4 state pushbutton switch with shift register?

[krabbacitor]

Hi there!

I'm just curious... I thought it would be nice to have a single debounced pushbutton switch, which would close one contact (of four) on each successive pressing, like this:

no signal: on - off - off - off
first push: off - on -off - off
second: off - off - on - off... and so on

could one use a 4-bit serial in parallel out shift register? (i'm STILL a newbie... )
i thought about trying this with a cd4015 cmos but couldn't find a working ltspice model for this...

does somebody have an idea, if this works at all or if there's some model for it available? as yet i've been unlucky...

regards
christian

[JovianPyx]

Initialization of the shift register to state on-off-off-off is the issue using a shift register. This must be done at power up.

A 2 bit binary counter and a "1 of 4 decoder" might be easier I think, though it will be at least 2 ICs. The debounced switch provides clock to the counter and the counter outputs drive the "address" lines of the decoder/selector. If the counter is simply cleared at power up, it will initialize the output state to on-off-off-off.

[metal_head_82]

Thought about the same thing last evening...
Though I'm still a n00b to all this I came up with the same solution.

But I'd use a 4052 - that way you can have 2 buttons
Of course you would need a second counter BUT it's still a nice and easy way.
AND you could use the counter outputs to drive some LEDs. That way you always have visual feedback

[JovianPyx]

No second counter required. I believe that there are binary up-down counters. But really, with only 4 positions, a single button is probably sufficient. More than 4 might call for a second button. Using an up down counter would be more complex circuitry, however.

[fonik]

i used a 4017 counter and a DG412 switch. the circuit below has almost all bells and whistles, but one could easily leave them off.
http://modular.fonik.de/pdf/SeqSwitchV2.pdf