Saturday, February 9, 2013

Charlieplexing and YOU!

I was in the lab last week and we got onto the topic of seven segment displays. Someone then proposed the challenge of driving it using only 4 I/Os without a driver. A very interesting challenge indeed.

After much deliberation they finally shared the secret of Charlieplexing. This is a basic way to control large arrays of LEDs using just a few pins. In fact the equation works out as follows:

L = n^2 - n

Where L is the number of LEDs controlled and n is the number of pins that are used.
Personally, I love this. I love LEDs and I love controlling them. Some possible project include using this method for larger LED cubes, 7-segment driving, and other fantastical inventions.

Anyway, The circuit is actually pretty simple and available at the end of the video above. As for the code, it is just a matter of reassigning the pins to output or input on the fly and then changing the state of the other outputs. This goes into how it works. With a 3 pin setup, one pin must be changed to an input or high impedance state. The other pins act as your outputs and depending on which one is set HIGH or LOW you can have individual control.

There are drawbacks, Can't control multiple LEDs at a time (i.e. light 1 and 5). the way around this is to actually "flicker" the LEDs involved at 60hz which is unnoticeable to the naked eye.

For more info, Visit the Wiki.

Wednesday, February 6, 2013

Shout out to my Friends in Germany.

Hallo Freunde aus Deutschland! Es scheint, als ob ich hatte einige Besucher aus diesem Teil der Welt. Derzeit ist mein Deutsch schlecht, so verwende ich einen Übersetzer bin. Sorry, ich werde daran arbeiten.
Dieser Beitrag ist meist nur ein kurzes Hallo und ein kleines Snippet von dem, was mein Blog über. Hier werde ich für elektronische Führungen Bewertungen und Erfindungen, die ich arbeite.

Tuesday, February 5, 2013

Raspberry Pi setup, First Run, How to, and Good times.

Got my Raspberry Pi the other day..

Here's how I set it up for the first time.
Check out the video.

It's a pretty straight forward setup actually. Most of the instructions can be found on their website. 

Some possible projects?
Well my next installment will show you how to hook an Arduino up to it and operate it from python.
We could look at hardware considerations, make the platform MORE portable.
I'd like to get a small screen for it, maybe see if it has bluetooth support?
Anything really, Suggestions?

Friday, February 1, 2013

Adafruit Arduino Protoboard (part of today's shipment)

Today has been a Day. A day which will stick in memory for a long time. 

Pushing beyond that, Moving forward if you will, I would like to present you all this. A small compilation I created that covers the basic assembly of the Adafruit Protoboard Shield. A very impressive bit of hardware if you ask me, Highly recommended. You can pick one up here.

While you're there check out their other wares and let me know if you find anything interesting.

Oh, side note, Comments are now enabled for people without accounts. Share your thoughts!

What Mysteries await?

Here at the University I got a fairly large shipment in today and boy does it feel it Christmas!

Here's a photo of the mystical brown boxes that contain magical wonders and dreams. What could they contain? Where did they come from? What fabulous creations will come of this?

Ok, ok, calm down. We got this and I will be updating you all soon as to what mysteries they contain.