Demux

[xnihilo]

Hi guys!

I need to redirect voltage from the input to one of many outputs, in sequence, everytime I put a voltage pulse on the input pin.
Imagine there are 16 outputs available, I connect a led to each output and I want that everytime I pulse the single input, it turns of the previous led and turns on the next led, like some sort of sequential switcher but I have merely one or two PIC pins availables to control the multiple output device.
Does someone know if such thing exist? Maybe a Demultiplexer of some kind?

[mackrackit]

You are looking for a shift register. Takes three pins to run 8 out puts, 4pins for 16 out puts if you use two.

If I remember a part number HC595. That might be for in put. They have them for both.

[xnihilo]

This kind of thing. I know there are Demultiplexers (I have the datasheet) but I need a device where I have an input and a strobe line and multiple outputs. Everytime I use the strobe I switch to the next outpput :'(
I don't have 4 outputs left on my PIC.

[mackrackit]

Just a thought to make one.

Find a PIC with enough I/Os. 1 input and 16? outputs.

Code something like..

If PIN_IN is high then
count = count +1
If count = 1 then high LED1
If count = 2 then high LED2
so on and so on...
If count = 17 then count = 0
Start over.

Every time PIN_IN goes high the counter increases.

[xnihilo]

Just a thought to make one.

Find a PIC with enough I/Os. 1 input and 16? outputs.

Code something like..

If PIN_IN is high then
count = count +1
If count = 1 then high LED1
If count = 2 then high LED2
so on and so on...
If count = 17 then count = 0
Start over.

Every time PIN_IN goes high the counter increases.

Sure, but i was thinking about a cheaper solution. Such pic costs over 3usd. a demux is about .60 usd. i can't beleive such step-up switch doesn't exist.

[sayzer]

4017 is what you need.

You can have as many as you want with cascading.

A single pulse is good enough for all.

[xnihilo]

That's exactly what I was searching for.
Thank you for your help!