Have you tried Arduino yet? The website has a lot of good tutorial information. https://www.arduino.cc/en/Guide/HomePage should get you started.
I agree with the Arduino approach for learning: try something that immediately gives feedback.
On a more concrete example you can start with Make: Electronics book by Charles Platt. PDF of the first edition (2009) is available from Makezine's own CDN. The book encourages learning by discovery. The leading text makes it clear:
Burn things out, mess things up—that's how you learn.
The most important thing is to tackle projects frequently and get yourself involved with other people doing the same. Learn by doing! I found books, videos, and so on of limited utility by comparison. I'll include an unreasonable quantity of my notes below.
Some useful resources:
List of initial things to learn:
How to read component datasheets (you will be doing this a lot). Actually I think a lot of my electronics knowledge was picked up from just absorbing datasheets like a weird sponge of some sort.
How to order from Mouser / Digikey / RS Components / Arrow / McMaster (these are also a great source of datasheets)
Basic laws of electricity and magnetism (any freshman university physics textbook is OK -- these pop up used all the time, and even an old one is OK). Just do all the problems in each chapter and you'll be fine. Or you can tackle "The Art of Electronics" if you like.
If you're into analog, this is a classic (and free!) text : https://web.mit.edu/6.101/www/reference/op_amps_everyone.pdf
Soldering is actually pretty easy, just buy some resistors and some prototyping board and get some practice in. You'll need to learn surface mount soldering to get access to good and cheap parts later on, but thankfully, it is way easier than it looks. Like, really a lot easier than people make it look.
How to order manufactured circuit boards from a factory using a design in KiCAD (this is actually pretty easy and cheap!)
These days, a lot of components can be purchased on pre-built 'modules' that fufill a certain objective. For example, a temperator sensing module might have a sensor and all the supporting components on a little board, so you just connect power+ground and data. These are made specifically with learning in mind and are made in Asia at a very reasonable price -- do note though that reading the actual datasheet of the parts in question will give you much deeper knowledge over time.
Tools to buy:
Platforms and Communities to Consider:
Other Stuff:
Ping me if you get stuck or have questions :)
Oh wow! this is a lot of great detail! is Rust at all useful for embedded applications, or am i essentially restricted to C/C++? Is Adafruit also a good resource or not as much as the others? Also, besides the obvious differences in form factor and ease of use, what’s the objective difference between the RP2040 chip, and, for example, Sparkfun’s “Pro Micro” or “Thing Plus”, or is the ease-of-use by itself the main selling point?
There are a lot of differences, but I'll try and go over the high level ones. The RP2040 is a chip, and the others are boards -- so I'll compare the chips on them.
The RP2040 chip is really powerful overall, and does some odd things with I/O that let you do a bunch of very fast, precise things. You also get a lot of I/O pins and they are very well-behaved. The main advantage though is that it works well in both Python and C++, and is well-supported.
The ESP32 based board (Thing Plus) has integrated WiFi. The ESP32 is a great chip, I use it a lot, but it has some unfortunate quirks. First, it has a very high clock speed and decent memory, making it quite powerful. However, if you glitch out the network stack via your code, it can have some problems with unexpected resets. This was much worse with the earlier-generation ESP8266. Secondly, the I/O work much more slowly than the system clock (if I recall correctly), and they are picky about what state they have on startup -- some go high as part of the boot process, others must be high or low on boot but can be used after. This is actually quite a pain sometimes. It's a great chip overall though and works well in C++.
The Pro Micro uses an ATMEGA32 chip. I'm a huge AVR fan so I don't have many bad things to say, I like it a lot. It is much slower than the other two chips though, and has less memory. Probably it's best to use C++, but you ought to be able to use Assembly too if you like. The I/O on AVRs are really well-behaved and usually operate at the same speed as the chip, which is nice when you need precise timing! The best thing about it though, is it can use much less power than the other two options, if you use the sleep modes right. So you can build neat battery-powered applications. Finally AVRs have excellent datasheets -- there's rarely any ambiguity on exactly how any system on the chip works.
Overall, I'd choose an RP2040 board if I wanted to use Python and do IoT/Robots/whatever (you can buy boards with or without WiFi), an ESP32 based board if I wanted to do IoT stuff in C++, and the Pro Micro if I wanted to do low-level, low power embedded stuff in C++ or assembly (and maybe branch out into other AVR chips). The C++ options mean you can use the Arduino IDE and their libraries.
Holy shit (sorry)! You really know your stuff, or at the very least, I don’t know my stuff! I’ll keep in mind the stuff you said about the ESP32 and the ATMEGA, but I was more so referring to the editions of those dev boards that use the RP2040!
https://www.sparkfun.com/products/18288 https://www.sparkfun.com/products/17745
After reading a bit more, it seems that pretty much the only difference is the IO and other supporting hardware besides just the chips. If someone (me) were working on a project where solutions like these particularly-powerful microcontrollers are required, when would it make more sense to use one of these pre-made boards for computing rather than making your own PCB designs including the chip? Is it mostly for projects where extremely compact form factors (and/or other shenanigans) aren’t necessary?
Glad to help :)
Besides the I/O and supporting hardware, the clock speed is wildly different between these 3 chips -- that's worth considering. By that metric, the ATMEGA based designs are the slowest by far -- although somewhat faster than you'd estimate since they usually operate 1 instruction per clock cycle, whereas the other chips are a few clock cycles per instruction (they are still way faster than the ATMEGA line though).
Regarding pre-made boards vs. your own? I think there are three things to consider:
Pre-made boards are awesome for prototyping. Making sure the damn thing will work (feature-complete) before designing your own board is a good idea. Then, make your first board with all features added in (this is important), but expect to iterate at least once (make revisions and order boards a second time). There's no such thing as premature optimization in hardware design -- it's not like software where you can just design the core of an application and then build features as you go. This is why always designing prototypes to be feature-complete is a good workflow, and generic development boards are a good starting point for this.
Designing your own board is really easy for AVRs. I do this all the time, lately with the Attiny10. Honestly there are a ton of AVR chips out there, and not all of them have affordable / popular development boards, so often it's worth making your own for use in item 1 above (...really you just need at minimum power and a header to break out the pins for ISP programming). Then when you want to make your final widget, you just expand your development board design, which lets you make a really miniaturized and streamlined thing! You will need an ISP programmer though, like the AVR-ICE (which has a nasty but minor bug in the design -- ping me before buying one and I'll save you 2 days of headaches setting up).
A neat trick is to design your own boards and still use a dev board (so making your own boards and buying premade dev boards are not mutually exclusive options). This is especially useful with the Pi Pico and ESP32 (where making a dev board is less beginner-friendly) -- a cheatcode is "castellated mounting holes". These let you solder (for example) a Pi Pico dev board directly to your own design as a surface-mount component. You can do this by just adding a socket and using header pins too, but SMT + castellated mounting holes lets you keep the design small and reliable.
BTW when designing your own boards, committing to SMT parts (where possible) early on is one of the things I'm really glad I did. You don't need much tooling to do it. Just a solder paste syringe, a toothpick or pin, some tweezers, and a hot air rework station (included in some soldering stations). Even 0402 parts (about the size of two grains of salt) are pretty easy to do by hand. It's amazing the level of miniaturization that you can achieve these days this way, as a private individual with a very modest budget!
Finally, the Arduino products are generally very good dev boards, whether or not you're using the Arduino IDE (you can still program them ASM or non-Arduino C++). So for any chip that an Arduino exists for, it's an excellent starting point -- although you may want to design your own board one day to remove unnecessary stuff if it comes out cheaper and you go through a lot of them, or just for the experience.
I guess my question to you would be what are your goals? Do you have a project in mind? Do you have a technology, Analog, RF, MCU, FPGA, embedded design? I tend to learn a new thing better when I have an end goal or project to work towards. Depending on where your starting from, a pi might be a good place to start too. You still have most of the I/O and busses of an Arduino, but you can program everything in python, and you have the resources of a full OS too.
Probably stuff like microcontrollers/embedded applications! (I’d like to think) I already know much of the higher-level concepts of computers and how they work, I’ve messed around with programming in Rust or C#, I’ve been daily-driving linux for a few years, I’ve wrote software to do basic tasks for me, but my end goal is to apply my experiences to the physical world. I know very little about the basics of electronics, the physics of it, why PCBs are designed the way they are, etc.
I guess I’d like resources for the lowest-of-the-low-level stuff? Like “How electricity in general works”, “Use-cases for resistors”, “Why you sometimes see capacitors in weird places”, etc.
I’m just now realizing how vague my original question was? i’m sorry about that haha.
I don’t have a particular goal in mind though, i just think this stuff is cool, and I’d like to at some point be able to sit down and make something wacky or useful with KiCad/similar.
I'll start off with your questions are a outside of what I know well. In general to do stuff with electronics, you don't need to know the physics behind it, but the equations that pop out. Mainly V=IR, Almost everything goes back to that. Behind the scenes are lots and lots and lots of differential equations. Alpha Pheonix has a few good visualizations for resistance. He has a water based demo to visualize voltage and resistance, and a maze demo showing how electricity "finds" the path of least resistance. ElectroBoom probably won't teach you too much, but can show some interesting things you can do. EEVblog has some good lectures. For specific applications Digikey and Texas Instruments have some basics, and there are many lectures online available.
I think the questions you asked are a little more on the physics side than the electrical side, and the specifics I think of as a dark art that comes with experience. In general most capacitors you see are blocking DC on an AC circuit, coupling capacitors that are smoothing the power circuit, or capacitors to control/tune something specific. Those control values would be given in a datasheet. Resistors are often going to be current limiting, voltage dividing, or "pulling" a high impedance signal. To design something you often just need the rule of thumb, and not necessarily a deep understanding of "why".
EEVblog looks great! lots of material there! glibg10b mentioned the book "The Art of Electronics", is this a good source too?
That is an excellent source.
Great Scott has a series of videos about basic electronics concepts and components. Highly recommended: Electronics basics
That's a really tough and broad question to ask. I would start with something you're interested in and dive down the rabbit hole from there.
If you narrow it down some then you'll probably get more useful tips/links for what you're looking for.
edit: formatting
Pick a project and get started, you'll find the info needed to finish it afterwards.
I just built a handwired ortho split keyboard, microcontrollers, firmware, soldering, wiring, maybe that tickles your fancy?
For questions about component-level electronic circuits, tools and equipment.
1: Be nice.
2: Be on-topic (eg: Electronic, not electrical).
3: No commercial stuff, buying, selling or valuations.
4: Be safe.