[sdiy] Shaft Encoders (was "illuminated switches")

[Olav Martin Kvern]

Eric Brombaugh wrote: "The quadrature signals don't go through a full cycle 
for each detent -  Boo! Rather, the detents are every 90deg in the 
quadrature sequence. This behavior makes these encoders incompatible with 
the more common Alps variety where the detents are spaced every 360deg in 
the quadrature sequence. Firmware and/or hardware decoders designed for Alps 
won't work correctly with these encoders - you'll have to cycle through 4 
detents on these encoders to register 1 pulse on a decoder designed for 
Alps."

If anyone needs to read them with an Arduino, the sketch from the Playground 
section (of the Arduino site) works reasonably well, even though it was set 
up for an Alps type encoder. It'll increment/decrement the value you're 
working with once every two detents, which is good enough for me.

The push switch is fun. I've been using it to drive a menu system that 
determines what value the encoder is editing. This user interface "feels" 
good--somehow, it's much better than having a separate push button to 
perform the same function.

Thanks,

Ole