This projects started as 2 channel DMX switch based on fog machine I found on the web. I wanted more channels, so I added a simple SPI implementation that reads the channel swiches connected to HC165 shift registers. That freed up a stack of pins.
I also wanted to use rotary BCD switches, so I would not be asked by other uses how to set up the channel selections. 4 additional switches are added to future expansion.
VER 3 added 18/04/2006 uses arrays for data channels.