Intro: Wearable Breadboard for Electronics - ProtoHoodie
When you prototype, what else do you do but use a prototype? From circuit designer to fashion designer, this wearable breadboard does it all. Components optional.
Breadboards for electronics (no, I never asked why they are named that), are useful platforms to physically experiment with electronic components in connecting them in circuits. The components such as resistors, capacitors, integrated circuits, etc. can be plugged into the breadboard according to a circuit design and can easily be modified by moving, adding or removing the parts or short pieces of wire called jumpers. Underneath the breadboard grid is a series of rails to simpify the wire connections. A power supply can be connected to the breadboard to supply power for the circuit.
Inspiration for this project was from having met Instructables member Stasterisk at the World Maker Faire NYC 2010. It was a nice surprise that she recognized us out of the crowd. Maybe because Caitlin and I were both wearing our Robot shirts. It was the first of many encounters throughout the day..."You're Caitlin....and you must be....." Yeah, I get that all the time. Anyway, I had dragged Caitlin to the Maker Faire where everyone was a total stranger, she does know of Goodhart though *sigh*. When we got home, she went online to find out about who we met. Then she read up on Star and her breadboard sweatshirt. Caitlin said "Don't those @#$%^&*! know it's Art?" That was the highlight of her Maker Faire. "Cool!"
So, also having met Lynne Bruning at the Maker Faire and bribing Caitlin to model the Blinking Hand of Righteousness and the blinking i-Hoodie at her e-textile Fashion show, that got me inspired to do my take on wearable electronics. And look, there is a soft circuit contest going on!
I do not have an arduino or any of its variants/offspring. Still a little pricey to get set up.
I do not have any conductive thread. I have this spool of decorative metallic thread from Walmart, but I suspect it isn't the same quality of pricey conductive thread. It was pretty rough running it through the sewing machine when I embroided Caitlin's homemade dentist coat way back when I made the giant toothbrush. The real stuff may be neat to work with but it still has high resistance and still not what I consider mil-spec. It is not weatherproof or spillproof and it is not insulated.
I've got a few more tricks to do with the dollar store bicycle flasher but I wanted something new.
Behold, the Wearable Breadboard of Righteousness. Prototype circuits on the go. Well, maybe not near public transport.
Step 1: Stuff to Scavenge
I got a roll shelf liner made from real cork. It has adhesive on the back and is thin enough to be flexible. You might be able to use some that is sold as sheets to line bulletin boards but may be too thick and rigid that it would crack if bent.
Three layers of the cork shelf liner adds up to 1/8th inch thick, enough to pierce and hold the component lead.
Electronic components to use on the breadboard.
I had a battery holder, some LEDs and corresponding resistors.
Search LED calculator on the internet to find a quick tool to figure out the resistor values for your LEDs so they don't burn out prematurely.
Plastic Grid for Needlecraft
Not really sure what this stuff is called but you find it at the craft store to use as a base for making yarn carpets or designs.
Aluminum duct repair tape
The heavy duty waterproof kind has a thicker metal layer...and a stickier industrial mastic adhesive layer.
Check connectivity and voltage in order to troubleshoot the circuit
metal two-part snaps or pin/receiver design to use as connectors
Silicone putty - still trying to find some neato applications for it. I used it to coat the battery plugs or probe ends.
Velcro, duct tape. glue or thread and needle to attach wearable breadboard to garments.
Hoodie or other garment
Garment to attach the breadboard to.
Various other electronics working tools
wire stripper, soldering iron, pliers, scissors...
CAUTION: I soldered a few wires. Know how to operate a soldering iron responsibly. A soldering iron can burn and solder contains lead which will soon be outlawed in the State of California.
Step 2: Prep the Base Layers
I randomly picked a nice size for my wearable breadboard. 6x4 inches. It looked the right size for a patch.
Cut out three pieces of the cork shelf liner. I think 2 layers would have worked also. The more layers, the stiffer it gets.
Cut out a corresponding piece of the plastic mesh to use as the grid look top layer.
From the aluminum duct repair tape, cut out strips that will be the conducting traces under the grid. Mine were about 3/8ths inch wide.
Peel the backing paper away from the cork pieces.
Laminate together leaving the adhesive side up. This will be your working surface to attach the traces and the covering grid.
Laminating the pieces helps take out the curl from the roll.
Stop here and stick it to your hoodie if you just want a wearable bulletin board system
Step 3: Trace It Out
When cutting this aluminum duct repair tape, sticky adhesive gunk will build up on your scissors. Wipe off with some rubbing alcohol solution to clean them, I found it easier to tack down one end of the strip and cut to size on the board.
Breadboards usually have some buss strips so you can run power the length of the board.
Lay down two strips on each side if you have room.
For the infield, lay some strips perpendicular to the buss strips. You can segment them to give you more connection pads and flexibility in your circuit design. I could just fit two.
If I were to make this again, I would double layer each of the metal strips. I might even embed a wire or two under each of the strips, maybe some desoldering wick.
In actual use, the component lead punches through the aluminum foil layer and sticks in the cork layer. I think oxidation on the aluminum foil, the lead getting coated with adhesive and widening the puncture point leads to an unreliable contact. A lot of time was spent wiggling the wires and testing with the multimeter to see where the contact was bad.
Once you are satisfied with placing on enough metal traces, slap on the mesh top layer.
Use a sharpie to put the blue and red lines to denote the power buss.
That's all there is to the wearable breadboard, really.
Step 4: Scotty, I Need More Power...
Real geeks wear their power source on the outside. Just look at the pair of rechargeable NimH AAA batteries I've got hanging... Just be careful when they prematurely discharge.
So this is a double AAA battery holder case It will give me 3 volts (2 x 1.5v) to power the LEDs.
I punched some starter holes and fed tie-wraps through to secure the battery pack to the breadboard.
For the ends of the battery pack I was going to make some cool plug-in connectors.
I used just the male snap part and soldered the wire I had fed through the holes.
In retrospect, these did not work very well because it did not fit as tightly in the grid and did not really puncture the foil to make good contact. The blob of solder on the face through the hole probably kept it from getting seated deeply in the grid.
Maybe if I sewed the corresponding female snap on the breadboard with conductive thread or mounted with more aluminum tape, it may have worked better.
I soldered some snaps to the ends of leads on a momentary push button switch I had.
I used a pack of Sugru, the miracle silicone wonder putty to insulate the solder joints and to give it a handle. You really need to wait overnight for the Sugru to really adhere. I kept on messing with the red lead from the battery pack so that Sugru blob pulled away.
The switch turned out like some electronic parts gumby, dangit.
I did roll the uncured Sugru against the mesh grid. It kind of gave it that green Army soldier frag grenade look. Hmmm.
Step 5: Apply Yourself
Add the cool tiny Robot sticker to the battery case.
So get out your electronics parts and start prototyping.
Jam in the power connectors to bring the grid up.
Hold the ends of your leads close to the end so you can prick the foil layer and insert the electronic component.
Here I have demonstrated lighting up two LEDs in parallel with resistors.
The board does flex and components are not 100% secure if you violently shake it. Making the mods mentioned before will help with reliability.
I had an assortment pack of LEDs so I had to guess at what they were rated as and came out with an even lamer value for the resistor using an online LED calculator. Lucky I didn't look too close when I bought some resistor packs at Radidio Shack. I had 100k and 100 ohms. The 100 ohms worked.
I cut and stripped the ends of some jumper wires to use in the breadboard.
From this you can learn basic circuits. Add more components such as motors, more lights, readouts, transistors, capacitors, resistors, etc. Plug and play. Know which end of the LED goes to hot.
Attach to your favorite hoodie and always have a breadboard handy to prototype.
Somebody do a stop motion prototyping session a la LEGO man.
Anyone want a wearable Arp 2600 or Moog Modular?
This was an experiment in experimenting. Have fun making one.