I enjoyed your post - PCB routing is often an act of 'zen and the art of..' for me and I recently did a similar exercise for an esp32.

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for an introduction to the CAD software, Kicad, which this project uses, I really liked "Shine on you crazy Kicad": https://www.youtube.com/watch?v=eMW9ohCbcik&t=27s It takes you from basics to buying a PCB from the manufacturer.

Breadboards[1] with breakout boards[2] (the Pi Pico in particular is incredible, having an unusually detailed and correct datasheet). MicroPython is probably a great way for gets to get started on the compute side of things. Once you have something working on a breadboard then you can "graduate" to PCB design (and there's nothing wrong with designing the PCB to take a breakout daughterboard) - possibly perfboard as an intermediate step. A high quality breadboard and wires are very important - I guess diagnosing a loose connection is a learning experience, but it would be an overall hindrance to learning if encountered frequently.

Have many spares of all components (including breakout boards) handy - they will probably summon the magic smoke a few times.

They will likely quickly need to learn how to read data sheets. You can often get away with copying the "typical application" and avoiding the real technical stuff.

Friendly reminder: those brains are still developing. Adequate exhaust is extremely important (even if you are using solder-free, flux fumes are varying levels of toxic). You want those fumes going out of the window, not via a filter into the same room. Any complaints about headaches are serious: you aren't extracting the fumes correctly. There are a few important things to know about soldering: "there is no such thing as too much flux," "solder likes to flow towards heat," and "heat the thing and apply the solder to the thing (not to the iron)" (to keep the technique at its most basic).

The often recommended Hakko FX-888D is just plain awful. The Pinecil is way better (yes, even though its a fraction of the price) or the TS100/TS101.

[1]: https://en.wikipedia.org/wiki/Breadboard [2]: https://www.raspberrypi.com/products/raspberry-pi-pico/

I personally love this macropad tutorial and it's how I got into doing circuit board design in highschool: https://hackpad.hackclub.com/. Before doing this, it's really helpful if they have experience messing around with breadboards, so getting them a kit can help them into a soft transition too!

I like to suggest making a macropad, then a keyboard, then going into a devboard, and then starting to make your own projects. But for kids that aren't quite in highschool yet, it can feel quite intimidating and the learning curve is moderately high, so getting them playing with breadboards first might be the best option ;)

Hack Club will also give you a grant to cover the entire cost if your kids are over 13 through their programs like stasis, fallout, or forge (you can check their site for more info)

Strongly feel the logical progression is: (1) Wiring third party devices and modules to an existing MCU board and programming it (2) Making a PCB to plug modules and the MCU board in to (3) Making a PCB with integrated peripherals and only plugging the MCU board (4) Making making a whole board with everything.

The MCU is typically far more fiddly than the devices (eg. crystals, storage, buses with conditioning, power stages, etc.), so continuing to plug the MCU in to a PCB while integrating peripherals is a good. You really need to be able to read a datasheet to do a nontrivial board and that brings in quite a few elements of electronics which are nontrivial for kids to grok without hand-holding and a lot of explanation.

Pick an MCU with easy USB-C programming. RP2040 is a good modern option.

Does this help you build a custom PCB that you would send to a factory or like just design and simulate something you could build on your own? Or both / neither? I'm not fully understanding what this project does, could you offer insight?

Worst is when I have a full board and schematic, but its for some other EDA program. Importing EagleCAD shit into KiCAD is agonizing, endless tedium. It's not like I'm not grateful to have free and open-source designs (specifically I'm talking about Adafruit, I like them, but all they use is EagleCAD), but goddamnit why can't it just be easy for once :(

Most electrical engineers use “reference designs” published by the IC manufacturers to design their PCBs, although any open source commercially available design can act as a reference. They essentially copy the schematics from the PDF (or import if file formats/converters allow), ripping out whatever they don’t need, then reroute the PCB using their layers.

In some cases, when their PCB fab layer stack up is similar enough to the original board, they can go a step further and copy paste most of the PCB into their design so that any signal integrity work carries over. Realistically this is only really practical for low speed designs but still useful for a whole class of electronics.

I don’t use KiCad but software like Altium support modular schematic sheets and PCB rooms so theoretically it can imported into that (since KiCad’s format is open source S-expr)

I could imagine small companies that rely on these boards and that also have their fab and sourcing pipelines set up would be able to easier source these themselves. Just have to generate the Gerbers (fabrication output format most manus need) and then send it off as part of a larger order, etc.

Especially if you're able to replace certain small/passive components with those you already have in bulk, it could be a potential cost cutting measure.

Just a guess though.

For my case, they'd be useful if I wanted to know how certain subcircuits are designed or laid out.

Even for beginners, taking it into kicad, enabling the selection of only tracks and vias and deleting them all, then doing a full re-layout of the board as practice would be a cool project if you're wanting to learn.

I've got some projects that use ADCs on Pi "Hats" that connect to controls, I could see a future version which integrates that ADCs and pots directly onto the board to get a slimmer profile. It's quite handy, I wonder what the unit cost is with assembly at JLCPCB.

Yes to the first half, for the most part.