[sdiy] rotary encoder?

[Cary Roberts]

>> I emailed Mark this suggestion privately last night. But the only
>> reason to do this over a microcontroller is if you wish to avoid
>> using a
>> microcontroller. A small PIC is a quarter of the cost (and less than
>> half the board real estate) of a design using 74LS148s.
>
>Hm, sure about the cost? We'd need a device with 16 I/Os here, 12 in
>and 4 out.

In single quantities the 74LS148 is $1.20US and a 7408 is $.56.  Don't
forget 12 10K resistors for pull up.  A DIP 16F57 microcontroller is $1.02
which would support a standard 12 position switch.  If you used a graycode
encoder you could do it with a $.66 16F54.  SMT PIC parts are less moolah.
You'd need a crystal for these low end PIC parts but that's under $.25 in
single quantities.

When you start counting board real estate the PIC solution will save you at
least 2 square inches which is worth at minimum $2 assuming a double sided
PCB with solder mask in low quantity.

-Cary