555 Timer Circuits

> 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.

> 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.

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.

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.

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.

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.

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.

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.

> 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?

> 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).

... 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.

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.

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.

I’d imagine pretty common, at least back when it was uncool to be a “nerd”. Hormones are a powerful drug, and at least until I figured out what it was all about, girls were way more fascinating than electronics.

Sex derails the potential of young humans in so many ways, yet the process of reproduction is so arduous that it makes sense that we’d end up wired to prioritise it heavily. All it would take is for young people to wise up and we’d be extinct within a century and a half lol.

We’re seeing the results of not valuing the labor that is creating a home and raising children in systematic rapid population decline. (Which might seem ok, but in most situations, it is socioeconomicly catastrophic)

We need to learn to overtly value the huge labor sink investment that motherhood , fatherhood, and family stewardship entail.

There are things more valuable to humanity than the ability to concentrate wealth and power at the expense and to the exclusion of others.

The whole drive to concentrate wealth and power is fundamentally based on sex anyway. It seems a great poverty to not acknowledge and socially celebrate the skills, labours, and sacrifices of parenthood.