Re: [sdiy] µP controlled analogue switches

[Michael Buchstaller]

>(expensive) parts from analog devices but all without latch. Or is there a
>better solution?

How about using one or more 8255 to make more output lines ?
They are inexpensive, 24 outputs each and need only 2 lines for the
address (4 registers - 3 data and 1 control register), read,write and
CS line.

If you connect the data lines to an AVR port and the address and write 
lines to 3 bits of another port, you could use the highest 5 bits of that
port to address 5 of these chips without any more circuitry. That would
make 5*24 = 128 output lines).
Or you feed 3 of the 5 lines  bits into two 17LS138´s address lines and
use the remaing two lines to select the LS138 - so you can simply use
16 8255 chips (12*14 = 384 lines) - that schould be enough.

and you have used only 2 AVT ports this way !


-Michael Buchstaller