Comments on: Rice Krispies Five-Digit Counter

By: Lev

Lev — Sat, 13 Mar 2010 20:01:09 +0000

Keith,

Yes, it would be wonderful if it could also count backwards.

I will look into your suggestion, it all sounds new to me. I’ve been looking into motor speed controllers in the last few days.

Could you contact me via email? I won’t take much of your time, it’s just that being new at this, I still have some questions even after doing research. It would be really helpful.

By: Keith Neufeld

Keith Neufeld — Thu, 11 Mar 2010 02:23:02 +0000

Lev, no, I’m sorry, but I haven’t got to the pickup winder.

Do you want something that would count both up and down; so if you had to unwind some loops it’d count them backward?

I’m thinking of something using a hall effect or optical sensor and actually building it with discrete TTL BCD counters and seven-segment drivers. I love the cachet of using old-school digital logic, but here I think it actually even makes sense.

By: Lev

Lev — Sat, 06 Mar 2010 00:12:04 +0000

Hello, Keith,

Did you ever write that post on your pickup winder? I don’t seem to find it.

I’m in the process of building a coil winder myself for guitar pickups and I’m a bit lost concerning the counter. I don’t have such a toy around here, just a few calculators but I would rather take a more elegant approach and build a 5 digit counter myself – I’ve spent the last few hours doing some research and your post got my most attention. Would you be willing to advise me on building this counter, please?

By: Paul Fisher

Paul Fisher — Tue, 26 Feb 2008 11:07:12 +0000

Keith,
I am trying to construct a cheap digital positional display. Imaging if you needed to know the position of something and you where tracking it so that every time it moved in one direction or the other the display informed you of its current position. I have achieved this with a 3 seven LED display using a home made ‘pulse wheel’ (encoder) which creates pulses in either direction via two photoerupters which are my inputs to a CMOS up/down counter circuit. I would prefer a cheap LCD solution and this thing needs to be battery powered so I’m concerned about battery life. I am certainly not an electronics boff. You may recommend that a PIC’s microcontroller is the best solution for this type of application (of which I know very little)

Regards
Paul
UK

By: Keith Neufeld

Keith Neufeld — Fri, 18 Jan 2008 15:08:02 +0000

Paul, that’s a good question. I’d be a lot better equipped to give you an answer if the counter chip weren’t hidden inside a blob of epoxy, and I could read the part number and look up a datasheet.

Looking back at my pictures, it’s not obvious to me whether there’s another line that could possibly be a count-down input — I’d have to look at it in real life again for a bit. But I kind of doubt that it has that functionality. And I doubt even more that anything I’d learn about this counter would apply directly toward another you might find.

If you can tell me a little more about your application (how low cost and how low power), I have a couple of other ideas that might work for you.

By: Paul Fisher

Paul Fisher — Fri, 18 Jan 2008 12:45:47 +0000

Keith,
I have a requirement for a low cost, low power LCD counter which needs to count down as well as up ie: from two separate inputs. Can a cheap counter like the one you’ve shown in your ‘Rice Krispies 5 digit counter’ article be configured to do this?

Regards
Paul
UK

By: Keith Neufeld

Keith Neufeld — Fri, 31 Aug 2007 01:09:40 +0000

What to count with it is actually an interesting question. When I was converting it, I actually had something in mind — turns of wire on a coil-winding machine, to make a custom pickup for my home-built solid-body electric viola. (That’s a whole ‘nother story for a whole ‘nother time, when I get it all finished.)

People have hacked old sewing machines to wind coils, and I figured I’d put a bump on the axle, trigger a microswitch or optointerruptor every time the axle turned, and count the turns with this counter. As it turns out, I’ve found it can only count about 2-3 steps per second, possibly by design.

Meanwhile, my wife is on the board of directors for the annual city festival, and needed a people-counter for the park gate she was staffing. I hot-glued a momentary-contact pushbutton to the case, wired up a plug cut off a cheap (and dead) cell-phone headset, and gave her a serviceable (but ugly) pushbutton counter.

I’d be happy to take suggestions for other things to count . . .

By: David Barak

David Barak — Wed, 29 Aug 2007 23:04:11 +0000

So what else besides steps are you going to count? Your audience wants to know! : )

By: Dave

Dave — Tue, 28 Aug 2007 18:55:46 +0000

The anisotropic strip on the LCD is technically known as an elastromeric connector, but usually referred to as a zebra strip. If you examine it closely under a strong magnifying glass or a low power microscope, you’ll see alternating bands of conductive and insulating material, usually something like graphite loaded rubber for the conductive material and unloaded rubber for the insulating material. The graphite loaded rubber gives that portion of the strip a darker colour. Thus, you have alternating light and dark bands, similar to what a zebra looks like.

Dave