[HN Gopher] 555 Timer Circuits
___________________________________________________________________
555 Timer Circuits
Author : okl
Score : 255 points
Date : 2024-10-17 18:30 UTC (3 days ago)
(HTM) web link (www.555-timer-circuits.com)
(TXT) w3m dump (www.555-timer-circuits.com)
| tahoupt wrote:
| Shout out to Forest M Mims III, the OG 555 circuit
| guru.https://en.wikipedia.org/wiki/Forrest_Mims
| stonethrowaway wrote:
| He's working on a new book that attempts to disprove evolution
| or at least show cases to the contrary, advocating for a grand
| design as a primary mechanism instead. Curious to read it, I'm
| hopeful he will release it.
| Mistletoe wrote:
| Also a global warming denier. I'd love to see him explain how
| this is wrong?
|
| https://climate.nasa.gov/vital-signs/global-
| temperature/?int...
| stonethrowaway wrote:
| Your comment appears grey to me so I assume someone
| downvoted you? How strange.
|
| At any rate, I do own his books on electronics as a kind of
| an amusing look into the history of how electronics were
| taught, but I do find it to be a positive thing in the
| world to have curious individuals like himself.
|
| People from all walks of life believe all sorts of kooky
| shit. That's the spice of it I suppose.
| nickpsecurity wrote:
| You might enjoy this article which lists all the articles of
| faith evolutionists believe in:
|
| https://answersingenesis.org/theory-of-evolution/12-the-
| basi...
|
| My biggest critiques are that it consistently fails its
| predictions. You'd see an endless stream of intermediate
| forms going in so many directions. Instead, we saw few if
| any, nature organized more hierarchically, and organisms just
| appear out of thin air after extinctions (eg Cambrian
| Explosion). Instead of falsification, scientists keep making
| excuses for it like it is a religion that can't be wrong.
|
| I'll add that humans have observed creatures, in their areas
| and in captivity, for a long time. We haven't seen the
| chickens start giving birth to different animals. I'm
| grateful the fire ants and poisonous spiders we're dodging
| haven't turned into something more effective. Dumb evolution
| would have a crazy number of adaptation streams happening,
| many attempts per species, to create all the life we see.
| Instead, we see exactly zero movement from one kind of animal
| to another with changes only happening within kinds.
|
| Whereas, studies of creation itself have proven the opposite.
| Everything from our non-life experiments to evolutionary
| algorithms show a creator who fine tunes is necessary. The
| universe itself has many constants that never change, they
| work together in precise ways, all has perfect reliability,
| and life on Earth depends on most of them. Complexity of most
| of biology is such that we're incapable of manufacturing it.
| (See a lung vs a respirator.) It only gets more and more
| impossible over time the more we learned.
|
| On time scales (X is millions of years old), they seem to
| assume the Earth didn't change much at all over a long period
| of time. A specific thing changes at rate X. They'll roll the
| clock back that much until they hit a point in their theory.
| Both human literature (esp Genesis) and the fossil record
| show catastrophes with huge effects on the Earth. It probably
| went through many changes. So, all time estimates that make
| that assumption are faith-based, likely-incorrect beliefs no
| matter how many textbooks they end up in. There is a minority
| studying Catastrophism or something like that to understand
| their effect.
|
| Finally, godless science that broke from Christian
| scientists, like Newton and Pascal, all backed David Hume
| saying only material, observable things exist. Nothing else
| is ever allowed in scientific theory. A faith-based, unproven
| belief. While still making godless and materialism axiomatic,
| the same scientists tell us of a world outside our universe,
| exceeding the laws of physics, and maybe even having effects
| on observed phenomenon. Instead of things with evidence (eg
| Bible), they've shifted to purely-imaginary constructs
| outside the universe to support their claims which themselves
| contradict the Hume foundation they demand of us. They do it
| while denying the logical implications of the complexity and
| fine-tuning we've observed.
|
| Those are some examples of counters to mainstream creation,
| like evolution and long timescales, being a pile of faith-
| based dogma that continues to fail in scientific experiments,
| historical writings, complexity theory, and global
| observations by laypeople. Outside of minor adaptation,
| evolution theory is provably false which leaves God as the
| primary hypothesis. From there, we consider whichever God
| claim has the most evidence and impact. That's Jesus Christ.
| :)
| buildsjets wrote:
| Built many a 555 timer circuit back in the day! But in modern
| times, I can get an ATMega328p already attached to a PC board for
| $2.50 and load code on it to do whatever I want, including blink
| a red LED.
| tdeck wrote:
| Not only are cheap microcontrollers often an easier choice for
| things the NE555 might be used for, they often draw far less
| power as well. I personally prefer to use an even smaller and
| cheaper micro like the ATTiny13A. It's also worth noting that
| your traditional 555 timers don't like to run below 5V, for
| that you'll need something like an LMC555. If you're building
| up a parts inventory, it often makes sense to have a bunch of
| very cheap micros rather than special purpose parts.
| Joel_Mckay wrote:
| Could always use a 555 as a charge pump for your micro power
| mcu too.
|
| Indeed, a small $0.23 mcu may have its own internal RC
| oscillator, or even a MEMS based resonator on a PLL. =3
| dragontamer wrote:
| The main advantage of 555 timer is that it is configured with
| a resistor/capacitor kit. No computer or programming
| required.
|
| Microcontrollers obviously have more than 1 bit of memory +
| 2x analog comparators + one 33% / 66% voltage divider (which
| is all a 555 timer truly is).
|
| What is surprising however is how flexible 1 bit of memory +
| 2x analog comparators + one 33% / 66% voltage divider
| tdeck wrote:
| Another way of looking at it is the 555 is useless without
| multiple extra parts, where as most MCUs can operate with
| only a bypass cap (and even that is often optional in
| practice). But you do have to buy a programmer ($5 these
| days) and get comfortable with firmware, which puts some
| analog folks off. I'll admit that there is a certain
| elegance and appeal to using only parts you fully
| understand and nothing extraneous.
| dragontamer wrote:
| Even if you have a microcontroller, there are simple
| situations where the 555 can come in handy.
|
| For example, switch debouncer could be solved in code,
| resistor+capacitor or other methods. But you know what's
| one of the best performing switch debouncers?
|
| 1-bit of memory with an analog comparator. Aka: a 555
| Timer.
|
| > 555 is useless without multiple extra parts
|
| Not needed for bistable multi vibrator (aka: just a flip
| flop mode). Which happens to be the debouncer circuit.
| tdeck wrote:
| I'm curious what the circumstances are where that would
| be worth the extra BOM count if you're already feeding
| the input into a microcontroller. Needing to detect
| extremely short pulses where you can't spare a pin
| interrupt? Something else I can't think of?
| dragontamer wrote:
| Black Box engineering.
|
| You can add the 555 Timer to an already completed design
| if it is later discovered that debouncing was an unsolved
| problem.
|
| I don't think it is always appropriate to assume that
| code can be rewritten (or rearchitected) to fit your
| needs. Sometimes its easier to solve problems with a
| touch of extra external hardware.
| doe_eyes wrote:
| Except, it's not an advantage in any practical sense.
| Programmers cost pennies, toolchains are free and easy to
| use, and there are ample examples for simple tasks such as
| "toggle a pin in a particular way". The overall learning
| curve is almost certainly less steep than the learning
| curve for all the modes and quirks of the 555.
|
| What matters in production is that a 555-based circuit will
| use more power, that it's four components to source and
| install instead of one, and so on. Don't get me wrong, I
| like the 555, just like I like vacuum tubes, but it's
| nearly as dead.
| lightedman wrote:
| "that it's four components to source and install instead
| of one,"
|
| The ATMega needs about ten components to get properly
| operational for programming vs a simple 555 timer
| circuit. Oh, and then you also need the programmer and
| toolchain for making the code.
|
| Or you can just use some basic math and thrown down
| native hardware to do the job. One of the biggest off-
| road lighting manufacturers on the planet does exactly
| this with 555 timers.
|
| I manufacture lighting controls of various sorts as my
| current profession.
| askvictor wrote:
| Hell, you can get an ESP32 with wifi and bluetooth for that
| price.
| omani wrote:
| why would you buy an ATMega328p for that price if you can get
| an ESP32 with wifi/ble and awesome rust support? ;)
| kilpikaarna wrote:
| Can you actually get a genuine Atmel for that price? Bottom-
| rung Chinese Arduino clones sure, but you better order 10 of
| them because they will randomly stop working as you're
| tinkering with your circuit.
| tdeck wrote:
| Here's my tip for the 555 timer: Learn what's inside it! As you
| can see on the "Inside the 555" page, there are fewer than 10
| functional components inside and three of them are resistors.
|
| For some reason I always struggled to remember the different
| operating mode configurations, what they are called, and how to
| set them up. But one day I was trying to build a specific thing
| and decided to sit down and actually understand the 555. To my
| surprise, it's really simple in operation and requires relatively
| little electronics theory to understand and derive the different
| configurations yourself. Once I did that, I haven't forgotten it
| and I can come up with more creative uses for the 555.
| 082349872349872 wrote:
| You might be interested in http://www.designinganalogchips.com
| ...
| tdeck wrote:
| Thanks, I hadn't heard of this book and will definitely check
| it out!
| gus_massa wrote:
| Another link about the internal pars of the 555
| https://www.righto.com/2016/04/teardown-of-cmos-555-timer-ch...
| Stratoscope wrote:
| The Evil Mad Scientist kits are a great way to learn what's
| inside it. They are faithful replicas of the internal 555
| circuitry, built with discrete transistors and resistors.
|
| You mentioned only ten functional components inside it, but if
| you look at individual transistors and resistors, there are
| quite a few more.
|
| Here is the through-hole component version:
|
| https://shop.evilmadscientist.com/productsmenu/652
|
| And a surface mount device version:
|
| https://shop.evilmadscientist.com/productsmenu/922
|
| I built the through-hole version, and it worked the first time
| I wired up a circuit around it.
|
| Highly recommended!
| NikkiA wrote:
| '10' would be counting the comparator and 2 op-amps as 3
| components, the replicas you're pointing at break those out
| to discretes too, because once you've started down that road,
| why wouldn't you?
| JKCalhoun wrote:
| I love the circuits on this site (1). Kind of quirky layout
| (pretty sure the parent page uses "frames") but has fifty 555
| circuits as well as 100+ transistor circuits, etc on the site.
| Def a labor of love. (Buy the CD, ha ha.)
|
| 1)
| https://www.talkingelectronics.com/projects/50%20-%20555%20C...
| doe_eyes wrote:
| In some respects, it's a testament to how much the world of
| electronics has changed over the past ~25 years. It used to be
| that 555 was this Swiss-army-knife IC that you had to learn
| about. Multiple people published entire books about it!
|
| Today, it's essentially obsolete. You're quite unlikely to find
| it in any competently-done commercial designs. Every analog trick
| you can do with it can be done more cheaply, more reliably, with
| better power efficiency, and with fewer external components using
| a modern MCU.
|
| It's not that analog is dead, but it's solving different problems
| now. Including how to keep ultra-high-speed digital signals
| usable within the footprint of a PCB - which wasn't that much of
| a consideration in the golden days of the 555.
| theamk wrote:
| There is still at least one niche for it: very simple circuits
| which requires >5v. Using 555 lets you skip the regulator and
| drivers.
|
| But even there, it's high Iq limits its applicability.
| 01100011 wrote:
| I'd guess that a 555 is also tougher than a microcontroller.
| I'm putting together an HV supply and thought about using a
| microcontroller but opted for a 555-based oscillator. Either
| one won't survive HV but I think the 555 will handle stray
| charges better.
| K0balt wrote:
| Modern mucus are surprisingly fault tolerant. Just saying.
| It's not like the bad old days where if you sneezed at a
| cmos chip it would probably be fried. I'm not sure how that
| stacks up to a 555 though.
| 01100011 wrote:
| My mucus is about as fault tolerant as it ever has been.
| Sometimes it gets really thick if the weather is dry or
| I'm sick, but otherwise I haven't noticed any difference.
| I find that drinking water helps.
| dsv3099i wrote:
| I think it's more that the 555 is basically the heart of
| hysteretic controller in a box, but it doesn't have the other
| stuff you need.
|
| https://en.wikipedia.org/wiki/Bang-bang_control
|
| There's still plenty of analog control out there, it's just all
| hidden away as parts can integrate the sensor, controller and
| actuator, all in one magic IC. And it can definitely be lower
| power and cheaper, in volume. The main weakness is the NRE is
| higher than the typical MCU project so it's not really seen in
| low volume or hobby level stuff.
| lightedman wrote:
| "You're quite unlikely to find it in any competently-done
| commercial designs."
|
| You'll find them in tons of commercial designs - your modern
| headlights (which I manufacture) and off-road lights use them
| in droves. Short-timed lighting like automatic UVC
| sterilization lighting and such also still relies heavily upon
| a 555 timer just to act as the on/off switch for the power
| driver pushing the LEDs.
| amluto wrote:
| Now I'm curious: what is the role of the 555 timer in a
| headlight?
|
| I have a bit of a pet peeve about car lights (usually
| exterior lights that aren't the headlights) that are visibly
| pulsed. They can be distracting. I think they should all be
| designed to operate either at silly frequencies that are
| genuinely undetectable by human eyes (30kHz?) or to genuinely
| operate at DC.
| lightedman wrote:
| "what is the role of the 555 timer in a headlight?"
|
| Newer headlights use the 555 timer as a quick comparator to
| turn off the headlight when the corresponding turn signal
| is activated, and control the turn signal simultaneously.
| amluto wrote:
| Huh, I always imagined that newer cars would have a
| single CAN link to an ECU [0] in back, and that ECU would
| control all the lights near it. 555 timers may be cheap
| and robust, but monster wiring harnesses are not so
| cheap.
|
| [0] Why do cars have special names for microcontrollers?
| lightedman wrote:
| "but monster wiring harnesses are not so cheap."
|
| They aren't needed when the lighting is LED. The wiring
| harnesses going to more modern headlights are quite thin.
|
| "I always imagined that newer cars would have a single
| CAN link to an ECU [0] in back, and that ECU would
| control all the lights near it."
|
| They do but some are moving away because of the total
| lack of security and ability to compromise the CAN bus
| through the headlights to steal vehicles - read
| https://www.autoblog.com/news/vehicle-headlight-can-bus-
| inje... for what's going on there. They're too cheap to
| actually spend the money on real hardening so they're
| moving back to pure hardware control in many cases.
| daghamm wrote:
| Is this for a western car maker?
|
| Haven't seen 555 in a commercial product with modern
| design for a long long time.
| roelschroeven wrote:
| > to turn off the headlight when the corresponding turn
| signal is activated
|
| Wait what? Why is a headlight influenced by a turn
| signal??
|
| I realize that American brake lights and turn signals are
| more intertwined than is reasonable, I've seen the
| Technology Connections Youtube video. Are you telling me
| something similar is going on with headlights?
| vicnov wrote:
| Can you recommend books/courses that cover this new approach
| you're talking about?
| georgeburdell wrote:
| Yep, came to this realization awhile ago, about the superiority
| of digital in many cases, when I had an amplifier project with
| a dizzying number of requirements and a very large dynamic
| range and (log) linearity needed. Ended up using a few ranges
| of ADC's, doing the required mathematical transform on a MCU,
| then outputting the required voltage with a DAC. The previous
| gen was some fairly complex circuit designed by a smart analog
| guy and still wasn't nearly as performant
| irunmyownemail wrote:
| There's still room for synchro and servo theory I learned in
| the Navy but I really like the digital world a lot, so
| flexible.
| buescher wrote:
| Even in jellybean analog, almost everything you can do with a
| 555 timer you can do with a quad comparator. And more. Over a
| bigger voltage range, too. It's usually a design smell to see a
| 555 used for anything in a professional design, even from
| before the tiny mcu era.
|
| It makes a nifty missing pulse detector, though.
| iwaztomack wrote:
| Its kind of interesting: the 555 is such _horrible_ timer. It
| can't do a 50% duty cycle without extra BOM parts, even more
| parts to make a real PWM out of it, and it has terrible
| temperature and voltage stability. But somehow it persists.
| II2II wrote:
| Plenty of people are commenting on how modern microcontrollers
| are better than the 555. I agree, with a caveat: the 555 is a
| great learning tool. It is complex enough to be interesting, yet
| simple enough to be well understood. It is easy to clip an
| oscilloscope to it's pins to have a visual representation of how
| its inputs affects its outputs. It is a stepping stone that helps
| people learn how to build more complex circuits. Much as some
| software developers have to understand assembly language to build
| the most fundamental bits of software (e.g. compilers), some
| people have need to understand electronics to build the most
| fundamental bits of hardware.
| FooBarBizBazz wrote:
| I always found DACs/IO to be the limiting thing with
| microcontrollers. That and latency in general. When you were
| doing analog stuff with op-amps, yeah, you were setting
| yourself up for other problems like thermal drift, but there
| was never any worry that you were going to run out of capacity
| like you would switching tasks on a microcontroller, and
| latency was negligible. Plus there weren't many wires and you
| could see it on a scope. It was all satisfyingly immediate. I
| wonder what kind of cheap and ubiquitous DSPs(?) people use for
| that kind of niche nowadays, to do it digitally(?). Do they
| string DACs together on a bus somehow? How do you get, say,
| signals flowing around at a couple hundred kHz sample rates,
| with nice dataflow parallelism -- and then get those signals
| out to actuators, without much latency -- in that world? Like,
| what would you use to mix a bunch of audio and run some IIR
| filters with 20ns latency? Or control, say, four motors with, I
| dunno, 1 kHz bandwidth? I get this feeling that DACs remain a
| bottleneck and you're rapidly looking at expensive stuff to do
| that with a microcontroller, but maybe I'm wrong; I don't do
| this stuff.
| Neywiny wrote:
| As an FPGA developer: much agreed. We know exactly what's
| happening every clock cycle (or at least can), and often are
| able to have extremely deterministic computation. You can do
| this on micros, but anything with good performance will have
| some caching, maybe context switching, etc. The polarfire SoC
| marketing has a graph showing either determinism or
| performance (I can dig it up if interested). In FPGA land, we
| define the pipelining such that we get both. I usually go out
| to an RFIC then stop caring, but you can calculate the
| latencies the as well.
| nuancebydefault wrote:
| Fpga's have the best of both worlds!
| racked wrote:
| I'm not an expert by any definition of the term, but a book
| on programming for the Raspberry Pi Pico with Micropython
| recommends the MCP3008 ADC.
| 6SixTy wrote:
| Only problem is that an oscilloscope isn't accessible to
| beginners. It's a specialist piece of equipment that takes time
| to learn how to use, and are furiously expensive at best for
| someone who doesn't know they might like electronics to buy.
| That's fundamentally why people are lauding the benefits of
| microcontrollers, figuring out what's wrong with one doesn't
| require an O-scope.
| nuancebydefault wrote:
| Indeed. An intuitive, easy to use oscilloscope needs at least
| to be digital and hence expensive. An alternative is using an
| electronics workbench simulator, but then again you might as
| well go fully digital.
|
| When circuits become larger than trivial, the analog way is
| noise and temperature sensitive, you will spend a lot of time
| on tweaking those aspects by themselves.
| II2II wrote:
| That really depends upon the context. Many learn electronics
| in a classroom environment. Even for those who learn
| electronics independently, it has been possible to get new
| oscilloscopes that work at audio frequencies for well under
| $100 for many years. It looks like scopes that operate upto
| 20 MHz have been available for under $100 for a couple of
| years. They aren't great, but they are still powerful tools
| for learning.
|
| And while scopes do take time to learn, learning about scopes
| themselves will convey a lot of fundamental information about
| electronics. I also wouldn't underestimate the difficulty in
| learning how to use microcontrollers. While using something
| like Arduino (boards, shields, development tools, and
| libraries) may be straight forward, the learning curve rises
| steeply as soon as you try to do anything truly
| independently. More steeply, I would suggest, than learning
| how to use an osilloscope. Besides, most of those development
| boards cost a lot more than a bare chip.
| reader9274 wrote:
| Might be interested to check out this legendary book:
| https://en.m.wikipedia.org/wiki/The_Art_of_Electronics
| cpldcpu wrote:
| Well, you can also build microprocessors out of them:
|
| https://hackaday.io/project/182915-555enabled-microprocessor
| lmpdev wrote:
| We sell kits with plenty of 555 timers (including some listed
| here)
|
| It's a shame that Arduino has effectively truncated kids learning
| with a full MCU as the "building block" of their learning
|
| I see it also bite them in the arse with wasteful solutions.
| Often a BJT or power fet is all they need (say for a basic relay
| trigger). But if they aren't presented with a shiny arduino
| compatible module explicitly designed for what they want, they
| get nervous
|
| About half the kids I see make the intellectual jump, half end up
| not coming back
|
| I do wish kids were taught basic soldering, it would make the
| learning process a lot less worrisome
|
| The 555 and LM741 are still supreme learning tools. They are even
| simple enough to breadboard out with BJTs and analogue
| components. I've only seen a few extremely hardcore guys bother
| to conceptualise under the hood that deeply
| doe_eyes wrote:
| > It's a shame that Arduino has effectively truncated kids
| learning with a full MCU as the "building block" of their
| learning
|
| Why? I think the vast majority of hobbyists used the 555 as a
| "black-box" chip. They now have a more intuitive, cheaper, and
| more power-efficient way of doing the same thing.
|
| Pre-Arduino, learning electronics wasn't more profound. It was
| just _less accessible_. Nowadays, you have the same number of
| determined and talented hobbyists who eventually master some of
| the more arcane topics. You also have more people who learn
| just enough to get their art project done, and it 's easier
| than it used to be... but why is that a bad thing?
|
| There's a temptation to demand that others do things the hard
| way just because we had to. But is it healthy? I don't lament
| the demise of the 555 any more than I lament that the youth no
| longer knows how to put shoes on a horse.
| giantrobot wrote:
| > There's a temptation to demand that others do things the
| hard way just because we had to. But is it healthy? I don't
| lament the demise of the 555 any more than I lament that the
| youth no longer knows how to put shoes on a horse.
|
| I agree with both you and the GP. Arduinos tend to make
| goofing around with electronics more accessible to more
| people. At the same time a lot of projects could be built
| very simply with just a couple timer chips. It's unfortunate
| people reach for a relatively complex solution (Arduino etc)
| to what's ultimately a simple problem. They would benefit a
| great deal from just knowing a blinking light can be made
| very simply with a simple circuit.
| ryandrake wrote:
| I liken it to people who reach for kubernets and docker and
| microservices and cloud infrastructure when a simple LAMP
| stack running on a single box will do. And people who reach
| for a hosted javascript app when a native one that doesn't
| require internet will do. They're not wrong, just
| unnecessarily complicating things because they learned how
| to do it the complicated way.
| giantrobot wrote:
| I get what you're saying and I don't disagree but I don't
| know if the analogy works.
|
| An Arduino is very approachable in that you can just plug
| it into a USB port and tell it to blink a light following
| a very simple tutorial. No breadboards even, just plug in
| a device and open a program. Under the hood the Arduino
| is very complex but for the end user it's very simple.
|
| A lot of Arduino compatible modules are also simple for
| the end user despite being very complex under the hood.
|
| The simplicity for the end user is I think the biggest
| attraction for the Arduino. In your K8s analogy, it is
| not simple for the end user. Someone may build some K8s
| monstrosity because that's what a tutorial or bootcamp
| taught but it's very obviously complex. The hosted
| JavaScript app is a better Arduino analogy, it's a
| complex solution under the hood but presents a relatively
| simple user experience.
| kmbfjr wrote:
| You raise an interesting issue to which I offer just ONE
| counterpoint. That is, a 555 circuit often requires external
| circuits that involve useful theory beyond basic circuits.
|
| I'm thinking RC timing and voltage dividers. These have
| practical application. Would it ever get used elsewhere? That
| is where my thinking merges to yours.
|
| Forty years from when I started that journey, not sure it
| can't be learned from a wiki.
| 15155 wrote:
| Voltage dividers are still commonly used in MCU-laden
| designs, as are RC timing circuits.
|
| (The power supply sitting next to that MCU has a divider-
| based feedback loop, usually.)
|
| These possibly can't be learned from a wiki, but they can
| absolutely be learned from the Art of Electronics for a low
| price.
| wkjagt wrote:
| A potentiometer is a simple voltage divider, and I think
| often used as an input to the ADC of an MCU, as a means
| of turning some some value up or down.
| K0balt wrote:
| Starting in electronics 47 years ago, digital electronics
| clicked for me in a way that analog didn't. My early analog
| circuits often used digital components to create clear
| deterministic behavior. The 7400 was my do everything black
| box and the 555 was the timer of choice when it became
| available.
|
| But I always dreamed of a digital future. When I was very
| young, microprocessors fascinated but intimidated me with
| their need for special support chips, and I would design 4
| bit computers I couldn't afford to build using 7400 logic and
| 4 bit SRAM.
|
| For a while, I strayed from the path and learned to program
| on my C2-8P computer that my brother and I bought. By middle
| school, I was more or less distracted, and came back to
| technology later with the TS1000 and later the c64.
| Eventually, the AT2323 brought me back into electronics with
| MCUs, and I found it was the world I always fantasised about
| as a 7 year old kid designing 4 bit ALUs. I don't know why I
| missed out on the early PIC days, but I think it was girls,
| cars, and LSD, mostly lol.
|
| Anyway, since then, I'll unashamedly put a 6 pin mcu in just
| to flash a light, but I'll make it flash in a better way, so
| that it grabs your attention when it is starting or stopping
| flashing, for example. Or it will flash in a way that
| communicates just a little more about what it's telling you.
| I find with MCUs your stuff can be just a little bit better
| in a thousand subtle ways, and despite 10000x the parts
| count, more reliable and resistant to environmental factors.
| With modern mixed-signal MCUs that can drive 60ma on a GPIO,
| most things can boil down to a single chip with a few
| external parts.
|
| Then you get to stuff like the esp32 platform, where for $1
| you get a single chip solution that puts my first 486 PC to
| shame playing DOOM, even while bit-banging the video output.
| There's no point in using something less capable unless you
| are making more than a thousand units, in which case you can
| still end up with a $0.10 risc-V running a respectable 24 mhz
| at 32 bits, with more flash and ram than my old C2-8P.
| le-mark wrote:
| > By middle school, I was more or less distracted, and came
| back to technology later
|
| Lol this also happened to me, I wonder how common this is?
| nuancebydefault wrote:
| The esp32 is amazing. It has a flexible IP block that can
| create complex patterns on gpio without the cpu needing to
| bit bang. You can use one core for the ip stack and the
| other for example for running micropython scripts. Its the
| 555 of today, a million times.
| masto wrote:
| > Pre-Arduino, learning electronics wasn't more profound. It
| was just less accessible.
|
| This absolutely matches my experience. I was very interested
| in electronics growing up in the 80s. I took everything apart
| (occasionally without breaking it), I had those spring
| terminal "200 in 1" kits, a crappy soldering iron, and tons
| of enthusiasm and energy to channel into it. But I very
| quickly hit a wall trying to understand analog circuits, and
| I gave up (and redirected my interest to computers).
|
| Some of it could be the limited information I had access to,
| in a small town, pre-Internet. There was a lot of math, and
| this was when I was like 8-10 years old, so it was way over
| my head. But I tried several times over the following decades
| to get back into it, and I just couldn't find a way in that
| connected with me.
|
| The point of all of this is that in 2012 I stumbled across an
| Arduino kit and everything changed. Now I could apply the
| digital logic and programming concepts I understood to make
| things that did stuff. I rediscovered my interest in
| electronics, and the part that's most relevant here is that
| because it was accessible and fun, it gave me an on ramp to
| start to explore the analog world a bit more. The concepts
| began to make sense and build on each other as I developed an
| intuition for how they worked, and now I feel reasonably
| comfortable with analog circuits.
|
| So I don't see it so much as nobody is going to learn other
| things because they can just throw a MCU at it, I think it's
| a great way to get started and then go on to develop a more
| thorough understanding of electronics (if that's your thing).
| bityard wrote:
| ... Are you me? I followed essentially the exact same path.
|
| I got into electronics (and to some degree, computers) as a
| means to do something cool. I don't have the drive to
| memorize data sheets spend hours playing component golf. I
| just want my circuit to work, even if it's not the most
| efficient way possible to do it.
| nuancebydefault wrote:
| I started experimenting with electronics long pre-arduino
| as well. I studied electronics later. But still somehow I
| never got my brain quite wrapped around analog electronics,
| beyond the basics and the things following pure logic. I
| would still break my brain on a bi-stable multivibrator
| using analog components. I guess I am missing some gen.
|
| That said, some analog principles are still needed in the
| back of your mind when making digital stuff. Input
| impedance, rise time, ripple etc.
| atoav wrote:
| I grew up with Arduinos, never used 555 because it draws too
| much current for what it is doing. I get how it once was a
| popular thing, but if I need a simple delay circuit or simple
| logic that needs to e precise I do it discretev if ir needs to
| be more complex there is any number of MCUs.
|
| I was 100% self thought and teach electronics in art university
| now. And I have to say I can't really confirm your suspicions
| about "the kids", sure many stay at the module level (totally
| okay, they study arts not electronics), but many don't. I had a
| student who over the course of 2 years built a brain wave
| reading circuit with a specialized instrumentation amplifier
| IC, to filter out grid EMF she built an opamp based notch
| filter and that woman had nearly no help from me and no prior
| education in the field. That analog stuff isn't going away
| anytime soon.
| dsv3099i wrote:
| It is a bit unfair though as one is comparing new MCU to
| ancient parts. For example the TLV9301 is a updated version
| on the 741 and is superior in basically every possible spec,
| but people still use the 741 out of habit. And if you need a
| lower power discrete timer, the 555 is not the best way to do
| it in 2024. There are a huge number of options.
|
| For art projects I totally get using a MCU. You're probably
| only making one and the product is the art. The engineering
| just gets in the way so minimizing man hours, which includes
| the time to learn to do the thing, is critical. It will be
| tough to beat a MCU on that metric.
| atoav wrote:
| That is what I meant: the 555 is a habitual option by
| people who grew up with it. The arduino can be an habitual
| option by people who grew up with that.
|
| Not every project is mass produced or must be highly
| optimized when it comes to size, cost or power consumption.
| People use what they know, and what they know depends on
| when they grew into it.
| 6SixTy wrote:
| Arduino is very much less about the board itself, and
| more of a software framework. Every single "Arduino
| compatible" board beyond the standard Uno or Micro have a
| bunch of macros essentially just telling the compiler
| what the standard Arduino pin definitions go where. That
| even extends to boards like the 2560, since I know the
| port registers and the silk screening on that board are
| completely different.
| cellularmitosis wrote:
| This tension between two paths, the microcontroller path vs the
| analog path, there is a bit of an analog to this in the game
| Factorio. You can use combinators to build sophisticated
| circuits (the microcontroller path), but there's also a lot you
| can do with just a few red wires (the analog path).
| the__alchemist wrote:
| Why Arduinos in particular? We're in an era where you can
| choose any MCU (ARM, Espressif, RiscV e tc), pick a language
| you like within limits (C, C++, Rust, Python (sort of)), and
| make it happen. Open KiCad, design a PCB, and have it arrive
| from Shenzhen in 10 days. Or, order a dev board, and attach
| additional circuits to it. (STM32 Discovery, nordic dev kit,
| one of the cheap Chinese ones "pill" etc.) Design whatever
| circuits you want. Use passives, or string together ICs.
|
| 555 is obsolete tech. I see this as equivalent to suggesting
| someone buy an Apple II instead of a modern PC.
| analog31 wrote:
| >>> Why Arduinos in particular?
|
| This is a good question. I think that "Arduino" means a
| couple of different things, and it's sometimes hard to guess
| what someone means from context.
|
| There's "Arduino" the old 16-bit MCU board, and there's
| "Arduino" the development platform supporting a huge
| ecosystem of MCUs, libraries, and accessories.
|
| For instance, I use the Arduino IDE, but with a variety of
| dev boards to suit my needs. For my work, I don't need to
| cost-engineer anything, so I'm satisfied with pre-made
| modules that I plug into my own application boards.
|
| A lot of engineers dismissed Arduino long ago, and are
| utterly unaware that the broader ecosystem even exists.
|
| I don't object to a beginner choosing the original Arduino
| board, for which there's huge amounts of tutorials and
| documentation. And then, maybe graduating to a more
| performant board if they take an interest in more advanced or
| specialized projects.
| cruffle_duffle wrote:
| I always use the term "arduino" when I describe any of the
| MCU "space" to somebody not in the field. Odds are much
| better that a person heard of "those arduino thinks you can
| use to program your lights" than "esp32s3" even though the s3
| is my goto microcontroller.
|
| The second the conversation steers towards actual product
| selection... that is the time to introduce the MCU space and
| steer them to the right fit. You do always have to remember
| that most of those arduino MCU's have a 5 volt logic level
| that is more compatible with "LEGO part style electronics"
| than things like the ESP chips.
| qq66 wrote:
| The problem with starting with a 555 timer is that the things
| you can make with a 555 timer aren't impressive to kids
| anymore. Oh, you made a sound that gets higher pitched when
| there's more light on it? I thought that shit was amazing when
| I was 8. But my son wouldn't look twice at that. So we started
| with Arduino so that the first thing he created was something
| he saw as "cool."
| OJFord wrote:
| I wonder if that will come around though, where it's cool
| because it seems so simple or 'real' compared to black box
| software or AI walking talking robot or wherever we are.
|
| I grew up interested in stuff like that, taking walkie-
| talkies apart and building electromagnets with nails etc. -
| despite the availability of the world wide web & DAB radio.
| racked wrote:
| I disagree. I as an adult with zero prior experience with
| electronics have recently completed the book "Make:
| Electronics", which contains such experiments, and I got a
| sense of amazement very much resembling one that a(n)
| (intellectually curious) child would have. A 555, a couple of
| trimpots and a speaker can be loads of fun!
| tzs wrote:
| One of the circuits on the site is a 20000 V zapper [1].
| Would even that fail to interest today's kids?
|
| [1] https://www.555-timer-circuits.com/stun-gun.html
| guerrilla wrote:
| Link to your kits?
| stonethrowaway wrote:
| Seconding this.
| rigmarole wrote:
| I'm in a 3 year mechatronics program, and we covered 555,
| LM741, and similar ICs in our 2nd semester
| PLC/digital/electronics class. No microcontrollers until year
| 2. I don't feel I conceptualized it very well, but it gave me a
| good whetted appetite to dive further.
| cruffle_duffle wrote:
| > It's a shame that Arduino has effectively truncated kids
| learning with a full MCU as the "building block" of their
| learning
|
| There is a reason I didn't truly get into electronics as a kid.
| Only in adulthood with the introduction of the arduino (really
| esp8266) did any of that stuff click enough to get my interest.
|
| All that analog stuff just got in the way from what I actually
| wanted to do. Build cool stuff. But back then there was way too
| much "complexity" between me and whatever cool thing I wanted
| to build and none of it was the good kind of complexity.
|
| Starting out with modern MCU's take all that away and let me
| build at the level of the project where what I do actually
| impacts things. If I had to worry about all that analog stuff,
| I never would have bother, just like as a kid I never bothered
| --I just did all my cool shit on the computer instead!
| ChrisMarshallNY wrote:
| Holy cow. Those things are still around?
|
| I cut my teeth on them, about 40 years ago.
| pugworthy wrote:
| Clark Zapper... Hmm sure offers some interesting properties!
|
| > This device is used tocure, treat and prevent any disease. It
| will cure anything.
|
| https://www.555-timer-circuits.com/clark-zapper.html
| skinwill wrote:
| The internal diagram appears to be incorrect,
| https://www.555-timer-circuits.com/inside-the-555.html
|
| The internal resistors should be connected to the upper
| comparator. Also, that diagram just seems confusing. Something
| like this makes more sense:
| https://www.theengineeringknowledge.com/wp-content/uploads/2...
| moffkalast wrote:
| > VCC +4.5 to 15V
|
| With everything going 3.3V these days with no 5V tolerance (can't
| have nice things ofc), is there some kind of 333 timer that would
| do the same job but down to those logic levels?
| kilpikaarna wrote:
| LMC555
| wkjagt wrote:
| I recently used a 555 (and some other simple parts) to fix some
| timing issue my ham radio's internal CW keyer seemed to be
| having. Maybe I could have used an ESP32 module that I also had
| lying around, but I could run the 555 directly off of the ~12
| volt power supply, and it was also more fun to build the little
| circuit.
|
| More details if curious:
| https://www.reddit.com/r/amateurradio/comments/1eo9ki7/xiegy...
| peter_retief wrote:
| Probably the first IC I used.
| wkjagt wrote:
| The awesome Ben Eater gives the clearest explanation I've seen of
| how the 555 timer works internally:
| https://www.youtube.com/watch?v=kRlSFm519Bo
| timonoko wrote:
| Apropos. I made TV-surveillance unit when 555 was almost brand
| new. Maybe 1977. The start of a picture was long negative pulse,
| easy to recognize with 555, which triggered second 555, which
| triggered third 555 in unison with the horizontal scan pulse.
| Thus you had fairly accurate point selected in the screen,
| showing a dot, while camera info was sampled and compared to a
| preset value. Thus the watchmen could use few knobs and select a
| point in the screen, which would raise an alarm when illumination
| changed. Because it was so cheap, you could select multiple
| triggering points. No fancy microprocessors this time, which were
| too slow anyways.
| qwertygnu wrote:
| Whoa that's a really cool application! Another example of
| limitations begetting creativity.
| sitkack wrote:
| Thats awesome!
|
| You could make it so you could control it with a light pen. It
| would integrate over a window of a single scan line?
|
| A slightly more complex device could retrigger and sum into a
| bucket brigade and integrate over a region.
| 0xTJ wrote:
| I find the pin description and internal schematic a bit lacking
| on this website. Pin 5 isn't shown internally connected to the
| voltage divider, and is simply described as "affecting the
| timing".
| JuanTono wrote:
| The NE555 helped me get my first tech job in high school after I
| gave a presentation at a Nodebots community meetup. (It also, in
| some way, helped me land a job at Texas Instruments while I was
| in university during the COVID pandemic.) It was also the focus
| of the first tutorial I made for Instructables a few years ago. I
| always remember it fondly.
| relwin wrote:
| Without the 555 how can we have such fun make contests? The
| original www.555contest.com by Chris Gammell and Jeri Ellsworth
| (2011) had a tremendous response. 11 years later Hackaday held
| one with very creative entries. If you enter a contest you'll be
| forced out of your comfort zone (programming with solder) and
| will appreciate MCU's even more when you're done! If you're lucky
| you'll get a phone call from (the late) Hans Camenzind as I did
| in 2011. And maybe you'll invent something goofy, like "Le
| Dominoux": https://youtu.be/PQOjkuJtBfM?si=Np2MSKgAp4ULwzcl
| squarefoot wrote:
| I'm probably being unpopular writing this, but I never quite
| liked the 555. Not diminishing its value and the ingenuity that
| went into its design; I rather found myself much more attracted
| by CMOS gates, also in analog circuits. One day I was playing
| with PLLs and to better understand how phase detectors work, I
| built a proof of concept motion detector off a single quad xor
| chip (4030 probably), 1st gate working as ultrasound oscillator
| connected to a tx capsule, 2nd one biased as linear amplifier
| with input connected to a rx capsule, 3rd gate working as phase
| detector taking both 1 and 2 gates outputs, 4th gate driving a
| LED, which would flash every time I moved the hand in front of
| the capsules as I was delaying one of the two signals, which
| triggered the gate. Very fun and instructional. The interesting
| part is that a CMOS digital gate can become a decent linear
| amplifier if properly biased, not unlike more common opamps, so
| where high linearity or fidelity in audio signals aren't a must,
| it can be quite an interesting part.
|
| As an example, here's a equalizer built around a 4049 quad
| inverter gate chip.
|
| http://www.runoffgroove.com/mreq.html
|
| As for digital gates, I couldn't recommend more the TTL and CMOS
| cookbooks by Don Lancaster: they're a goldmine of ideas. 2nd one
| is available for free at author's site.
|
| https://www.tinaja.com/ebooks/cmoscb.pdf
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