Hi Tom, Nice program! However, often hardware and/or software decoders can be made simpler if the code wheel contains an asynchronous track that provides the oversampling clock signal, these are often called A+B+Z quadrature encoders. I don't see any wheels on your Web page that provide the Z clock signal.
Here is a link to a page with a good explanation of decoding: www.fpga4fun.com/QuadratureDecoder.html Here is a link to an encoder with A+B+Z outputs: www.cui.com/adtemplate.asp?invky=455913 You might want to mention that if you print the code wheel to a piece of overhead transparency film, the wheel can then be glued to a thin clear plastic disk you cut from the lid of a food container. The transparent code wheel is then easily used with transmission opto-detectors salvaged from a cheap mouse. Sometimes the mouse will even have decoder chips on them that can be re-used. Lastly, a while back I stumbled across a page that gave detailed instructions on how to build an encoder using a code wheel mounted to the dismantled shaft of a standard through-hole mounted potentiometer. But now I can't seem to find it again. Have you seen this page? If-so, perhaps you have a link. 73's, David --- In [email protected], Tom Lackamp <[EMAIL PROTECTED]> wrote: > > I've just released a freeware program to generate > codewheels. > > The program can generate a number of different > types of codewheels, several of which are suitable > for building your own quadrature encoders. > > The codewheels can be printed on any home > inkjet or laser printer with absolutely no > hassle. The codewheels are automatically > printed out at designed size. > > One of the included codewheel types, the > two-track quadrature codewheel, > is particularly applicable to homebrew quad > encoder projects. With one of those wheels > in hand, you can build a good encoder with > a minimum of mechanical precision required. > > Other wheel types are suitable for robotics, > transport, motor control, and other apps where > the direction of rotation is known. For advanced > constructors, there are two absolute position > wheel types available. > > Windows XP/Vista capable, .NET not required. > > http://www.mindspring.com/~tom2000/Delphi/Codewheel.html > > Have fun! > > Tom Lackamp >
