Almost OT: Pushbutton switch latching

[Tony Duell]

> 
> On 5 Dec 2007 at 16:35, Mr Ian Primus wrote:
> 
> > The main thing I'm trying to achieve is simplicity.
> > Nothing fancy. No PIC's, no microcontrollers, etc. I
> > initially thought of using flip flops and a bunch of
> > inverters to reset all the non-selected flip flop, but
> > couldn't work out in my head a good way to do it... I
> > hadn't taken switch debouncing into the equation - but
> > aren't flip flops commonly used to debounce switches
> > anyway?
> 
> ...or a 0-7 BCD switch connected to a demux chip?  Small, direct 
> readout.  

Or a normal rotary switch and a bunch of pull up/down resistors (I don't 
know if the enable lines are to be active high or active low)? Even more 
direct. For that matter, what about a bank of mechancially-interlocked 
buttons (I think you can still get such swtiches and the bracketry to 
interlock them).

-tony