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.

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
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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.