new to csom stuff! help

[njkmonty]

i came across this which i would like to implement, but with some revisions if possible.
iv read that you can make the chip sequencial from 2 to 10  stages.
is there a way of counting in reverse by incorporating another momentary  switch and diodes with pin 15 of the chip? (i thought i saw something similar on web doing that )
also  is it possible to incorporate a 7 seg display with this circuit? does that need an extra chip do do that ? like 4026?

[~arph]

Nope,

If you need to drive a display and more then 4 outputs, you'd need at least three IC's at a quick glance.
Two CD4029 to do the decade up/down counting and one CD40110 for display driving.

[MrStab]

i'm no expert with CMOS, but i have considered similar things from time to time. if you want a reverse option, maybe you would be better off using an up-down counter like the 4029? (arnoud beat me to it!)

http://www.ti.com/lit/ds/symlink/cd4029b.pdf

i can't help much beyond that suggestion, sorry. hopefully someone else can!

[Seljer]

I assume you mean CMOS not CSOM

First point of reference is the datasheet: http://www.ti.com/lit/ds/symlink/cd4017b.pdf
The 4017 is a decade counter, i.e. it counts to 10. On the schematic drawn it's only counting to 6, when the pulse gets to the 7th output (pin 5) it's connected to the reset pin (pin 15) which makes the counter start over. Hook up the reset pin to whatever output and it'll only count up to that one.

If you wanted incrementing relays combined with an numerical indicator as well as the ability to go both up and down with just CMOS chips you'd probably have do use something like:
4029 - Presettable up/down counter, binary or BCD (binary coded decimal - 4 bits representing a number from 0 to 9 : 0000 0001 0010 0011 0100 etc...) <- to do the actual counting with "up" and "down" buttons
4028 - BCD to decimal (1-of-10) decoder <- hooked up to the 4029 to turn the BCD to 10 individual outputs for your relays  
4055 - BCD to 7-segment decoder/LCD driver <- hooked up to the 4029 to run the 7 segment display


The 4026 is also a decade counter but it has a built in decoder to drive a 7-segment display directly (so it's like the 4029+4055 together in one package), but you couldn't use it for the relays like on your schematic as it doesn't have non-decoded outputs.

Unless you really want the numerical display, it's probably less of a hassle to just have a separate LED for each of your outputs.

[~arph]

If you want to program you could do all of this with a PIC or an AVR (or an arduino for that matter)

to add to the above..  The 4029 can be set to decade counting. Yes, but I misunderstood, I thought it would act like the 4017, but setting it to decade just limits the counting to 0-9

[bluebunny]

I assume you mean CMOS not CSOM

Had me puzzled for a moment!  But then I've only had one coffee so far...  

BTW, you might find some useful pointers on synth DIY websites - lots of CMOS sequencing going on out there.

[njkmonty]

i went in store today and asked for cosm!?
ive been doing a lot of reading and trying to get my head around it.
ive come up with a draft plan but most likely not correct, i know i got to do as much as i can myself but if someone can keep nudging me in right direction that would be great

[commathe]

Your schematic won't work because you have misunderstood what Q1-4 do. More than one will be on at a time, like this:

1 = 0001
2 = 0010
3 = 0011
4 = 0100
5 = 0101
etc.

CMOS chips, particularly the 40xx and 45xx series ones are all designed do to DIGITAL things. Their outputs swing from +V to GND (1s and 0s).

What are you actually trying to do? If you can explain what you want the circuit to do maybe we can help you a little more.

[njkmonty]

2 momentary footswitches
one to bank up
other to bank down.
if possible be able to scroll though bank faster if momentary switch held down.
i would like to have minimum 4 separate relays can operate one at a time ,
ie scroll up or down by pushing the momentary switch to activate a relay in order, 1,2,3,4,1,2,3,4    or go the other way 3,2,1,4,3,2,1  etc
and if possible a 7 seg led display to indicate which relay activated , so in this example it would show only numbers 1 to 4
i hope that makes sense

[duck_arse]

if you only want to display "1, 2, 3, 4", you don't really need a decoder. find which of the seven display segments are ON for all four indications, and wire them on. once you've worked out your 1-of-4 up/down counter and relay driver, you can then switch the particular segments needed to show yr number, maybe needing a few diodes.

and your up/down switches will need de-bounce, and a clock signal for hold-down sequence.

[Seljer]

All the features you've listed make using only CMOS logic rather cumbersome and it would be much easier to just use a $3 PIC or Atmel micro-controller and be done with it (get a $20 Arduino that can be programed via regular USB if you've never used micro-controllers before)

So yeah, if you want a 7 seg display and only need a few numbers, you can use diodes to build a crude decoder powered directly from the individual outputs.  So for a number "2" for example you'd need 5 diodes to giver power to pins a,b,g,e and d on the display. The diodes need to be there so the current can't flow backwards when a different output is active and make the wrong segments light up. This isn't that bad if you only need to count from 1 to 4, you'd need a dozen or so diodes, gets a bit chaotic if you want all 10 numbers.

The issue with the 4029 binary counter is that it get complicated if you want to have it reset itself before it gets to 16 (or 10 if you have the decade pin enabled). Making it reset to 0 when it before gets to the top end isn't that hard, just use the preset enable pin with the preset/jam inputs to zero everything out prematurely. But you have to make it work appropriately when going downwards as which would surely add on another 2 or 3 chips of AND/OR gates or something.

Right now I'm thinking it may be easier to make this using a bidirectional shift register. Or maybe directly out of a bunch of flip flops. Or just go for the microcontroller  

[armdnrdy]

This is a variation of the circuit that I PM'd you last night.



It uses a 4066 for 4 channels. If you want more than four channels you will have to change IC3 to a different IC. (4051 for 8 channels)

This will give you the capability to move between channels (up and down) by pressing either momentary footswitch.
If either footswitch is "held down", within about a second, the channels will auto scan up or down until you let off of the footswitch.

As mentioned by Seljer, this circuit is a bit "cumbersome" but.......you are using relays, and two footswitches, so I would imagine that you had a larger enclosure in mind.

My advise to you....breadboard this before you commit to a build.

The front end of the circuit is verified....but the addition of the 4511 and 7 segment display is not. I believe it will work.