robmil said:
Hi
I have a signal switching circuit which is based solely on momentary push button and relay activation. I would like to convert part of this (volume up and down) to a rotary type. I'm not too up with rotary encoders etc. Is this a simple exercise converting up/down buttons to rotary encoder?
thanks
Rob
Hmmnn Simple is such a subjective term,
Rotary encoders must be decoded in order to make them work.
Try doing a search on gray code (a common type of encoder) to get an explanation of how it works.
You really need a processor to convert the movement of the rotary encoder to volume up and down commands. You could use a PIC or AVR controller, but this is going to take some programmming.
Maxim make a digital volume pot the MAX5440 which can take the signal direct from a rotary encoder however it only comes in a surface mount package. I have played with trying to get it to work but failed. I got fed up eventually. I have bought a pic programmer and eventually will get round to learning JAL properly in order to get the same result.
Alternatively there are a couple of people here who have programmed chips to do this. You could look through threads and ask nicely for some code. You would still need a programmer of some sort.
I an determined that eventually I will get one to work. But I dont see it as a venture that i will be able to complete in the short term.
Hope my experiance isn't too much of a downer on your idea. Rotary encoders are way cool. Digital pots have some big advantages over stereo wipers in terms of size and tracking between channels.
Push buttons are a bit easier. Maxim make a chip called the DS1802 which can be ordered in DIP and is easy to kmnock up into a design. It is limited by the voltage of your line in. Pedja Rogic has details on using this chip on his web site.
