end of the cord to make it easier to feed and fish through the channel.
Tie off both ends of the drawstring to the bottom corner grommet.
Do the same with the second drawstring cord starting on the other side. Have it loop around and tie off at the bottom corner grommet.
Pull both drawstrings to close off the top of the bag.
Now put your geek on and rock the radioactive raspberry.