Some 12 years ago, I was presented with an interesting problem when I was designing the KWM-4 (my answer to a solid-state Collins KWM-2). My KWM-4 was a multi-band radio and thus the problem was how to switch the circuitry for the various bands.
The last on the list of candidates was a multi-deck, multi-position switch. I should mention that for the LO I used a Si-570 kit from K5BCQ. As a bonus of that design for the "channels" you picked, each one could generate a unique 3-digit Binary code (this is like saying jumbo shrimp).
Essentially the K5BCQ kit had 999 channels and once you called up a channel you would tune frequencies using the encoder within that channel range. One panel button lets you move a menu through the ranges (bands) and for each range (band) you can set the binary code.
S0 now how to take that binary code, decode it and switch banks of relays on the BPF and LPF. This is how it was done and now installed in the KWM-4. This is nothing more than a binary to digital decoder. For every Binary code created one pin on the IC is hot and fires the transistor (or P Channel FET) controlling relay sets. With 3 binary inputs that gives you a potential of 8 bands. Four inputs yield 10 bands.
Today I would use a Mega 2560 to do the Si5351 and the band switching. (The 2560 has more IO and a much larger program space.) This also screams a 4X4 keypad -- just like the Big Boys.
K5BCQ's used an approach similar to mine but used the CD4028 which had the decoding and switching all in one device.
Thus, this little slick circuit can enable you to do all sorts of things. How about a small handheld transmitter that generates a binary code which is decoded on the other end for a set of determined actions.
How about watching from the bushes when that nasty neighbor's dog takes a dump on your grass-- you set off the sprinklers or maybe start up a magneto pumping volts into the grass. Don't you just love technology? Today many things are possible.
73's
Pete N6QW
CD4028
