Control Matters
SPLat Controls' aperiodic newsletter

16 March 10
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All together now: One  - Two - Pee!

The water supply authority in Edmonton, Canada, has published a graph showing water consumption during the recent Olympic men's hockey final. There's no doubt those Canadian take their hockey very seriously. The peaks in consumption are accurately synchronized to the intervals between game periods. I wonder what other social engineering uses graphs of utility consumption could be used for? Do the TV ratings people use them as part of their input data?

David Stonier-Gibson

In control - Stuff about or related to control systems

Failing to design is designing for failure

If you are new to programming the temptation is to just get in there and "cut code". It feels righteously productive to have an impressive slab of code to show as quickly as possible. In fact, rushing in and cutting code straight off is the least productive thing you can do. Going straight to code is like starting to build a house by sawing up some timber and banging in some nails, without any plan or blueprint.
 
Before cutting a single line of code you need to have a very clear, preferably written, understanding of what the program is to do. Then you need a design. The design is essentially a plan that breaks the task at hand down into subtasks or functional blocks that are each responsible for some part of the overall program objective. Techniques you can use here are flow charts, state diagrams, decision tables or whatever else works for you. The vital point is to understand and map out the functionality independently of any code.
 
A well thought out design becomes not only a plan for generating the code. It is also a guide for testing and debugging. Later, if changes are required, the design becomes a map that allows you to find your way around the code and mentally test, in the abstract, the effects of proposed changes.
 


Out of control - Nothing much to do with controls, (but interesting)

Making reading easier for some 

Some of the brightest people I know have difficulty reading printed material. In some cases this is due to a condition called dyslexia. One of our customers admitted to me, during an all-night project marathon, that he is dyslexic. He is a very bright and creative fellow, and can work well with diagrams, but printed words are just about impossible for him.

There is a technique that helps some dyslexic people to read more easily. That is either to wear coloured glasses or to have the text printed on coloured paper. The optimum colour varies, I believe, from person to person. The son of one of our employees was angry and disruptive in class. His teachers had labeled him as a trouble maker, and nearly flunked him out of high school. His mother identified the problem as dyslexia, got him special computer software and special (expensive!) e-book versions of his school texts, and he turned into a straight-A student in a couple of months.

A much cheaper way, if you have the text as a pdf file, is to use the Foxit pdf reader. Foxit is a free alternative to Adobe pdf reader. Foxit lets you set the background colour on most documents (it doesn't work on all pdf documents because some are simply scanned images of pages). Download Foxit Reader here.

Have you seen our easy to digest Finite State Machine tutorial?

"As someone involved in electronic & software development and who already employs FSMs in my coding efforts, I found the tutorial too elementary for my needs. I'm sure that there are engineers who would be lacking FSM concepts who would benefit.".

 Steaphany Waelder, Texas

Exchange between Winston Churchill and Lady Astor:
She said, "If you were my husband I'd give you poison."
He said, "If you were my wife, I'd drink it."
 

C++ : Where friends have access to your private members. 
Gavin Baker

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Copyright 2010 SPLat Controls Pty Ltd. This communication does not constitute professional advice