Hand-crafted Charlie-Plexed Tile

This 5×6 LED tile is a key component in a secret project that I’m developing (in secret) with some other folks (whose names shall remain a secret).

Why be so public about something so secret? Because this tile uses a layout technique that lets you build charlie-plexed LED arrays quickly and cheaply — and that’s something worth sharing.

You need to flip the tile over in order to see what’s special about it. Here’s a quick list of features that make the assembly what it is:

  • The back of the tile has six “column” conductors and six “row” conductors.
  • These column and row conductors are connected along the diagonal of the row/column array.  At all other points in the matrix, the row and column conductors are isolated via a layer of masking tape.
  • LEDs above the diagonal have their cathode connected to the conductive row immediately above the LED.  LEDs on or below the diagonal have their cathode connected to the conductive row immediately below the LED.
  • All LEDs have their anode connected to the column that is to their immediate left.

The resulting circuit allows you to individually address any of the thirty LEDs in this 5×6 matrix using only six lines from a micro-controller. Continue reading “Hand-crafted Charlie-Plexed Tile”

MMMM: Monitoring Motion

Eyes!
photo by peej

That time is once again upon us! This coming Monday, October the 10th, is our second installment of the Monthly Monday Microcontroller Madness series!

 

This month’s workshop will feature the concept of motion sensing in relation to microcontrollers. We’ll be taking a look at passive infrared sensors (PIR) for motion detection, ultrasonic range finders for distance measuring, and even looking at how to integrate a webcam into your Arduino project for motion analysis. These sensors and techniques are great for adding to your Halloween projects (wink, wink).

 

In addition to talking about motion, we will be offering our usual advice and guidance to those currently working on projects, or looking where to get started. All skill levels are welcome and we look forward to seeing you on Monday!

 

UPDATE: Here’s a link to the Arduino Reference page for the Parallax ultrasonic sensor and a code page for the Parallax PIR.

Manufacturer information can be found here and here, respectively.

Monthly Monday Microcontroller Madness @ Hive76

Pile of Arduino things. by Andreas Wetterberg
Pile of Arduino things. by Andreas Wetterberg, on Flickr

Starting at 7 PM on Monday, September 12, Hive76 will be starting a new ongoing monthly workshop focusing solely on the wonderful world of microcontrollers.

“What’s a microcontroller,” you ask? Let’s take a quick glance at the Wikipedia page!

“Yeah, so?? Why should I care?”

“What if I’m familiar with microcontrollers, and I’m just looking for a place to talk shop, jump-start a stalled project, or help other folks learn a thing or two?”

  • Come on down!!! (up, or over also apply here)

Great! Now that you’re coming, what can you expect?

You can expect to be welcomed into a friendly environment and you are encouraged to bring your ideas, aspirations, projects, and most importantly, your questions! Individual projects, group projects, build challenges, basic skill instruction, hardware buying guidance, and experts on hand! I would like to emphasize that this workshop is open to complete beginners. No prior experience with electronics OR programming needed! We’ve all got to start somewhere!

PIC, Basic Stamp, MSP430, Arduino, etc… no microcontrollers will be turned away! This is an all-inclusive, open workshop to promote learning!

The Fine Print: Materials will be available for use within the space and a limited amount of hardware will be available for purchase. If you’ve got a laptop or netbook handy, please bring it along. Instruction and guidance will be available free of charge!

(Donations are always appreciated)

 

This workshop is brought to you by: KBI, Inc.