Dedicated debouncer IC

Aug 12, 2020 79 Replies

Exactly, and that's what I want to avoid. Otherwise there are a number of ways to debounce using general-purpose parts.

I've used that and other techniques before.

Nothing specific at the moment. I just want to have a stock standalone solution for future applications.

Place the cheap micro, you will be able to use it for other stuff also

What debounce doesn't have instant action? I guess there are some where th e switch opens allowing an RC to rise which continues to get reset until it is done bouncing. The circuits I prefer follow the initial transition of the switch but lock out subsequent transitions until a time out. Best when done digitally in a single part of course. Analog solutions tend to be me ssy and have wide variations.

Heck, the switches themselves are best replaced with something else. Switc hes suck!

Rick C. - Get 1,000 miles of free Supercharging - Tesla referral code - https://ts.la/richard11209

It's possible to get resistor arrays for pullups, so the main 'debounce' requirement is just a bit of latching. Octal edge-triggered latches, with a 440 Hz (concert A pitch) clock, will get you eight debounced outputs with one 10-pin SIP pullup and a 74xC573, for under $0.10 per circuit. The clock, though, is an extra overhead.

Agreed, unless its for quite high volumes there is no point arguing a $1 micro against a free chip with extra parts for a "stock" solution.

small numbers from Farnell.

MK

For hobby-style products, there's a certain beauty in the three-cent Padauk gizmo, particularly since it's from Taiwan, which (so far) is outside the grasp of the CCP.

Squeaky Dave has a series of videos about how to get the open-source hardware and SDCC ("small device C compiler") toolchain working with the Padauk micros. A nice example of a community effort, for sure.

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(Dave is a lot easier to take when run at 1.75x speed on Youtube.)

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com

Switches suck!

I bet you prefer on-(touch)-screen keyboards for typing...

Mike.

2x, closed captions, speakers off :)

But then I dislike 99.9% of the electronics videos since I can read articles much faster than they can speak.

+1 - as those kids in web forums are fond of saying.

I'm typing on a keyboard with two broken keys. I have a new keyboard but taking a laptop apart is not always so simple.

Laptops suck!

Rick C. + Get 1,000 miles of free Supercharging + Tesla referral code - https://ts.la/richard11209

Why would you need debouncing anyway?

Feeding to a flip flop?

If feeding to a micro, then use sw solution

Anyway, a flip flop is more or less the same price as a cheap micro (western micros can be had for around 10 cent in volume)

Going into a uP port pin, sometimes people write elaborate debounce code. Usually, all you need to to is sample the level 10 times a second and accept what's there.

John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard

On a sunny day (Thu, 13 Aug 2020 04:37:21 -0700 (PDT)) it happened Ricketty C wrote in :

Laptops are great, for one thing those have a build in battery backup for if the mains fails.

I agree, except once in awhile Mike Harrison has something fun about his installation art, or Big Clive tears down some horrifically dangerous Chinese power supply or shower heater. All are better at 1.75x.

These ones walk you through using an unfamiliar toolchain with all sorts of gotchas along the way. And c'mon, a micro that costs 3 cents in onesies and has a standards-compliant C compiler! You've got to love that. I skipped through them, but there were several places where one could easily have wasted some hours before figuring it out. (Which we've all done, at least those of us who use micros.) The Flying Dutchman will deny this, of course, but he's full of BS. ;)

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com

They are the 0.1%, of course!

I'm sure you haven't forgotten Shahriar's The Signal Path, which is more than a talking head and *2 doesn't work for the audio nor for the captions :)

isn't Mike already at 1.75x ? :)

I'm not that big a Signal Path fan. Besides Shahriar having a classical Arabian Nights name (Scheherezade's husband), he's a smart guy who speaks well and talks about interesting stuff sometimes. He often seems to spend a lot of time on topics that I find old hat, though.

Once in a great while I'll watch one of Paul Carlson's repair videos, also at 1.75x. He finds some of the craziest old gear and restores it beautifully, for example an all-in-one bench gizmo from 1939, the 'Supreme Vedolyzer'. With a name like that it's gotta be good, right?

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com

In bursts, but not on average. Okay, maybe 1.5x for Mike, 1.75 for everyone else. I remember when he was a regular on SED, back in the Eeyore era.

Speaking of disappearances, DLUNU hasn't been seen here for months.

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com

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if you just want a quick look inside all kinds of weird old gear, this guy has plenty,

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From my 35 yo tips and tricks logbook: My goto debouncer is the MC14490. needs an external cap - useful when dealing with different ranges of bounce. Don't know about price comparison. For double throw switches, there is always the Set-Reset latch - a quad pack is 14043/14044 - cheap, quite effective. There is also the R-C approach followed by a hysterisis logic gate to square up the signal and clean up any voltage transients around the upper and lower thresholds. I like using either a 74HC14 or 40106. If you are running line into a micro, sw debounce is cheap and effective. Good luck

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