Monday, 9 November 2015

Kids Zelda costumes

Young Link, Sheik, and Fire Temple Link
(from Ocarina of Time)

I made the swords from foam swords bought at the pound shop, the tunics and hats from dyed cotton polo-shirts, the tabard and wrappings from a stiff cotton from my stash, and the leggings and sleeves from a pair of running trousers. The shields and harp are hand-painted onto kitchen chair cushions.

Thanks to Barry Kelly for the photo (from Octocon).

Sunday, 11 October 2015

Octocon 2015

We had a wonderful time at Octocon. Thanks to everyone who called to the stand. I'd love to see any photos you have of your bracelets and completed embroidery kits!

Here's a close-up of my favourite colour combination from the weekend

I'm happy to take bracelet orders by email or comments here on the blog.

I'll be developing more cross-stitch kits too, so I'm looking for suggestions of any favourite 8-bit imagery you'd like to stitch a picture of.

I'll link to photos of the kids costumes as soon as I get my hands on them.

edited to add:

Here's a photo of my favourite phrase from the weekend - "There are four lights!"

Sunday, 4 October 2015

The best way to make toy shields

The kids are dressing up with a Zelda theme for halloween this year, but the costumes need to be ready for Octocon next weekend. After searching high and low for toy shields that I could modify for their costumes I came up with one of my best ideas ever: cushion shields.

I bought flat kitchen-chair cushions, moved the ties onto the back

and painted the front

They're soft, light, and hold their shape. Perfect!

I'm really proud of the painting, so I'm very reluctant to actually hand them over to the kids, but they'll get them soon :)

Sunday, 26 July 2015

Core Rope Memory - the story so far

This is an overview of the demo of Core Rope Memory as we presented it at yesterday's Dublin Maker. There are already design improvements in the planning stage so watch this tag.

Here's a photo of how the demo currently looks:

The green donut shaped magnets, and the red wires (let's call them rope-wires) woven through and around them, are the Core Rope Memory. Everything else you see is equipment for reading the values from it. If you take that piece of balsa wood out of all the other circuitry, it still contains the same data, because it is the weaving of the wires that stores data into the memory.

At the top left, plugged into the battery, is the pulse generator. This is a circuit based on the 555 timer chip that generates a square wave. The red wire coming from that circuit is a probe that can send that pulse through the horizontal wires in the memory, one at a time.

Each of the green cores has another wire (let's call it the core-wire) wrapped around it several times. Because of an effect called electromagnetic induction, we can induce a current in the core-wires. If a rope-wire goes through a particular core, and we send a pulse through it, a current starts to flow through that core-wire. If the rope-wire goes around the core, no current is induced. We can interpret this as 1 (where a current is induced) and 0 (where no current is induced). That means that we can encode a binary string for each rope-wire. That binary string's length with be equal to the number of cores. The wires in the photos encode T (10100), I (01001), M (01101), U (10101), I (01001).

When the Arduino senses new values in the core-wires, it interprets them according to a sort of truncated ASCII, and displays the character on the LED display. I knew I only wanted to display capital letters, and I had reasons for using 5 bits, so I pre-pended 010 to the values read from the memory, and display the resulting ASCII character.

It's a pity I had to include a multiplexer in this demo, because it makes it look more complicated than it is (I had simply run out of analog pins on the Arduino), but I'll be able to use it in future versions of the demo.

Thanks again to everyone who made Dublin Maker 2015 possible, and special thanks to the author of this Core Rope Memory tutorial.

Dublin Maker 2015

Wow! What a brilliant day. We got lovely weather, and so many enthusiastic and interested visitors.

Thanks to everyone who came to the stand. I hope you had as much fun as we did. Thanks to Cian and Róisín for all your hard work, and to the whole team who made Dublin Maker happen.

(I was too busy all day to take any more photos, but there are a couple here:
and here:

Sunday, 19 July 2015

Demo photos

Here's what the main demo for Dublin Maker looks like:

I'm *really* happy with how it looks. The piece of memory is not fixed to the board, because I'm still hoping I'll get another piece made in time and I want to be able to swap it into the reading equipment. The second piece of memory will be modifiable by visitors, so they can encode a message and then see it printed to the display.

These are large wooden mockups of Core Rope Memory that illustrate the difference my Pretty Bits encoding makes. They both encode the same phrase "One small step", but the top one is 7-bit ASCII, while the lower one is Pretty Bits. I think it really shows the value of a custom encoding. It also pointed out to me that capital 'O' is currently encoded as all zeroes, which I think I'll fix in a future version.

Next step, a little more hot-gluing to make modifiable wooden mockups for visitors to try, and then hopefully the functional modifiable memory.

I also have to prepare my 5 minute talk for the day. Thanks to Róisín for the title "One small step and a bit".

Friday, 10 July 2015


It's working!

I haven't posted progress shots in a couple of days, because my camera was a bit borked, but I put the effort into fixing it, because I have a working piece of Core Rope Memory that reads to my quad alphanumeric display!!!!

My camera would only record a few seconds, so it took three little videos to show me reading the 5 characters of TIMUI with my little probe. There's a lot of work to do on tidying up the code, and getting posters and things ready for the day, but I should at least have something to show!

I've never included a video in a blog post before, so I don't know if this is going to work well at all. Here's a photo in any case:

I picked a 5 letter word, and it's on a 4 character display, so the photo just shows it saying 'IMUI'. Oh well :)

I made Core Rope Memory you guys!

Wednesday, 1 July 2015

Mux prototype

I'm not sure if I mentioned the analog multiplexer I ordered, but it arrived, and I've just tidied away the first prototype using it:

My Arduino doesn't have enough analog pins for my purposes, but this little breakout board solves the problem nicely.

I'm looking forward to getting some more things soldered down and the final tidy-up done -- though I think the photos are finally starting to show the reduction in visual complexity.

Tuesday, 30 June 2015

So much soldering

I've soldered my 555 pulse generator and my voltage-modifier onto two small pieces of strip board. Here's a couple of photos of the setup for testing the windings on the 5 cores I'll be using for my first full demo.

(the battery isn't in the case, and the arduino is not plugged in because I had started tidying it away before I thought of taking photos).

This one will be a permanent encoding of the word "timui" which visitors to the stand will be able to read with a probe. The next one will be set up for visitors to encode messages into themselves.

Things are really progressing well! I should be back in TOG tomorrow evening and hopefully I can get another 4 of the voltage-modifiers ready to go. It is getting progressively neater, even if that's not obvious from the photos :)

edited to add: I forgot to mention the 9V power supply problem. I was really looking forward to hooking it up and reducing the number of crocodile clips (and amount of fiddling), but when I tested it I realised it was producing 12V. I guess it was mislabeled; that's probably what broke the device it comes from.

Monday, 29 June 2015

One bit on the Quad Alphanum Display

Things have been proceeding very quickly thanks to Gary and Becky's help. I now have one bit being displayed correctly by my Arduino onto my quad alphanumeric display.

One small glitch became apparent this morning though: the quad display uses 2 of the analog inputs on the Arduino and I wanted to have at least 5 bits in my demo. That's 7 analog pins, but my Arduino Uno only has 6. I considered upgrading to an Aduino Mega, but I've ordered an analog multiplexer instead. Hopefully it'll get here quickly. In the meantime I can add up to 3 more bits before I run out of direct analog connections.

I'll be breaking out the soldering iron tonight. I found a 9V power supply that I'd saved from a broken device, so I'll be replacing the battery in the 555 timer circuit with that, and I have to desolder the socket from the board it's on. Then I have to figure out which pin is which. Then I want to fix the 555 timer circuit and my little voltage shifting circuit onto some stripboard; they've been on plug-board way too long, and it's making me nervous :)

It's so much fun to have a tangle of wires an components on the table in front of me and have a good idea of what's going on :)

Friday, 19 June 2015

One bit down!

I brought my growing collection of gear for the electronics side of my Core Rope Memory project back to TOG on Sunday. @tangentmonger arrived just as I was beginning to despair, and between us we got a working bit of memory! Thanks Becky!

The photo above is the pulse generator circuit (with a 555 timer chip at the centre). We made it with a lot of trial and error, and reference to this page

This photo shows the output of the pulse generator passing through the wire-wrapped toroid core. We were able to detect the induced current in the coil when the pulse generator was active.

I'll be heading back in to TOG, so hopefully there'll be more progress to report soon.

Tuesday, 2 June 2015

My first visit to TOG

I finally made it to TOG last Monday evening to work on my demo of Core Rope Memory. It took me a while to get my bearings, but by the end of the evening I had everything I needed to wire up the pulse generator I need to send pulses through the word-lines (thanks so much for the help Gary!). I'd post a photo, but I haven't tested it yet :)

I'm hopeful that by the end of my next visit I should have a working demo, so that's exciting!

Friday, 15 May 2015

Sewing Utility Belt

I threw this together in a hurry, so their are no clean edges, and no progress shots.

I'll be helping Róisín at the dress rehearsal for The Merry Widow tomorrow. After helping out with the fitting on Tuesday I now have a reasonable idea of what I'll want to hand, and just how close I'll want it. Since I couldn't get my hands on the costumes that were plaguing my thoughts I decided to do something that felt like preparation.

The fabric was originally bought for curtains, but then I decided it was too orange, so it's been sitting around in my stash. It's thick enough to feel sturdy though, which makes it perfect for this project. I cut about a quarter metre the full width of the fabric, and then cut that in 3.  I turned down the tops of the front two layers and then sewed them together to make pockets (two snug, and two roomy).

I found an old strap from a backpack in my stash which was perfect for a belt -- nice and broad, and the clip only required slight modification to clip easily around me. I made a channel for it with a cut off from one of the pocket layers. It was the perfect length without modification, and already had the mechanism for lengthening/shortening. Score! 

It even perfectly fits the belt loop of my leatherman case! I felt the lack of a pen-knife on Tuesday evening, so it'll be nice having that on my hip.

A little spare fabric in a loop holds my scissors upright and out of the way, but still safely in a pocket. 

This was a lot of fun to make. It's nice to have a quick project work out so well. It was also kind of fun to just rush through it without caring too much about neatness.

Saturday, 2 May 2015

Quick hit: quarter metre cuddle cushions

Have you ever seen a gorgeous fabric that you couldn't think of a project for? This has happened me many times, and usually I resist the urge to buy it, but this was too cute to leave behind.

I bought a half metre, sure I could come up with *something*.

As Róisín and I sat in the lovely café attached to So Sew in Naas I realised that I could just make a pair of little cuddly cushions.

I considered a few different options, including making half-metre square cushions backed with some other fabric, but in the end I decided that wide and short (as in not tall) cushions would suit the fabric best.

I cut the piece in two, making two quarter-metre strips the full width of the fabric, and sewed the selvages together.

This was ironed flat right-side out with the seam off centre on the back. I used french seams on the top and bottom, with a gap for stuffing. I had planned to have the french seams inside-out to give that classic cushion edge look, but with the first one I was kind of on auto-pilot, and did the first line of stitching wrong sides together (as you would with a hidden french seam). I decided to keep going and do one in each style for comparison.

Gap in stitching for stuffing

Gap ironed under before stuffing, to make later stitching easier

Stuff em!

This is how the stitched closed gap looked on the hidden-french-seam cushion. I guess that's why it's popular to do it backwards.

Comparison shot. I think both versions have their advantages -- I like the roundy look of the seams-inside version, but I also like the way the stuffing-gap is hidden on the seams-outside version.

The kids were both delighted with them, and I don't think they've noticed the difference :)

Tuesday, 28 April 2015

Soldering: not so scary afterall

I'm planning to present a demo of Core Rope Memory at this year's Dublin Maker but there are some skills I need to develop before I can start working directly on that demo. Number 1 on that list is soldering.

I've always found soldering pretty intimidating, which is why I've never tried it before. Turns out it's not that hard! Just over a week ago I put together a silly flashing heart on my first try:

And then the eldest decided she wanted in on the action:

We twisted some copper wires together to give her an easier target than a tiny component, but I think she'll be ready for something more difficult very soon.

There will be two of these in the post as soon as they're back in stock :)

The main reason I wanted to learn to solder, was to put together this puppy:

Which I have now done!

Monday, 27 April 2015

Pretty Bits

As part of my Core Rope Memory project I've devised a binary encoding I call PrettyBits.

Why a new encoding, you ask? Well it turns out that ASCII has certain features that make it a bit ugly when used in my jewellery. Even if I just use 7 beads, (ignoring the leading bit that doesn't get used in basic ASCII), the two leading bits are always one for lower case letters, and there's a bias toward 0 on the lower order bits. I think this leaves the piece messy and unbalanced.

The effect is exaggerated here by the nylon beading string (a failed experiment), but it's also evident in the photo from my previous post:

(Both pieces have most-significant bit on the right in these photos).

Since ASCII was an arbitrary choice of encoding anyway, I started thinking about what I would like in an encoding for this jewellery, and I came up with three things:
1) Minimize zeros - the more threads through beads the neater it will look
2) Minimize strings of zeros - a thread weaving in and out of beads will look better than one going around three bead in a row
3) Balance the zeros between the left half and right half of the piece

I decided to use 7 bits, because having a central bit is nice, and because that gave me room to include lots of punctuation and the Irish accented vowels.

The first thing I did was generate a list of all the bit strings from 0000000 to 1111111. Which I ordered according to the rules above. Then I used the data in 
to produce an approximate frequency ordering including punctuation and capitalisation. The two lists were zipped together, so that the most frequently used characters got the prettiest bit-strings. I used that list to make this webpage work:
(edited to update link)

Here's the first piece made with the new encoding! I'm not very happy with the photo, but I think it just about shows that the new encoding is much more balanced. (I think it's very evident in-person).

This bracelet (no clasp yet) was made with found copper wire, so it's not hypoallergenic. The previous design is the best hypoallergenic solution I've come up with so far, though there are some high-end materials I can try if someone wants to order the wire-style above for sensitive skin.

I'll post soon about the more electronics-y side of this project, including my adventures with soldering and my new Arduino!

Tuesday, 14 April 2015

Homemade Othello board

I'm sort-of amazed that I never posted about this before. We made it almost a year ago:

We couldn't find an Othello set anywhere in Cork, so we decided to make one.

I'm sure I had planned an elaborate post giving all the details, but you'll have to make do with what I can remember :) The 'case' is just a cheap cardboard file which opens up to reveal:

The grid is cotton string glued down with Bostik. We wanted something textured to hold the pieces in place, and this works very well. (The sides need to be weighed down to stay flat, hence the cup).

The boxes for the playing pieces are made from thin card, and they fold up with the pieces inside when the set is being put away.

The pieces are made of circular stickers, stuck to the black card, and then cut out.

Et voila!

Sunday, 5 April 2015

Core Rope Memory

This is a project that's been brewing for a while. I'm not even sure where I first heard of Core Rope Memory, but it didn't take me long to think "that would make amazing jewellry".

Core Rope Memory is a type of read-only memory that was used in the Apollo Space Program. Each bead in the picture above is a ferrite core which interprets a bit on each of the the word line wires (green) that either pass through it (1) or go around it (0).

I'm using the same principle to encode text using embroidery thread and glass beads. It can't be read unless you're willing to painstakingly follow the embroidery threads, but I hope to eventually be able to make wearable jewellry that can be read to a screen.

The first prototypes are finally ready, and I'm super excited.

The bracelet I'm wearing encodes the phrase "for the benefit of all" -- the motto of NASA.

I have plans for improving the design, including hiding the back of the stitching with another ribbon on which I'll write the encoded phrase. I'll also be developing a necklace.

I hope to sell these as custom orders at Octocon this year, and they should be up on my Etsy shop as soon as I get that sorted out, but you could leave a comment if you're desperate to order one now :).

Sunday, 1 March 2015

Tetris Cross Stitch

The text is an in-joke that I couldn't explain if I wanted to. I designed the Tetris pattern to be as satisfying as possible, with a long piece ready to fall into a perfect slot, and clear four rows.

If you're designing a Tetris pattern, don't forget that any rows that haven't been cleared should have at least one gap in them. There is no consensus on the right colours for Tetris pieces, so I just did the best I could with the threads I had on hand.

I've put together some kits including the strip of Aida (with finished edges), thread, needle and instructions. They'll be going up on my Etsy shop soon. Let me know in the comments if you'd like one, I'm open to customising.

Friday, 9 January 2015

Top tip: organising large paper-pieced patterns

I'm working on quite a large patchwork design using English paper piecing. I'm usually much less organised, and cut as I go, but this time I've cut and tacked all the parts before starting to stitch them together. I'm enjoying the apparent speed; even if it's not stitching up faster than usual, it feels like it is.

Anyway, I tried starting with 3 pieces that I was sure went together, but when I was done I realised they were very similar to, but not exactly the pieces I thought they were. I needed to lay the whole thing out with each piece in its correct position. But I don't have the room to store them laid out like that, and I certainly don't want to re-position them all every time I sit down to work on it. One of the joys of English paper piecing is that you can pick it up for five minutes and get a bit done.

I came up with a brilliant trick for keeping them in their relative positions: Blu-Tack *

I stuck all the pieces to A4 sheets in sections

which I could then stack and store in my craft box.

It's been working really well. I've had to consult my map a few times, but it's not nearly as much hassle and worry as sifting through a jumbled pile of patches would have been.

* known in Denmark as Elefantsnot ("elephant's snot")