It's incredible how cheap it is to get custom PCBs made at prototype scale these days, even ones with advanced features. It feels like we're living in a golden era of custom manufacturing.

OK, so people are ordering a custom PCB from China for a one-off? Whatever happened to making them at home? I remember my brothers doing this in the bathroom sink with a board coated with copper¹, some special markers to draw the circuit on the board and chemicals to wash off the extra copper. I’m guessing they might have used our dad’s electric drill to put some holes in the board as well, but looking at the article, this doesn’t seem like an order from China need.

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1. Some details may be incorrect as I was 10, this was the late 70s and I only saw the results, not the process.

JLCPCB is often the manufacturer of choice with DIY PCBs, and the reputation is well deserved. I recommend them as well, have never had an issue with what they've made. It's a bit pricier for a one-off board given the MOC, so it's preferable to do some sort of group buy if you can.

It's always cool to see people discover KiCad and the amazing world we live in now where a hobbyist can come up with something that can masquerade as a commercial offering.

The transition to SMD and having the "fab" do the assembly was another hurdle for me.

Now I tend to consult LCSC Electronics at the same time I am designing my circuit: checking availability and price of the various components I am proposing to use in my design.

Nice board, looking forward to seeing your next one. A little feedback, helpful I hope:

A "via" is basically just a wire stuck right through the whole board top-to-bottom. (Okay, it's not really a wire. They drill a hole and then chemically grow a layer of copper that fills the hole.) You can connect the copper pattern on any layer(s) to that "wire", so it's often used to route a signal from one layer to the other. But you already have a real wire going through the board: the GND header pin! So no via is necessary; just connect directly to that pin on each layer (kicad probably did this for you automatically). This trick works with all thru-hole pins.

For RF or high-current applications, sometimes you cover a board with a grid of vias, just making redundant connections between the planes all over the place, "stitching" them together. But careful, add too many vias and the PCB shop will bill you extra.

Putting a GND pour on the top layer is a good idea. It's lower-impedance than individual skinny traces, and takes less/zero effort to route. The GND trace you manually routed isn't necessary; you can see by the transparent-red shape that kicad already has copper there. However, you ended up with a little "island" of dead copper between R2 and C2, which is the real reason you needed the via.

A better approach would be to use the bottom layer for +3.3V power instead of a redundant ground pour. This gets rid of the +3.3V traces (BTW, best to use a single, thicker one instead of 2x side-by-side) and unifies the island into the ground pour. Even though this is a micro-power application, playing the traveling-salesman game with long scraggly power traces is never a good idea. You would still need vias to connect each top-layer +3.3V SMD pad to the bottom-layer power plane, but the signal-integrity benefits of a plane make this worth it. Maybe the absolute best is an uninterrupted GND plane on the bottom and a +3.3V pour on the top.

Putting SMDs on the bottom side makes the board cost more, so good call leaving them all on top, but putting traces on the bottom layer is free. So you can even move signal traces between layers to avoid cutting up your planes too much. It's "fun" with big complex boards, like untying a giant knot...

You are very miserly with your +3.3V global net symbols in the schematic! You can place as many as you want to optimize the schematic's readability. Especially near the CSB pin, the 4-way solder dot looks like some intermediate signal in a voltage divider, but it's actually just +3.3V. Same suggestion with GND -- basically, it's more informative to read "this pin is GND, and this pin is GND" than "these two pins are connected, I wonder what they're doing...oh, it's all GND".

Pull-up resistors are usually oriented vertically, too, so they graphically pull "up"!

Anyway...I hope you don't mind all my constructive criticism. It's nice to see something on HN I know about!

Wow, very very similar to my first PCB, a breakout board for the TSL4531. I ordered it from OshPark back in 2016. Used the exact same soldering iron, and a Quick hot air station, though it's the less fancy one than you have.

https://github.com/bschwind/tsl4531-module

https://imgur.com/ozk7UuS

(sorry for imgur, not sure what people use for image hosts these days)

I then went on to also make a BME280 breakout:

https://github.com/bschwind/bme280-module

From there on I've made various PCBs, and thankfully they've pretty much all worked on the first try. I do take a lot of extra time to verify the design and double check all the datasheets.

Does anyone else remember when designing and assembling your first pcb involved marker pens and ferric chloride?

This guy, with his air quality sensor, should get together with the guy yesterday that built a fan controller. Connected, fans could turn on when really needed. That's the basis of intelligent HVAC.

Are there any low cost US based PCB mfgs? Part of me thinks we should support our local supply chains, or should I not care?

I have made boards but never actually used them (the delay between need and supply is too long for me)

I wish I could 3d print a board with all its components - instant gratification (which incidentally was one of my half baked projects)

Did you find out that designing, manufacturing and testing PCBs are very interesting, but also very exhausting. You have quite a lot of repetitive jobs, especially paper work to do.

I've been trying to make a PCB but it's just so annoying having to sift through pages and pages of listings in order to find each individual tiny component without minimum order quantities of hundreds or more. The process of finding each component is so tedious that I gave up. (I was using EasyEDA hoping it would be easy to find components I could actually order -- nope)

PCBs are very neat, but that shipping time is a boomer when you are prototyping and you really don’t know what you are doing.

This feels like you asked claude how to make a PCB.

i suck at welding

In addition to what others said, home-etched PCBs are just much lower quality. We're no longer living in a world where every component has leads on a 2.54 mm grid, so tolerances matter a lot more. Also, SMD means you really need vias and a solder mask.

The problem isn't that people outsource it, it's that they need to outsource to China. That's an abject failure of domestic PCB manufacturers who simply don't want to deal with retail customers.

What happened is that you can get a set of 5 custom PCBs for about $2. The quality is much higher and you don't have to deal with nasty chemicals. I'll never manually etch a board ever again if I can help it.

> Whatever happened to making them at home?

That method works for creating single sided PCBs with through-hole components or rough SMD parts. Double sided PCBs are more effort but still possible.

But everything more complex than that - multiple layers, blind or buried vias, fine-pitch SMD, anything involving clock frequencies higher than say 50-100 MHz or depending on specific impedances or capacitances, or requiring stuff like vias to groundplanes to dissipate heat in copper? No way even for a dedicated hobbyist. And you need special equipment to make a proper stencil if you can't use a soldering iron due to feature size or because it's impossible otherwise (=BGA parts).

And where it gets really spicy is sandgrain sized SMD parts (0201 and smaller). Even for professional repair shops, that size requires experienced experts...

These days, a one-off PCB is dirt cheap. They’ll provide and solder the components for you, for less money than you could buy them to do it yourself.

I have a small CNC mill and can carve out a board if I don't have time to wait for ordered boards. It's a pain to set up to get it to cut properly, the boards are either one sided or with no vias, and the lack of solder mask makes it harder to solder, especially for SMD components that rely on the solder blob being a certain shape. Additionally, I find that the traces tend to peel off a little too easily, though that may be down to the Ea-Nasir quality copper clad boards I'm using.

It is pretty fast though, and worth learning if you need to do prototyping quickly. You can have a finished board in just hours instead of a week.

I still do mine at home, though I mostly only build one-offs with older style thru-hole components where tolerances are not as sensitive.

Usually I can get away with using a simple Sharpie marker mask, though I've also had good luck in the past with the toner transfer method for more intricate designs:

https://www.thompdale.com/pcb_etch/gotee_board_production/Ea...

I knew someone who destroyed three surface pro keyboards with chemical etcher.

I've got a cat and live in a carpeted apartment. I prefer to keep most projects "dry" for that reason.

Buying custom PCBs from China makes sense if you're interested in making electronics. It was more than a decade ago that the equation shifted to the point that making them at home has only made sense if you're interested in the process of making PCBs themselves.

Things like soldermask, multiple layer stackups and plated holes and vias are standard on dirt-cheap Chinese boards but are challenging and time-consuming to do at home.

I used to do this at home. Either thermal transfer or also used a flat bed plotter with an adapter for a Staedler permanent market to draw directly on the PCB. Fun times. Ferric Choride IIRC for etching or you could also use hydrogen peroxide which was much slower...

And yes drill through holes.

Ofcourse only good for two sided (layers) boards at the most.

> So no via is necessary; just connect directly to that pin on each layer (kicad probably did this for you automatically). This trick works with all thru-hole pins.

Note that without a plated through hole (vias are small plated through holes, those designed for component legs are bigger) the solder will only adhere to one side. For mounting large components where vibration may be a problem this will make the pad weaker & more likely to lift off. A plated through hole lets the solder flow through & bond to pads on both sides. So you sometimes do need plated through holes.

Otherwise I agree. These days 4-layer boards are so cheap it's often worth just dedicating an entire layer to ground, and one to power. E.g. Signal, ground, power, signal. All your ground connections become vias. Most of your power connections are vias to a lower inside plane. Your signal traces are available to probe & rework easily. You get a bit of distributed capacitance from the power & ground planes.

For a simple-enough design, I'd just route the signals as on a 2-layer board. Play around with placement & orientation of parts to minimize overall trace length. If you have some A-B duo with many connections between them: place those first & then put the other parts.

Then fill the remaining space with power planes. GND on one side, most-used supply voltage on the other side.

That way you reduce/avoid the need for blind (or worse: buried) vias.

Another trick: route signals roughly east-west on one side, roughly north-south on the other side, and use a via where you change direction. Many early (complex!) computer mainboards were done that way on 2-layer boards (often using through-hole IC pins or passives as via).

You shouldn't really need 3+ layers unless you get into high density stuff like many-ball BGA parts & the like.

This is great! Thanks for the detailed write up and suggestions to improve. Like I said, this is my first time doing it and I have no background in EE or PCB design. If I make something else I'll give your suggestions a try.

Part selection is often the bulk of the work in a PCB design, yeah. What tools were you using, though? In general the parametric searches on digikey, mouser, etc are pretty good for the standard components. For stuff like resistors it's generally easiest to find a particular range and pick from those. You might find most of those have a MOQ but they're cheap enough it's usually not a major issue.

What kind of part? I use Octopart for a lot of things, like ICs (sometimes some variants are available in low quantities but others aren't and only in thousands).

For stuff like passives it's usually easier to use Digi-Key or Mouser and you can filter by MOQ so you only see things that are available individually.

DigiKey used to be a good place to get. Also design for parts you can get... In the old days you could also get samples from chip companies if you asked nicely. No idea if anyone still does that.

So a lot of this goes away if you try to stick to jlcpcb basic parts from lcsc, and you sort of develop preferred components for things. Another trick is when in a category, for example angular hall sensors, once you have the key attributes like vin, smt, etc, sort by quantity desc to see what parts get heavily stocked, that tends to indicate what is popular in industry and likely to be a good generic fit. Out of the top 10-20 pick according to stock level against price. If youre ordering from jlc, look through lcsc and you can do pcba with them, or get the parts shipped with the pcbs. Otherwise digikey, mouser (good for connectors), farnell, rs etc, roughly in that order. You will quickly learn for a lot of components there are very standard parts everyone uses. Diodes, inductors for example. To some extent if your footprint is already in the jlcpcb library, its popular and use that. Ie theres 1 smd push button that is basic on jlc and has a footprint in kicad default library. Youd be a little crazy to use anything else. Make all your resistors and caps 0603 or 0402, jlc stocks those the most, vs spotty coverage in 0805 or 1206.

But you find each time you find something in a category, a hall sensors, an encoder, a capacitance sensor, gpio expander, adc, you just file that away as kind of solved and next time you hit that part first before finding alts. Over time you have to dig about less and less. But dont bother with things like resistors, caps, etc that are basic. Even mosfets, unless you have special needs the 3 main types jlc has as basic are fine. Dont get some odd package thats technically two mosfets in one, just put down two basic mosfets. And if you do need a more 'advanced' part, look what is on jlc's promo list atm. Theres very popular stm's for example that are prettymuch constantly on promo (promo is they have the part loaded in mid term for some big customer so you might as well piggyback. Means no loading fee. Adds up)

Llm's can be useful for sifting the sand. Narrowed it to like 30 options and still dont know whats the best pick? Export search as csv and ask your favourite stochastic parrot which part would work best for your application and why. Dont ask them for part numbers though, completely pointless.