another question about complex switching!

[caress]

well i posted this just about a month ago:  http://www.diystompboxes.com/smfforum/index.php?topic=71275.0

and came up with this as a starting point:


i'm using the geofex article on cd4053 switching and the tone god's article on wicked switches as references.  plus the datasheets for all the chips.


some points about my schematic:
i'll be switching DIGITAL signals, which may or may not be important...
i'll be using either the cd4017 or cd4022 to switch between 8 signals.  i've only shown 3 since each cd4053 has 3 switches and i wanted to show it as simply as possible... the larger design has 3 cd4053s.
the power isn't added for any of the other chips yet.

some questions to start:
do i need the resistors/capacitors as shown in the geofex article on the cd4053?  i didn't show them again for simplicity... also, if i'm switching one side to ground, i surely wouuldn't need the passive components there, right?  are digital signals ac coupled?  will i still get clicks/pops without those external components?

i'm not totally sure how to wire up the cd4017/4022 yet.  would i tie pins 8, 13 and 15 to ground, then send the control signal from the cd4049 (pin 2) to pin 14?
is there a somewhat simple way to reverse the steps when the counter reaches 8 then again when it reaches 0?  like this 0 1 2 3 4 5 6 7 8 7 6 5 4 3 2 1 0 1 2 3 etc...
could i do this easier is i just programmed an eeprom?? then i would still need the control chips, just not the cd4053, right?

last one, if i wanted this whole shebang to control a numerical led display i could do more or less the same setup, yes?
if i split the control signal from the cd4049 to do that task, would that work?  whould i buffer it in some way?

ahhhh i know... so many questions... 

[R.G.]

Get a copy of "The CMOS Cookbook" by Lancaster.

i'll be switching DIGITAL signals, which may or may not be important...

It is important. Digital signals are as fussy as analog, but in different ways.

do i need the resistors/capacitors as shown in the geofex article on the cd4053? 

Those were to keep analog signals from popping. With Zero-to-Power supply digital signals, they're not needed.

are digital signals ac coupled? 

In general, no.

will i still get clicks/pops without those external components?

You won't get clicks and pops because of the lack of the Rs and Cs. But it's almost impossible to say whether you signal will be interference free. It depends entirely on what you digital signals are later interpreted as. Digital signals are very different from analog audio, and have no direct correlation. If, for instance, you are switching framed audio packets and switch in the middle of a packet, then you lose a packet from the stream and may have a pop or a dropout. If the signals are digital control signals, you can introduce unpredictable glitches if you switch away from a transition of the signal. If you want to guarantee that you don't contaminate the signals, you must switch the routing switches synchronously with the transitions of the digital signal, and at a frame boundary if it's framed up into packets.

i'm not totally sure how to wire up the cd4017/4022 yet.  would i tie pins 8, 13 and 15 to ground, then send the control signal from the cd4049 (pin 2) to pin 14?

Datasheet.

is there a somewhat simple way to reverse the steps when the counter reaches 8 then again when it reaches 0?  like this 0 1 2 3 4 5 6 7 8 7 6 5 4 3 2 1 0 1 2 3 etc...

Use an up/down counter chip instead of an up-only counter. Or use a walking-ring counter.

could i do this easier is i just programmed an eeprom??

Yes. Or a PIC.

then i would still need the control chips, just not the cd4053, right?

Yes.

last one, if i wanted this whole shebang to control a numerical led display i could do more or less the same setup, yes?

Yes; probably you'd need decoder/driver chips too.

if i split the control signal from the cd4049 to do that task, would that work? 

Too many options to say a simple yes or no.

whould i buffer it in some way?

Depends on the loading of the decoder/driver chips and the output drive capability of the counter at frequency. See the datasheets.
Better yet, get a copy of "The CMOS Cookbook" first.

[caress]

alright.  looks like i need to get that book...