Tuesday, December 25, 2007

Merry Christmas



Just thought I'd wish any passers by the best wishes for the solstice and upcoming calendar year.

Sunday, December 9, 2007

My attempt at stop motion

video

So this may seem a little bland, but it is the very first attempt for myself. I have spent the last few weeks helping the rest of my family with their projects.

The intent is to take the three segments and blend them together, much the way it is done in the 1982 Polish film "Tango".

It's also my first video post here on blogger, let's hope it doesn't take too long to download for you.

Update - Though I had taped down the baseplate and tripod, using the release button on the camera caused the camera to move - there is no cable release for that Kodak. This caused the wobble. I used a regular halogen desklamp for even lighting, the extension ring for the close up lens actually casts a shadow when the on-body flash is used, which leaves the lower left un-lit. Lego is also shiny, and flared horribly with direct flash.

Tuesday, December 4, 2007

Aardvarks, Beagles and Cheetahs.

This strange sounding menagerie is actually some of the contents of my tool box. They are
such handy tools that I feel I have to blog about them. Actually I only have the Aardvark and Beagle, the Cheetah was more than I needed price and performance wise.


I have spent a lot of time over the last few years working on I2C and SPI interfaces. I always had the luxury of a DSO (Digital Storage 'Scope), MSO (Mixed Signal 'Scope) or LA (Logic Analyzer) to assist me. However even the best LA I had access to was not a protocol analyzer, and could not easily be configured to tell me what transactions were happening. Those who do this for a living know what I'm talking about, you end up counting bits and trying to find ends of bytes, words and packets in a mess of green square waves.

The Beagle allows you to watch what is going on, it is a true protocol analyzer, and for about only $300. The Beagle is a dual mode I2C and SPI monitor. It also can monitor MDIO, which is something I don't yet have to deal with. I2C to 4MHz, SPI to 24 MHz.

The Aardvark is a little different. It can monitor I2C and SPI , but only to 125KHz I2C. Where the Aardvark start to shine is when you want to develop an I2C or SPI slave, the Aardvark can be configured as a master. Here you can drive the bus from your PC, and exercise your target. You can also use it as a golden reference if you are writing the master.

The Aardvark can also drive 8 bits of GPIO, only low speed, but enough to exercise a few inputs on the target board, just what you need to simulate a lot of user input over time. It can also capture about 1000 8bit samples a second.

The software that comes with it is easy to use, and intuitive, even if there are a few funky things in screen refresh cascades (every time data is refreshed all the buttons seem to repaint too). They also provide a full API and code samples in VB, C#, C++, Python, XML you name it.

I actually ended up buying the programmers kit, the bundle with both devices and a few cables, and a developers board. The $500 bundle has already saved me a couple of days work, so it has paid for itself.