Digital selector switch SP4T


I'm building a multimode analogue filter for a synth project I am working on. I've been following some schematics I found in the wild.

The project is working nicely on the breadboard so far but I have to use a mechanical SP4T rotary switch to patch any one of my 4 outputs (Notch, HP, LP, BP) to my audio output.

I'd like to do away with the rotary switch and replace this with a single momentary push button. Each press of the push button will switch to the next output and keep going for every push. I would then use 4 LEDs to indicate which output was in use.

I'm reasonably new to all of this and really must read up on my logic IC's and their applications.

I'm thinking this would be done with an octal latch maybe? Any ideas?

Best Answer

If your circuit runs from +5 only your signals must be between 0 and 5V, right?

If so, the easiest way might be to use a 74HC4066 + a 74HC4017 + a 74HC132 (to debounce the pushbutton and for reset). You can use 4 low-current LEDs and a single resistor to indicate which output is currently active.

The 5th output (Q4 if they're numbered from 0) goes to the reset input so that it only counts from 0..3 (for four outputs).. if you feed it through two of the remaining three gates, you can use another RC to reset the counter to 0 at power-up.