Control Matters SPLat Controls' aperiodic newsletter

13 Aug 2009 View online

SPLat/PC is getting a major upgrade 

We have been quietly working for some time now to convert our SPLat/PC programming software from a 16-bit to a 32-bit application. SPLat/PC was originally written for Windows 3.11, using Microsoft tools. Subsequent changes in the Windows operating system have produced an ongoing series of compatibility problems. The final straw is that Microsoft are apparently totally dumping support for 16-bit applications in their 64-bit systems. 

A beta release of SPLat/PC 32-bit version (aka SPLat32) is now available, and you are invited, nay, urged, to join in the beta testing program. Functionally it is virtually identical to the old version, but the Translate process (compiler) is about 5 times faster. Once it is stable and able to replace the 16-bit version entirely, we will start adding enhancements starting with 5x faster program downloads.

So join in and help us get this happening.

David Stonier-Gibson

Get grounded!

Probably the most important conductor in a control system is "ground" or circuit common. This is the conductor to which all other circuits are referenced, and in an ideal world it would have no electrical resistance or inductance. But alas, in the real world it does. That means there are a few things we have to do to make sure that our control systems work as expected.
 
The best approach is to wire all of the common or ground wires separately back to the power supply common terminal (often called minus). This is called a star point grounding scheme as all of the circuit ground wires "star" out from the power supply ground or negative terminal. With this scheme, if you are measuring an analog signal and in the same control system, switching large currents, the voltage drop in the ground wires for the large current loads does not flow in the ground wire for the analog measurement, thereby avoiding changing the analog reading.
 
Using a star point ground system can also stop the "it does something strange every now and again" type problem, by routing noisy currents away from more sensitive circuits.
 
In general always keep your ground wires as short as possible and use the thickest conductor that is both practical and of course matches the circuit current.

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

Make your own UAV (Unmanned Aerial Vehicle)

Chris Anderson is editor of Wired magazine. He has also been working on development of UAVs (aircraft that fly themselves, quite different to simple remote control). Uncle Sam pays $4M for a Predator missile armed UAV. Chris has unarmed designs from $100 for an indoor blimp up to $600 for a fully functional, autonomous aircraft that flew a camera over the Google campus and revealed a cheat on Google Earth.  He doesn't use SPLat controllers, but what the heck? I just wish I had time for this kind of thing.

Get the full story with This 27 minute video. It is absolutely fascinating.

Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the universe trying to build bigger and better idiots. So far the universe is winning.
Rick Cook

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