any1 have a circuit for a 4-button footswitch w/LEDs to 2-bit binary?

[Dr Ron]

I'm designing a circuit that has a 4-button footswitch where only one is on at a time.
An LED will light above switch A, B, C, or D (and the other three LEDs will turn off).
The circuit also needs 2-bit binary output - 00, 01, 10, 11 for addressing.

I've been R.G. Keen's bypass switching with CD4053's as a starting point,
but this doesn't turn off the other LEDs.

Does anyone have a circuit/schematic for this that they'd be willing to share?

Thanks!!

[R.G.]

The circuit for one of N activated circuits is already designed - see figure 7  in "A Programmable FX Switching System"  at
http://geofex.com/Article_Folders/fxswitchr/fxswitchr.htm
for how to make one of these from a 74C373. (Note - 74HC373 will not work)

As for the encoding, it only takes two resistors and four diodes to make a binary encoder. The resistors pull down the output bits to zero, the diodes pull up the appropriate bits from the one-of-N outputs.

[Dr Ron]

Thanks RG!!!!

Would I use the DM9314 Quad Latch instead of the 74C373 Octal Latch, since I only need 4?
(There are a few Quad latches to choose from http://www.chipcatalog.com/Cat/168.htm)

Thanks again!