Teach Me PCB

by zdw • 5 years ago

193 86 5 years ago

baybal22• 5 years ago

Doing PCBs for 12th year now without a complete engineering education.

Just as the lack of formal CS background imprints on your lifelong experience with computer languages, the same way is the lack of EE background.

From time to time, a recent grad hire comes by, and fixes my work, and shows me where I screwed up with a few calculations on a pocket calculator.

cinntaile2• 5 years ago

It's likely that it's very specific knowledge that you lack no? If you wantee to address that it should be possible with self-study?

crispyambulance2• 5 years ago

It is theoretically possible with self-study, but the problem is it's still very easy to make practical mistakes even if you "understand" all the theory.

Eventually you run into a problem and have to re-spin the board with no margin of extra time (assuming this is for work). In that scenario, having access to an experienced expert is immensely helpful.

baybal22• 5 years ago

I pretty much continue self-study every time I stand corrected.

Things learned from junior hires: a lot in RF domain, opamps, 74XXX trickery, signal integrity measurements, fiddling with high freq PCIE, DDR, PAM4 lanes in the sciency way, and whole new world of advanced power electronics, and designing it according to standards, and codes...

NikolaeVarius• 5 years ago

Its very hard to replicate 4+ years of "required" study because you don't know what you don't know

fxtentacle4• 5 years ago

Same here. I have no formal education but I recently finished my first 12 layer USB3.1 SuperSpeed + FPGA board. Every once in a while, I have to book a freelancer to explain niche knowledge to me - for example how to calculate the impedance for the USB3 specs - but thanks to good software, it was a lot easier to learn than I thought.

By now, I have my own tiny KiCad fork to make things easier to read and look like I expect it to.

https://gitlab.com/fxtentacle/kicad/-/commits/vector_font

gmurphy2• 5 years ago

Any tips on how to find/book those freelancers? I've been looking for similar help

le-mark• 5 years ago

This sounds exactly like a pcb project I have in mind, plus a bunch of ddr3. How hard is it starting from almost zero? I imagine diy isn’t realistic, how much does design of such a board cost?

tremon• 5 years ago

We didn't even cover PCB design in my EE years, the course load was pretty much evenly split between circuit theory, VLSI (processor) design, power distribution systems, and embedded systems programming. Plus the necessary theoretical background in physics, mathematics, control theory, and management.

ducktective2• 5 years ago

How to preview? Is it free? What EDA software is used?

espadrine• 5 years ago

Last year’s course indicates this:

You will need to choose a software tool to complete the activities in this course. Altium Designer, Circuitmaker, Autodesk Eagle, KiCad, and Diptrace will be shown as examples in this course.

ducktective2• 5 years ago

Thanks. I couldn't find any info about last year's course. Is it open to preview?

fxtentacle4• 5 years ago

KiCad is good and free. The only thing it lacks in comparison with $10k+ offerings is a convenient autorouter. But then again, I couldn't get automated routing to work in Altium either O_O'

ravenstine• 5 years ago

Autorouting works in EasyEDA but it still requires supervision. Settings you think would make things better like decreasing the track width can end up creating more vias rather than the other way around.

borjah4• 5 years ago

Well, I worked with altium and kicad for almost 8 years. There are more subtle differences than the autorouter, and this is basically a trivial thing because I rarely use it. For example, kicad does not have some advanced features like via fencing, via picking, lenght matching, and some more. Is true that you could download a third party plugin, but is not the same.

Variants are the same, you cannot do it in kicad and altium is a breeze. It give you the flexibility to build different versión of the board in seconds.

Also, the library management is, in my opinion, very error prone. I get the flexibility and I find it useful in some cases but...

And the last is the design rules UI/UX is very simplistic, and you need to know what you are doing. Which is not bad per se, but for a software oriented to mainly begginers, I think is a bad idea. Besides you cannot import/export rules from one project to another and this is a killer for me.

I hope some day kicad will be a solid competitor to altium but right now I cannot fully do all my work in kicad as a electronics engineer, so even Altium is expensive, is a much needed tool.

Edit: I stand corrected, kicad indeed has lenght matching.

mjhughes7• 5 years ago

I just opened guest access to the course overview. 100% free -- and we'll give parts and boards away to at least 25 people.

We are software agnostic -- you'll be grouped with other users using the same software (group for KiCad, group for Eagle, etc...)

xor992• 5 years ago

Looks good, I'm looking to brush up on Kicad or learn Altium to compare. Phil's Lab on youtube is a great resource for learning pcb design.

donquichotte• 5 years ago

Phil's lab is the first thing that came to my mind when seeing this. Phil is an excellent teacher and has great content on PCB design, digital filtering, signal processing, C programming, FreeRTOS etc. Certainly an engineer that I would LOVE to have on the team.

ChrisMarshallNY• 5 years ago

I was doing this in the 1980s (started as an EE), but those boards were crazy simple, compared to what we have, these days.

joshvm2• 5 years ago

For advanced topics, I've heard good stuff about these: https://academy.fedevel.com/courses/online-advanced-pcb-layo...

(high speed layout, BGAs, etc)

Not free, but not super expensive and they also have introductory courses ($50).

https://academy.fedevel.com/courses/online-want-to-design-yo...

fxtentacle4• 5 years ago

My recommendation would be to search YouTube for "Rick Hartley". The guy is extremely knowledgeable, yet humble, and presents things like grandpa reciting a war story. It's easy to listen to, and I'd take him being on any kind of program as an endorsement that it'll be high quality content.

The most important talk for beginners getting into high-speed is probably this one: https://www.youtube.com/watch?v=ySuUZEjARPY because without proper grounding, interference and EMI is going to destroy your HF signals (for example CPU to RAM bus).

tylermenezes• 5 years ago

He's actually done some great videos in collaboration with the parent comment's recommendation, which you can find for free on their YouTube channel.

crispyambulance2• 5 years ago

That guy is really good. He reminds of the Andy Kaufmann character, Latka, from "Taxi". He has great interviews on Youtube as well.

oytis• 5 years ago

Altium is extremely expensive though. I wonder what it would take to do the same in KiCAD.

dogma11382• 5 years ago

Altium offers their hacker/hobbyist circuit maker for free, it uses the same engine as Altium just lacks some of its advanced features and parts library. https://www.altium.com/circuitmaker

bberenberg• 5 years ago

My friends are making Flux[1] which is aimed at hobbyists and smaller teams.

1. https://www.flux.ai/

xondono3• 5 years ago

Can vouch for fedevel. It’s my goto recommendation when someone wants to “graduate” from microcontrollers into more complex designs (DDRX memory, PCIe,…)

gmurphy2• 5 years ago

I held off doing PCB stuff for a long time because the tools seemed incredibly complex and intimidating, and now I wonder how I ever did anything without it. The things I wish someone had told me:

- all a PCB is, is a flat version of your hand-wired prototype - all those crazy lines are just the wires - there's no special hidden EE magic until later

- the schematic editor shows your intent

- the pcb layout editor shows where things go

- the hard part is actually just finding schematic and layout editor files for the components you're using - github search is great for this

- you will make lots of mistakes and need a few goes - everyone does, debugging is half the fun, don't be afraid

- online PCB houses make those mistakes cheap

Things I have made with little more than introductory-Arduino knowledge:

- A wearable bluetooth ring: https://twitter.com/gmurphy/status/1372368637332389888

- A hall-effect volume control knob for my PC: https://twitter.com/gmurphy/status/1179831446204121088

- A long range garage door opener: https://www.instagram.com/p/B11m1y5J3qc/

- And currently working on a keyboard: https://twitter.com/gmurphy/status/1443048243101777921

Also, the debugging step for me got orders of magnitude easier when I got a set of PCBite probes - just drop them on and they mostly stay in place. e.g: https://mobile.twitter.com/gmurphy/status/136575328654495744...

znpy• 5 years ago

Thank you for sharing tour experience with the topic, i was wondering: where whould somebody start if all they know is basic circuit theory?

dbrgn• 5 years ago

Just start a small project and figure out how things work on-the-go :) My first one was a small PCB to control a RGB LED strip using three potentiometers.

dogma11382• 5 years ago

Unless you dealing with things where signal integrity matters any drawing program with fixed dimensions that you can reliably print from whilst maintaining dimensional accuracy if you are using the print and transfer method works well.

CAD software for PCBs becomes a must when you need to deal with a lot of components in odd sizes/package formats, you need auto routing, being able to simulate resistance, impedance or clearance for high voltage sections of your PCB or when you actually need to get your PCB manufactured by a 3rd party that has specific requirements for file formats etc.

And even then some of these 3rd parties allow upload of graphical formats for the trace and solder mask layers.

teleforce• 5 years ago

Good news, signal integrity guru Eric Bogatin has just released a guide book on circuit prototyping and PCB design fundamentals that can become an instant classic in the field:

https://us.artechhouse.com/Bogatins-Practical-Guide-to-Proto...

dognotdog• 5 years ago

That PCBite probe setup look nifty indeed, thanks for the tip (pun intended)!

PragmaticPulp• 5 years ago

- the hard part is actually just finding schematic and layout editor files for the components you're using - github search is great for this

I recommend learning the symbol and footprint editors as early as possible. Creating your own footprints is a good way to force yourself to go through the data sheet and understand what each pin does, too.

_moof• 5 years ago

I second this. It can be tedious but for some parts you won't have a choice.

jareklupinski2• 5 years ago

yup, once you "get your hand in" and only focus on the correct footprint/pad layout and a little silk, it becomes faster to just sketch out parts with fewer than 32 pins than finding (and validating!) random libs

hellohntoday2• 5 years ago

As other here have said, this is very good advice.

Early on I tried to only use components in available libraries. That was a mistake. Start doing your own footprints and symbols from the start

fho6• 5 years ago

Also: the Autorouter in Kicad is actually pretty useful ... if you use it as a tool, not as a magic problem solving machine.

I normally place components somewhat randomly, big chip in the middle, connectors at the side, small stuff close to where it belongs ... then hit the autorouter, look at the result and move around some components, hit the autorouter again, rinse repeat ...

In the end I'll end up with fairly good looking PCBs (e.g. https://imgur.com/a/rUGtBNa) without having placed a single line myself.

xondono3• 5 years ago

the Autorouter in Kicad is actually pretty useful...

For most toy projects it’s perfectly sufficient, but once you get into complicated stuff it will bite you back.

Using an auto router is like building your software by copy pasting from stack overflow indiscriminately.

cdcarter• 5 years ago

Yep, autorouter makes easy work out of hard stuff. Folks who tell you not to use it haven't spent much time using one or are working at a very different level of polish. It's super convenient to draw some important power traces and let the router do its best with signals. If it's taking too long, you start rearranging.

jareklupinski2• 5 years ago

i use the Eagle one at the end of my routing flow:

first drop VCC and GND vias if you're using power planes, then route chunky power traces, route high-speed / differential pairs, finally autoroute everything else

on some boards, only 3-4 signals aren't power or something tight, but for LED Matrix boards with thousands of criss-crossing low-speed signals and other 'fun' projects with hundred of components (keyboards!), the autorouter is really the only way to go if you want to be done in a night or two

DowsingSpoon• 5 years ago

Kicad has an autorouter? Are you talking about FreeRouting?

kop316• 5 years ago

Digikey actually makes really nice YouTube tutorials on how to use KiCAD:

https://m.youtube.com/watch?v=vaCVh2SAZY4

When I had to design a board I used that.

eljimmy• 5 years ago

Has anyone taken this course (or a similar one provided by Mark and Jess) before? I'm interested to hear your thoughts on it.

mjhughes7• 5 years ago

This is Jesse's first year teaching. He was the stand-out star of the last round -- so much so that I promoted him to instructor mid-course.

WaitWaitWha2• 5 years ago

Is there a public syllabus for this course, prior to creating an account?

mjhughes7• 5 years ago

I just opened guest access to it.

WaitWaitWha2• 5 years ago

thanks!

mjhughes7• 5 years ago

I opened guest access to the syllabus / course overview.

mjhughes7• 5 years ago

I opened up guest access to the syllabus & overview so you can see what's there. -- Mark

hyperman1• 5 years ago

Thanks

auxym• 5 years ago

Hi, looks super interesting, I'm signing up!

Is there any chance you would consider offering some sort of "course completion certificate" with number of hours? I'd be interested in getting these hours credited as Continuing Professional Development for my P.Eng. board. I'd of course be willing to pay a fee for this (which I could get reimbursed by my employer).

mjhughes7• 5 years ago

Sorry -- in the air most of yesterday. Sure -- I can offer a certificate. Do you need a hard copy? Digital? We can figure it out.

nimos2• 5 years ago

If someone wanted to do this but didn't know how to make schematics is there any recommended intro material?

malwrar• 5 years ago

I've been getting into this over most of quarantine and have successfully imitated this guy's tutorials (just had to swap out the microcontroller): https://www.youtube.com/watch?v=C7-8nUU6e3E

If you don't know EE basics you'll probably want to grok those first, there's plenty of youtube channels covering it. Good starter: https://www.youtube.com/watch?v=mc979OhitAg&list=PLWv9VM947M...

nimos2• 5 years ago

Thanks!

lbayes• 5 years ago

I've been really surprised at how simple it can be to configure complex ICs with basic pull up / pull down resistors and voltage dividers.

The (older) books I was reading got me really nervous about needing to design all kinds of complicated circuits, but most things these days are just finding an available IC and configuring it.

Well... It's not so trivial to find an "available" IC this year, but hopefully this too shall pass.

Teach Me PCB

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