Red And White LED Dresses

I’ve been experimenting with electronic fashion since about 2012. In that time I’ve never produced a finished garment that someone might want to wear. I’ve just created example pieces showing the techniques and/or capabilities of the technology.

This year I wanted to do something different and have something real to show at the many maker events I go to throughout the year. The problem is that I only have a limited set of hand sewing skills. The solution was to find a person to collaborate with.

That person has turned out to be my mother, Dolores Fitzsimons. She has over forty years working in the Irish fashion industry as a pattern maker and designer. I think that makes her very qualified to help me implement my design ideas.

Initial Research

We began by looking at some of my existing example pieces. We found the LEDs to be a bit harsh and they would need to be toned down a bit in a finished garmet. Experimenting with placing layers of different fabric in front of the LEDs, gave some promising results.

We visited some local fabric stores in Dublin, and found that Organza fabric produced a very appealing diffraction effect when a clear LED light shines through it.

So after some more design discussions and these visits we decided to start off with something small and design a dress for a young child.

Little Red LED Dress

The outer layer is an interesting red Organza fabric with a textured silver swirl pattern, with red netting layered on a red cotton fabric. The electronics are 24 red LEDs, driven by a 3 SEWIO8‘s and a LilyPad Arduino USB micro controller.

The dress should be suitable for girl about 3 to 4 years old. More details of the design and construction can be seen in the photo album.

White LED Dress

The second dress is made with a body of white Duchess Satin, a sheer neckline in white Organza and a multi layered flared over skirt in white Organza. The dress body is fitted, has princess seams and a curving high-low hemline.

The electronic are 28 SEWRGB pixel’s which circle the body following the curve of the high-low hemline and a LilyPad Arduino USB micro controller.

The intention wasn’t to make a wedding dress but it could be used as one. More details of the design and construction can be seen in this photo album.

Upcoming Events

We planning to create another garment, but this coming weekend (April 26-25) I’m heading to Newcastle for Maker Faire UK as part of TOG

In May (May 17-18) I’m heading to Maker Faire Bay Area for the first time, one of the reasons for wanting to create some real garments.

Later in the year I’d like to show my designs at Dublin Maker and Maker Faire Rome.

Aurora Lamp

Aurora LampOver the first weekend in March I took part in the first Science Hack Day Dublin an open data hacking event hosted in Dublin City University. The challenge was for participants to come up with open data related project ideas, to form groups, work on those projects and present the results all within 36 hours.

Some initial project ideas were collected on a wiki page in the days before the Hack Day. Part of a set of interrelated project’s caught the eye of one of the organisers and he suggested that the submitters get in contact with me for some input and maybe to help.

All the Aurora Orrery project’s revolved around the Aurora or in the northern hemisphere Aurora Borealis or Northern Lights. Which are caused by charged particles from the sun effected by the earths magnetic field interacting with the upper atmosphere. The result is a spectacular light show in the sky which is more visible as you get nearer the polar regions. But given a high level of of solar activity and favorable weather patterns, the Aurora can be seen from Ireland in places like Donegal and other parts of Northern Ireland.
Continue reading Aurora Lamp

LED Matrix Display

Last Sunday I gave a workshop in TOG as part of it’s Engineers Week 2011 activities. We spent the day assembling a 8×8 Red/Green LED Matrix Display circuit which I designed in strip board.

The circuit forms an interface between a micro controller and a 8 by 8 Dual Colour Common Anode LED Module. This type of module has two LEDs per pixel, each row has 8 pixels, with 8 rows. The anodes of each LED in a row are connected, with 16 columns formed by connecting together the cathode of an LED from each row.

A high side switch is needed to turn on/off a row and must be able to source approximately 240 milliamperes (16 multiplied by 15 milliamperes). A low side switch is needed to turn on/off a column, but only one LED is on per column so it only needs to sink 15 milliamperes.

For the high side switching I used a TD62783APG 8 Channel High-Voltage Source Driver from Toshiba Semiconductor. It’s very important that only one output from the TD62783 is on at any one time so I used a 74HC238 3-to-8 Decoder from NXP to control the row selection. For the low side switching we used two 74HC595 8-bit Shift Registers from NXP.

Only one row of LEDs is on at a time, the display uses persistence of vision to give the illusion that all the LEDs are active at one time.

The basic operation for displaying a single frame is. The data for a row is shifted into shift registers one bit at a time, the shift register output is turned off (OE), the row is selected on the decoder, the shift register data is loaded into the output registers (LE) and then the shift register output is turned on. These steps are repeated for each additional row of data. All the steps are repeated indefinitely until the next frame of data is to be displayed.

The circuit was designed around the Arduino micro controller but should work with other micro controllers. The connections are shown in the image. The left hand side of the display is the row select pins the central pins are for power and ground, with the columns connected to serial peripheral interface (SPI) pins on the Arduino on the right.

Dual 8×8 Matrix v0.1 Schematic

I’ll do a follow-up blog post with the source code and a Java program I’ve written to create animations.

LED Badges

Just after getting back from 27c3 in early January Jeffrey and myself got talking about a project for TOG’s Paddy’s Day hackaton.

Our general idea was to create a little badge with LEDs in the shape of a shamrock. We were hoping for something small, light and bright with lots of LEDs. I said that I would do some more research to see if it would work and if it did to come up with a suitable circuit design.

I knew the general idea was to use a step-up (boost converter) to increase the voltage level so to that I could drive a string of LEDs. I then began to search manufactures sites for suitable components and relevant information.

After searching all the main contenders I found a very interesting range of chips in a small five pin surface mount package from ON Semiconductor. The most interesting options were the CAT4137 LED Driver, Boost, 5 LED and CAT4238 LED Driver, Boost, 10 LED. Another option from Linear Technology was the LT1932 – Constant-Current DC/DC LED Driver in ThinSOT. As I wasn’t sure what would work I ordered a couple of each component and the suggested supporting components. Along with lots of green surface mount LEDs.

I then designed and etched a simple proof of concept board. After soldering it up and connecting up a CR2032 coin cell battery it worked but I was disappointed with the brightness of the LEDs.

I then put the project on hold. Roll on a couple more weeks and I looked at this project again.

Investigating the proof of concept board I realised I had used a wrong resistor value and was trying to supply 30 milliamperes instead of 10 milliamperes into the string of LEDS. Changing this didn’t really help increase the brightness. But it did point me in the direction that I was just trying to draw too much current from the battery.

I found the following blog post on using cr2032 coin cells from Marcus from Interactive Matter (who I meet at 27c3) very informative. Connecting up the circuit to two AAA batteries solved the brightness problem.

I have now reworked the board into a near final layout. And as a token gesture to the 14th of February (Valentines Day) I’ve created a design in the shape of a heart.

Tomorrow I’ll finish the prototype of the shamrock badge and post a picture. If I created a kit would you be interested in buying it?

Update: Here is the photo of the prototype for the shamrock badge. When we looked at it after I assembled the badge it was hard to make out the leafs also I might change the resistor value to increase the brightness.

Engineers Week 2011

Next week I’m helping to run a number of events in TOG for Engineers Week.

I’ll be helping Jeffrey with his free Arduino 101 – Learn to Blink on Tuesday, the Soldering Workshop on Saturday and I’ll be giving a new LED Dot Matrix Display Workshop on Sunday (I hope to do a write up soon).

During the week I have a number of Arduino Uno‘s boards available for €30.

Also over the weekend I’ll take part in the Synchronous Hackathon and I hope to have time to help with TOG’s Hackerspace 555 Timer Challenge entry for the 555 Contest.