start stop rest with single button

[trayd]

I'm building one of the example count down timers found on the net using 555 and 4029 counters and all the examples use two seperate buttons to control the start/stop and reset functions. Is it possible to use a single button which would toggle between start and stop for each brief press of the button, but would activiate the reset for a longer press of the button? I would like the countdown timer to act more like a basic stopwatch.

 

[HarveyH42]

Use a debounced pushbutton on the clock pin of a 4017, the 4th output of the 4017 would go to the reset pin. You didn't post a schematic, so can't tell you where to put the three outputs for s/s/r...

 

[windozeuser]

You could use a bistable flip-flop for start/stop operations, for the reset I'm not quite sure right at this moment. You basically need to latch, unlatch, and actually for the long holding you would need some type of counter, or capactior time delay? A second switch would be much easier and cost effective. Of course I would love to hear the other peoples solutions.

 

[muszerjav]

I offer this for You.
**broken link removed**
Choose the: Alternating On/Off switch!