Sunday, 7 August 2016

On vaccinations

I'm not sure how old I was when I almost died of measles. I can still just about remember the feeling of desperately trying to breathe. Back when the memory was clearer I asked my mam about it. I described the coughs that just kept going out, and the feeling that my lungs might never open up and let air in again. Was it whooping cough? "No", she said, "you had a very mild dose of whooping cough. That would be when you had measles. I'm surprised you remember. We thought we were going to lose you."

A couple of years ago a child I know was hospitalised with a high fever. Thanks to vaccination, measles has become so rare in Ireland that the hospital didn't even test for it, but when they came home the little one developed the classic rash. He had come in contact with someone who had measles, before he was old enough to get the vaccine.

That person, the one who gave my friend's child measles, may not have known they were sick. Not everyone who gets measles gets a bad dose. But the really powerful thing about vaccines is that so few people get any dose at all that the disease has nowhere to go. If everyone who can receive a vaccine against measles does so, the pockets of fertile land for the disease (people on immunosuppresants medication, kids too young to be vaccinated, the small percentage of people in whom the vaccine doesn't work) are so few and far between that the disease can't survive. We could make it *go away* like we did with smallpox, and have nearly done with polio. For my mother, polio was a fact of life. For me and my children polio is a fact of history.

And that's why you have a responsibility to vaccinate your kids.

I don't say that lightly. I've seen the injection-site swellings, and the vaccine-night fevers. I've winced and bitten my lip as my babies cried because someone stuck something sharp in them. But just as I have to teach them not to steal or hit, I have to teach their bodies not to pass on deadly diseases.

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: