Wrapduino – a wire wrap Arduino clone

I just launched the debut project from my new company, Nerd Creation Lab, on Ingiegogo. I hope you check it out and are able support it.


This project was inspired in part by my late grandfather who was an electrical engineer. I acquired a number of EE items from him including a bunch of wire wrap tools and sockets. This lead me to realize how useful the “dying” art of wire wrap can be. To this end I wanted to make an educational kit to help people learn how to wire wrap. This is more than just a kit, it is a whole educational program. There will be skill badges, wire wrap comics, and kits. I am also planing several instructional videos and online tutorials.

Why ANOTHER Arduino clone?

After much thought about what kind of kit to make I settled on an Arduino clone because the design is fairly simple yet very versatile. The design is very barebones, with no USB and no advanced power management or 3.3v supply. The goal of this kit is to be educational and decorative first, and to be a Arduino clone second.

What We Need & What You Get

The money raised is to leverage volume buys and insure that prices are low enough to enable a wide range of people to learn from these materials.

The rewards are:

Skill badge – 1.7″ diameter round embroidered patch

Comic – 20 page “Wire Wrap is Still Useful and Soldering is Easy” comic book

Basic kit – PCB, Components, Standoffs, and Acrylic base plate

Deluxe Kit – Basic Kit + wire wrap tool

Super Deluxe Kit – Deluxe Kit + Comic and Badge

Super Deluxe Kit with FTDI – Super Deluxe Kit + FTDI adapter

Advertiser special – Super Deluxe Kit + a 2.9in x 2.9in inside front cover ad in the comic

Hackerspace specials

The Impact

This project helps preserve a dying skill and teach people new skills. It is more than just a kit, it is also an educational experience and a beautiful completed project. It is a great conversation starter and gives you a certain nerd cred to have made a wire wrap kit.

This is my second major project, the first was the InkShield. This is also the beginning of a more substantial effort with nerdy projects as I am launching a new site called NerdCreationLab.com which will have more educational kits in the near future. It will also have many resources for Makers, Hackers, and Nerds of all kinds.

EL wire graduation dress

Close-up of EL wire

My sister wanted me to make her graduation dress. When talking about it I asked if she would like it to light up. After the initial “How would that work?” question and looking at pictures of EL wire she loved the idea. I proceeded to buy some samples of EL wire and tape from Adafruit to determine how exactly we would do it and what the design would be. We finally settled on a five color Celtic knot design using EL wire that would match a wrist tattoo she wanted to get. The next step was a trip to Metrix Create: Space to look at EL wire colors. From there we settled on green, red, blue, orange, and purple. We looked in to ordering EL wire from a local distributor but do to cost and simplicity of having ends already on the wires we went with Sparkfun. Initially the intent was to put the wire directly in the dress but later we decided that it would be better to make a separate “belt” with the wires.


Dress lit up (front)



In the end I had to redo one of the end splices and learned that they are actually very easy to do, especially when following the excellent tutorial at Adafruit.

The Textspresso machine

I recently received an email from Kelsey at ZipWhip describing their recent project the Textspresso machine. This is using one of my InkShields and an ink head loaded with edible ink.

It’s a cleaned refilled head. We got our edible inks from inkedibles.com. From there we cut off the top of a standard ink cartridge, swapped the real ink with edible ink, glued the thing back together, and called it good.

In order to combine our cloud texting service with Seattle’s technology and coffee cultures, we created a machine that sends and receives text messages while simultaneously making a coffee. You heard right. We’ve got a robotic barista in the house. Did we mention there’s also a warming plate to keep your coffee warm? Once that feature was completed we decided to take things to the next level. We added an edible ink jet printer that provided a truly over the top touch. The build was completed with lots of head-scratching and weekend work. It was worth it.

They say that they are not selling the machine but that everything will released with an open license soon. I look forward to seeing the source and how others are able to continue to build on it in the future. I am glad people are continuing to find interesting ways to use my InkShield which can bought in my store.

If you know of any other projects that use an InkShield please contact me so I can share them as well.

A “real-life” InkShield project request

I recently had someone contact me requesting some assistance with a project:

Would you or one of your customers be interested in selling an assembled tested kit with the following customization?

My son-in-law is a butcher, and that means wrapping a lot of meat in a white paper wrap commonly referred to as butcher paper. For years and years and years, they have used a machine that prints directly to the paper as it is pulled off the roll. Different engraved wheels may print the stores name, the type meat, cooking instructions… I believe they currently have about 20 different print wheels.

These things do wear out, and apparently there is no one to work on them any more, nor is there a good replacement. Most other people have gone to ordering or printing their own adhesive labels. My son-in-law and his family prefer the print directly to paper, on demand method better, so they asked me if I could “invent” something. I was thinking that the InkShield might be the perfect fit. Of course there are a lot of other design and safety issues to work out, but I thought if someone else was interested in building a working print head as a proof of concept, I could work on the other aspects.

The main problem statement is: “Simple loading and storing of up to 32 text strings of up to 32 characters each. A method of selecting and displaying which of the 32 will be selected. An input that would enable the printing of the selected string, after a second input begins pulsing. The pulse rate determines the speed of the printing. There would need to be a programmable delay of so many pulses before the printing starts. And a second value for delays between repeats of printing the same string.”

I wouldn’t expect any one to work on it for free, but I don’t think we could afford paying consulting engineers rates either. Looking for more of a hobbyist who wanted to prove to his or her spouse, the hobby is not a sink hole. While I could certainly do it myself. I’d prefer to spend my time on other aspects of this family project.


I don’t have time at the moment to work on this particular project but I thought I would post this to see if anyone is interested in working on this project and making some hobby money. If anyone is interested you can contact me via my contact page and I will connect you with Bud to discuss the details.

Solder fume filter

As I have been doing more electronics projects I felt I needed a filter for the solder fumes. Aster some online research into DIY filters I came up with a prototype using a 80x25mm PC fan and some HAPF60 filter taped together.
Masking taped prototype

This worked well, however it was not easy to position and the fan blades were unprotected and I broke one fan by hitting the blade with the tip of my iron. This lead me to design an improved version using a flexible light base and 3D printed parts instead of tape.
Flex light tear down
Complete filter fan
Complete filter fan

This design is very nice and works well. The flexible base allows me to position the fan right above whatever I am soldering. I have released the files for this on Thingiverse.

LCD/SD card backpack

LCD/SD card backpack

I still had some parts in my breadboards from a prior project and was hesitant to take apart the SD card and LCD display portion. These two things are very useful items to have easy access to and both can be complex to setup.

Old breadboard setup

I looked at buying a “proper” SD card breakout that includes the voltage conversion, but I already had the simple breakout PCB and level conversion IC so I thought I should just make one. I also looked at the i2c/SPI character LCD backpack from Adafruit but I had just bought a 20×4 RGB LCD and that board will not support driving the green and blue LEDs. This lead me to design my own board that combines the two with the SD card under the screen. I decided that I wanted the SPI for the LCD as well as access to the original LCD pins.

LCD/SD Schematic

After I did some initial layout I decided it would be fun to use some wire wrap parts that I got from my grandfather, a retired electrical engineer. This allowed me to use my current SD breakout by just wire wrapping to the pin header.

Electric wire wrap tool

This is only the second time I have ever used wire wrap, the first time was a simple ribbon-DIP adapter. As such I did some research into proper wire wrap technique and found a nice high level manual from NASA and a MIL spec, MIL-STD-1130, with excellent detail.

Bottom view

I initially forgot to put a jumper to select either the SPI or the normal LCD pins. I had to add a jumper and pull-up resistor at the end (it is not shown on the schematic here). The final features are:
SD card:

  • 3.3v supply and level conversion
  • Access to write protect and card detect pins

LCD Screen:

  • SPI interface OR Standard LCD pins (RS, E, DB4, DB5, DB6, DB7) (jumper selectable)
  • SPI controlled backlight OR RGB backlight support (jumper selectable)

The last thing to do is 3D print an enclosure to protect the wire wrap. Once I get my printers working again I will print one and post an update.

More photos on flickr
Continue reading

Accessible website design

I have done a lot of research last night and today about assistive technology, braille displays, and screen readers. I found that a very important part of making technology accessible is insuring that everyone can access your information. I know this seems obvious, however there are several parts that are a little tricky.

First I found a site that will do a color blind analysis of your webpage. This will allow you to check that your color scheme works for people with color blindness and that if people have special settings in their web browser to override website colors your site plays well with them. I am proud to say my site currently passes these tests and am including information about it in my site footer.

The other area is how your site appears in text only browsers. This directly affects screen readers and the ability to read your site via voice synthesis or Braille displays. The Web Content Accessibility Guidelines (WCAG) outline this as well as general accessibility requirements.

WCAG 2.0 Quick Reference List
1.1 Text Alternatives: Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.
1.2 Time-based Media: Provide alternatives for time-based media.
1.3 Adaptable: Create content that can be presented in different ways (for example simpler layout) without losing information or structure.
1.4 Distinguishable: Make it easier for users to see and hear content including separating foreground from background.
2.1 Keyboard Accessible: Make all functionality available from a keyboard.
2.2 Enough Time: Provide users enough time to read and use content.
2.3 Seizures: Do not design content in a way that is known to cause seizures.
2.4 Navigable: Provide ways to help users navigate, find content, and determine where they are.
3.1 Readable: Make text content readable and understandable.
3.2 Predictable: Make Web pages appear and operate in predictable ways.
3.3 Input Assistance: Help users avoid and correct mistakes.
4.1 Compatible: Maximize compatibility with current and future user agents, including assistive technologies.
Conformance Requirements

One tool to help evaluate your sites accessibility is a text-only browser, such as lynx. Here is a picture of this page as seen in lynx.

This page viewed in lynx text-based web browser

The initial tests of my site look good but I plan to insure I can meet as many of the WCAG requirements as I can and encourage others to do so as well. I think the first step to insuring equal access to information is to insure we have formatted our information in the most useful way, not just visually.

Open Source Assistive Technology

I was inspired by a discussion about Stephen Hawking’s recent job posting on Adafruit’s New Years Eve Ask an Engineer show. So I made an Open Source Assistive Technology wiki with the goal of having a place to discuss and develop open source hardware solutions for various disabilities.

These include:

  • speech synthesis
  • braille displays
  • alternative keyboards
  • alternative mice
  • etc…

Currently the site is very sparse, but I hope others will find it a useful place to connect and share needs and solutions.

Fiber-optic Christmas tree RGB LED upgrade


Just before Christmas my mother asked me about fixing an old fiber-optic Christmas tree that she had. I opened it up to discover that the color wheel had already been replaced with a mirror, a 12v 20W halogen, and a non-original color wheel.

It was also evident that it had been hot enough in the past to partially melt the housing.

I told her that I could probably not fix it for this year but after Christmas I would look at upgrading it to LEDs. I then proceeded to research a simple RGB LED driver circuit. I settled on an ATtiny13 and some transistors I had laying around. I found several example circuits and firmware, todbot and unixbigot. Both of these are very similar, however my final design is based on the second and uses his firmware.


Once I had a prototype on a breadboard I decided to do a quick layout in Kicad to help position the components on the perfboard. I then used a 1:1 printout to mark the locations of the components.


To power the project I wanted to use the existing barrel jack connector since it already fit in the housing.


This worked well as common 5.5mm x 2.1mm plugs fit. The next problem was that I lost the 7805 chips that I had, so I tried using a LM317 this worked however it gets very hot. So I ordered some new 7805 chips and wired that up to regulate the wall adapter to 5v.



There are more pictures here

Continue reading

An InkShield ticker-tape machine

While I was making the InkShield I thought of a very interesting project that it would be perfect for, a ticker-tape style printer. The reason this is so nice is that a ticker-tape machine has a fixed head and only one axis. This makes for a very simple design.

I thought about several ways of doing this and finally settled on a serial printer design with a Processing.org “driver” on the PC side. The advantages of this approach are that I did not need a Ethernet shield and I could minimize the font table overhead, ~100 characters @ 24 bytes each = 2400 bytes, on the Arduino. The other advantage is that the printer does not care what it is printing and you can send arbitrary 12 pixel high “bitmaps”.

I am using a Darlington array to drive the unipolar stepper motor as shown here.

The current PC side software accesses Twitter and reads tweets containing “#tickertest”, if it finds one it sends it to the printer and then searches again. If it finds a new tweet it prints that as well and repeats the search.




Once I clean-up the code a little bit I will share it on github.

I will try to get a decent video of it in action and post that soon as well.