Step 1: Ampli-tie This, Ampli-tie That...
This is another project that I did as I went along. And this is how it went...
Most things trace back to the Adafruit Ampli-tie project. You can make a sound-reactive device lighting up Neopixel LEDs. It was the first big thing that inspired me to go get my first wearable Arduino board and a bunch of Neopixels. It was easy to configure, wire up, program and put the blinky bling on tons of stuff. And the rest is random...history.
Technology changes so fast in a short time. The boards on the market today make it so easy to get started in merging technology with my other passion, Art, ok, one of my other passions...
New, new, new... Mu, Mu, Mu...
So what I have to experiment now is an Adafruit Circuit Playground Express board. It runs the new Circuit Python code and am using the Mu Editor to make program changes and develop in real time.
I was happy when the example for the Circuit Python version of Ampli-tie came out. The Sound Meter code for the Circuit Playground Express board allowed me to start "porting" things over to the Circuit Playground Express board (CPX). I had recently fried one of my old Flora boards, and the onboard sensors on the CPX are more than convenient.
I knew I could add more Neopixels to be driven by the CPX. Using the Mu editor to splice in new code for the added Neopixels to the Sound Meter code, I knew immediately that things were not working as I expected. The latest Mu version has a built in syntax checker to detect any errors my code had. But more importantly, when it ran in the serial/REPL I noticed that the lights did not light the way I wanted it to. The lighting of the added neopixels put in a slight delay that was noticeable in how the sound reactive lights behaved. The quick edit/upload/run cycle using Mu let me experiment with placing the new code in different parts of the loop to minimize the impact it had. I still have to go back and try to speed it up or optimize the code somehow. Mu was also great to see the "serial monitor" output to tweak the sound sampling parameters in code to adjust the microphone sensor input.
Step 2: O Noe-kun!
I dunno, maybe it started from an idea from Custom Light Up Monsters.
What else can we do with the Roe-kun character? And here we are.
Find some clipart to start with and print it out.
You could also create your own cutting templates by sketching it out on your own if desired.
I also saw something that was fittingly Pedro-kun.
Noe and Pedro Ruiz are Adafruit's 3D printing experts and have their weekly webshow 3D Hangouts.
You can watch them do layer by layer on 3D Printing or papercraft design and cutting.
I cut out pieces of felt to glue together for my patch figures.
Step 3: Time to Bag Things Up...
I have a Neopixel stick added to the Circuit Playground Express board. I can use the Neopixels on the board to light up the mouth part and the externally wired stick to light up another part. I programmed the stick to flash red or blue and the board Neopixels would light up in a rainbow of colors depending on the intensity of the sound it picks up from the onboard microphone. I wrapped the board and the stick with a bit of fiberfill batting to diffuse the Neopixels to produce a better glow.
The bag or sack is simple to make.
I used a shipping envelope I had nearby to size the bag. You could use your laptop, school looseleaf binder or books to gauge what you will carry in the backpack. Cut two pieces(a front and back) or double layer of fabric with a few inches extra on each side to give it sewing allowance and material where we will make the conduit for the drawstrings.
The patch figures did not stand out on the black fabric that I had to make the bag so I glued on an extra layer of felt to be the background or highlighter border. Do not glue where you want an opening to stuff in the electronics later.
When the glue has dried, trim around the patch figure. I guess Noe-kun got the action-hero B A M !!! exploding jagged edge border. There's probably some name for that superhero aura effect.
Step 4: Don't Trip Over the Laces...
Sew your patch figures to the front of the bag. I used an applique-like zigzag stitch.
Now we will be working with the bag inside out so you get nice finished seams on the outside.
I have a serger so it was easy to sew, trim and bind a seam in one pass. You could also just use a straight stitch with a regular sewing machine.
Seam off both sides of your bag. My fabric was folded over so I just had to seam one side.
Seam off the bottom of the bag. I seamed off the bottom corners of the bag.
There are a lot of ways to create the channel that the drawstrings run in at the top of the bag.
You could treat it like hemming up a garment.
I first clipped off the two top corners at an angle to match what I did on the bottom
I then finished off that edge by going all around with the serger.
I then folded over the flap on each side and sewed the bottom edge leaving the ends open. That creates a tunnel for the drawstring to run in.
I cut my drawstrings from paracord. Cut a doubled length that runs along the top and a side of the bag.
With paracord or other synthetic material ropes/cord, I like to seal the ends to keep them from unravelling. I went to go roast the ends on my gas stovetop. Only do that if you are a pro and it is your kitchen...and you own it...and insurance is paid up.
Attach a safety pin to one end of the cord. It will help you feed it through the fabric tunnel. It should go in one side, loop around into the other side and back out. Do the same thing from the opposite side with the other piece of cord. When you pull on both sets of drawstrings, the bag opening should close up.
Take a look at the Neopixel Flaming Poop Emoji Bag for more drawstring bag construction.
Step 5: Wiring It Up...
You can sew tabs or add a cloth loop to tie off the ends of the drawstrings.
I had a grommet kit so I will put in a grommet at the bottom corner of the bag. These are metal grommets and essentially work just like a rivet. You punch a hole to get the grommet head with the a tube like part through the fabric layers. Put a washer or backing plate on the back. Sandwich the anvil die pieces over the top and bottom of the grommet assembly. Hammer away till the metal inner part flares out against the backing plate to secure everything together and is smooth to touch.
I decided to put in a few more grommets and label them with dimensional fabric paint.
I made some Jumper Cable Clip end covers for the drawstrings. I used aluminum foil duct tape to cover small cardboard pieces. I sewed a simple insulation cover boot. Feed the drawstrings through the cloth boot. Tape the metal foil covered pieces over the drawstrings Pull the boot down over the assembly. You can take needlenose pliers to further shape the jaws of the jumper clip.
Now for each side, you can pass the ends of the drawstrings through the bottom grommet. Tie a big double knot so it can't pull through. You can now test out the bag closing and wearing as a backpack.
Step 6: Power It Up and Take It for a Spin...
Since my Neopixel stick was wired up to the Circuit Playground Express board with connectors in the line, I was able to break the connection in the cable. It makes it easier to route your wires when you embed the electronics. I punched some holes to pass the Neopixel stick and wiring through in order to mount the stick in position. The battery pack and board were stuffed in the main part of the patch figure.
Now go out and make anything you want and have fun with it!