Need quick and dirty solution to floor my button

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1

Hey.

I wanted the circuit on the left.
However, because I used copper tape, I got the circuit on the right.

circuit-20251128-1012
circuit-20251128-10121868×964 32.5 KB

What I need is a floor function, such that my ~1.5v becomes zero.

I know I can use Opamps as a comparator.
Is there an easier way?

Link to falstad.

Edit.
I’m wondering if I should just swap the 1k pull up for a 500k. I think the only draw back is being current constrained. That may not matter.

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2

Hey @Pixmusix ,

Changing out your 1kΩ resistor for something larger, like a 100kΩ or 500kΩ, is the easiest way to do this that I can think of, as long as you are aware of the ‘softening’ effect this has on signal edges.

An Opamp solution is the technically correct option, but you can definitely get away without one.

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3

I have a 555 debouncer, which probably needs next to no current or anything like a sharp edge… I’ll give it a shot.

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4

Hi Pix
300Ω worth of copper tape. That is a lot of tape or you have high resistance joints and not using it properly.

If that circular thing is a lamp increasing the 1k to a much higher value might not be an option.

Op Amp or 555 you will not get to zeroV. The actual figure depends on the flavour of Op Amp. Some would be nearly your 1.5V (about 1.3V).

I think in the long term fixing your tape problem would be the best option. That 300Ω would be likely to change and even get higher in the future.
Cheers Bob

5

Lamps working. These are the buttons. Same project of working with a doll house.

I’ve spent a fair bit of time working on the tape. adding clean joins and layers to increase connectivity. In the end as the glue dries the resistance increases over the course of the next few days.

I’ll shoot a photo through of the tape. Maybe you have some advice.

6

Hi Pix
The doll house rings a bell. I think we have been down this hole before.
As I said previously. DO NOT rely on the glue to be conductive. You did this before and decided to go your own way and put up with it.

I think I provided a sketch previously. Solder the copper (non glued) sides of a connection then fold the top tape so it is glue down to carry on.

Fold the tape to change direction without cutting it in such a manner that it is glue down.

Solder a wire link across any joints made with glue in the way.

Dispense with tape and use wire then glue that down.

All I can think of. You have to solder any joins. Saying:: if you can’t do it properly don’t do it a all.
Cheers Bob
Quick and dirty enough ???

7

It was a really good idea
For some of the lamps I undid all the tape and re-did it with your advice.

For the light switches, I’m hoping to find another way without tearing up all my electrical wiring and re-doing it. I’ll start with changing that resistor and if that works I’ll take the win.

8

Hi Pix

It won’r really be a win.

In this business I have never seen the situation where 2 wrongs make a right. Just putting band aids on itt. It will always come back to bite you in the end.

I usually read most of your posts. You seem to be learning about hardware as you go. Am a bit disappointed here though.
Cheers Bob

9

Brutal but understandable.
I split my projects into two types: stuff that has to work and stuff that I’m gonna chuck out soon.
This doll house is not a forever project, my daughter will grow up soon and forget about it. :slight_smile:
Not every race needs to be a PB.

10

Hi Pix
The bit I was getting at but I hope won’t eventuate is that bad or poorer habits have a history of continuing into more important stuff.
Your choice
Cheers Bob

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11

Hi Pix

Why not ?? That way you get better and improve.
Cheers Bob

12

I guess I’m saying I have two options:
a) I can spend the next 8 hours fixing what I have got.
b) learn form this mistake, and spend the next 8 hours working on something new and hopefully better.

Its that principle of making 1000 pots instead of perfecting a single pot by remaking it 1000 times.

13

Hi Pix
Old philosopher me, I don’t think

I would go with option a)
That way you finish up with something that has a chance of working without any future hassles (like changing resistance of just glued joints). Or
Option b) which will still leave you with the unreliable glued joints and with the unknown in something new.

I can hear your little girl now. “Ddaaaaaddeeeeeee. The lights in my doll house don’t work”. I know which path I would prefer.

You usually learn from ALL mistakes. And normally don’t forget them. So making mistakes is really the best form of learning. As long as the $$$$ hold out.
Cheers Bob