We had a great turnout at Andrew’s LED workshop. It was attended by regular Hacklab members and some new faces who were visiting the lab for the first time.

Andrew discussed the basics of how semiconductors and diodes behave, and how to calculate the related currents and voltages in the circuit. He showed to drive low-power LEDs simply with a current-limiting resistor, and the limitations of that design. He went on to show a circuit for an active constant-current method of driving high power LEDs, and demonstrated various models in LTSpice.

Thanks to everyone who attended the workshop, and thanks to Andrew for presenting it! Watch this blog (and our @hacklabto Twitter) for notices of future electronics and craft workshops at the Hacklab.

Tim presented to a full house of interested Hacklabbers, fielded lots of questions, and sparked some interesting discussion on the nature of democracy. Thanks, Tim!

Tim’s Liquid Feedback Slides.

• Read an LED datasheet
• Calculate parameters for your circuit
• Drive high-power, super-bright LEDs
• Boost efficiency and brightness without blowing up your LED

Non-members are welcome, but a cash donation to the lab would be appreciated.

It’s been a great two years — lots of projects, memories and friendships. The result of our efforts is a fun, well-equipped and sustainable hackerspace in Toronto!

Come celebrate with us, show off the lab to your friends, or check it out for the first time.

Show up after 7pm, and bring along some drinks or snacks, if you intend to be hungry or thirsty. Check out the sidebar of the blog for information on how to get to the lab.

Street Level: Behind the doors of HackLab.TO.

Check it out.

Andrew Kilpatrick: Moving Sign 2

In order to make the panels easy to use for members, we’re going to permanantly mount them on the wall over the stairs.  They’re going to be attached to a nice painted piece of plywood (steev!) and wired up to a server.  We’re going to do some circuitry to allow the sign’s power to be automatically controlled.

We’re going to interface the LED panels with a host computer using an Arduino.  Our previous efforts pushed the limits of the Arduino’s performance, but we were running completely unoptmized code.  Hopefully with a few tweaks, and by getting a bit more low level, we can move the serial data fast enough for an adquite scan rate.

The Arduino’s USB Serial interface will be used to interface the sign with the host computer, which will most likely be running BMix with a custom output plugin.  BMix is software developed by Andrew, Dan and Jonathan for the Blinkenlights project in Toronto, and is very good at controlling a matrix of lights.  It will allow the display to be operated using a standard UDP protocol which already has lots of language support, and will also allow it to be easily shared between a number of users and applications at the lab.  There’s even a video game API.

This is the start of the project and the basic design… More information, photographs, and geeky details will be coming as we dig deeper.

Jonathan, Andrew and I are starting a new Java Users Group in Toronto. Our group is meant to
hold better appeal for geeks/hackers, to actually hold a meeting every month, and to put a bigger emphasis on socialization with and contributions from all group members. Through 5-minute lightning talks (impromptu and prepared are always welcome), we hope everyone will have a chance to participate.

Vital stats:

Meeting night: 3rd Thursday of each month
Start time: 7:15
Location: the hacklab
Web Site: http://tjug.ca

The monthly agenda will include:

* group discussion of recent Java-related headlines
* lightning talks from anyone who has something to show&tell
* a robocode battle
* at most one longer-format prepared talk (30-45 minutes max)
* a visit to a nearby pub!

We hope you’ll join us for a fun evening of Java!