N00bing My Way Through Circuit Board Design

Um, I'd like to introduce Edward Frell who is going to take us through noobing my way through circuit board design. So, thank you everybody. Thank you, Edward. >> Uh, good morning and uh, welcome to Bsides uh, and thank you for coming to the second talk here in the uh, the off main track. Um so my talk today moving my way through circuit board design it was something I started jumping into at the start of the year I'll go through a bit of the journey of uh of that just as I was writing this story it it really turned into something a little bit different just show hands for who here who is this your who has this as their

first bides yeah awesome look I I guess probably the the big takeaway I have this sizable regime my cabinets might smell of rich mahogany I have no idea what I'm doing. So I think for me the this talk started turning into a piece on here's a little journey I've gone through uh as much is of hey here's some cool techy stuff but I think for me having had my first conference like this some 20 years ago uh it's important just to to have in the back of your head you're not going to know everything. you're going to go through this journey of making mistakes. If you're going into the CTF uh at sometime over the next three days, um

you know, you're going to stuff up. You're going to make mistakes. There's nothing wrong with that. I think one of the worst things our education system has done is gone through, hey, you need to adhere to a standardized test, and if you don't meet this numerical measurement, you're an idiot. Uh quite frankly, park all of that aside, uh because I I'd say, you know, learning is more about, hey, how do we break through things? So, with no experience, uh, and with me kind of sometimes being a little bit like a six-year-old on red cordial, um, I bounced around things in a domain where I I'd say there's probably a bit of a need for focus and for

studiousness. So, why did I start doing this? Um, well, I'll go through the path a little bit later, but as I got to the end, I I started to ask my question, why did I waste so much time? Um, and I think some of that answer started to become quite sort of evident. Um I think one of the biggest issues we have in Australia is that we don't have enough people building things and doing cool stuff. Uh whether that's in trades or whether that's in technology. I think a lot of who here works in industry more broadly just a few of you who would agree with the analogy that instead of eight rowers so if you know rowing eight

rowers one coxin we've actually probably got about eight coxins and one rowers in a lot of companies uh where there's not enough people doing things and I think just doing stuff is is important not only for actually achieving an outcome but also for us as human beings building you know we build things um it's also a new school skill to learn you'll see some of the cool stuff that's uh out there. Uh also something I would encourage many of you to have uh on your journey uh as you start going through your careers for those of you who hey I'm just getting into it. Have something on the side that is kind of like work

that isn't work that is is just something that you do yourself and this being so separate to what I would do uh was just one of those things. Um and I've got a few things I'm looking to build. I also went through some really weird and wonderful discoveries that also educate [snorts] and inform me on things. Just I guess something as well to be mindful of and having talked through some of the cool stuff I've been doing here. Um just be mindful you're not going to you're not going to sell a company for $100 million because you've built something. Um and if you go into it with that mindset um you're going to set yourself up for failure. And and the

same with trying to build things for the sake of building them or hey this is going to be commercially awesome and you know I'm going to be a crypto millionaire. I think there's a lot of attitude and ethos in this world where people are going down that path and it's just creating disasters. So where did a lot of this start or where do I get the the motive? I I guess I've probably got some of my slides uh you know in and out of order a little bit. Uh if you've ever done a a team's call with me, uh you'll see this wall of badges like this that I just apply a bit of velcro on, stick them to the wall,

and you know, it's it's just a cool little background to remind you of the cool times that you actually have at events like this. But also I came across this uh device which uh was a an implant for um a USB implant which you'd put in line with a keyboard that would allow you to either uh inject sniff or Xfill data over a keyboard. I'm like this is actually kind of cool. So I started playing with this project got a couple of these printed. I'm like hey I could probably do some of this myself. But I guess probably even before that um there's been a whole heap of things that I've been playing with. Uh if you've

studied in my postgrad lab at ADF, I've built a USB micro I built a uh a bunch of control features uh using ESP32s. Unfortunately, that lab's been decommissioned. But the idea was I needed something to simulate behavior in an IoT environment. and to generate that control. Um, I just had a bunch of Arduinos that would would facilitate it. But even before that, I was building Raspberry Pies and other tools to facilitate a lot of our pen tests. Uh, you'll also see up top there a a USB Arduino Leonardo, also a bad USB. You can pick these up for about $595 out of um out of a couple of sites uh in China. Picked up a hundred of them. put them I

decided to throw this was an an experiment we did in 2017. Put about a hundred of them between Sydney and CRA. Uh getting a phone call from a certain agency in CRA after your six martini in uh Defcon uh is an interesting experience especially when someone's advisor is next to you. That's another funny story. But then this also eventually went into uh the ADF cyber skills challenge which was running off uh these ESP32s that was creating a bunch of Bluetooth wireless uh challenges. I also um got one of the GPIO pins modulating AM radio. So you'd actually have an AM radio station coming off this which was was kind of cool. [snorts] So I kind of parked things off to the

side there. Co also hit so I had other focuses. was also finding myself doing a little bit more in the wireless space and also I ended up building a bside 2023 wireless CTF as well. So, um these are just all little things that built into this bigger thing. I'm like, there's got to be more to do. So, the start of this year, I said, "Okay, look, I had fun with that, uh USB tool, but something wasn't right. I couldn't quite get it working. There's going to be other cool things there." I also started doing lowend 2021. I'm like, "Okay, can I build some really cool boards off the back of that?" and what are some cool

fun control things I can do. So, uh, look, if you're looking to get started, these sort of Dick Smith style kits that you can now get at JAR are actually a really good place, uh, to to start playing with. Um, and there's also plenty of tutorials on on YouTube, but I I think some of the structured stuff that you get out of Jar is actually a really good start. Um, I would say I probably didn't spend enough time with these and going into a little bit more of the the theory. I think I probably jumped a little bit too far ahead. Um, and for a lot of projects, so the projects I was talking about 2017 to

2020, some of this kit was really all I needed. Um, but this did start to evolve over time. And then there's also a really strong uh community in the the US, uh, the the badge creators for for Defcon. They've also got some really cool write-ups to some of the hardware they've built, uh, as well. getting familiar with the Arduino environment and building uh building pieces as well is is also important. So uh the ADF sub skills challenge, the B sides wireless challenge from 2023 uh the USBs I was talking about all had some element of um uh all were using um uh Arduinos which uh if you look at the code behind them, it's a little bit more

routine than what you'd have with say a little bit more smarts and and processing. Um, so doing that read up and getting that inspiration is actually kind of your first point to to start building things. So after you start playing with a few bits and pieces, um, you can start doing a a couple of bits of design. And look, my first point here with designing is is actually start off with pen and paper. Um, actually what is it that you want to achieve and what's the outcome you want to get to? Um, in terms of your actual design tools, uh, I've been using Easy EDA, which has been pretty pretty straightforward. You've also got got the

backend component library, uh, which, uh, has, uh, a whole heap of bits and pieces, and then a, uh, a really easy sort of to use, uh, interface. And I'll I'll, if I get a bit of time, I should be able to show you some of that um, shortly. [snorts] So, you know, after you start going through this, ideally you you work out what you want to do. You'll have your components and then you'll want to actually have your schematic lined up. Um, so you'll see here, this is a very basic schematic for um a a effectively a light uh uh for a a light on a a PCB. It's actually kind of the hello world of

like for me this was my hello world um experiment um which allowed me to just build a really cool little PCB uh we could hand out uh for for conferences. Uh so after you you build out your schematic and it all makes sense and it all all ties in uh you you'd lay it out onto your board, you'd send it to your manufacturer something profit. Um, so what are some of the the cool things that I've been working on? Um, as I said, I've just been doing just some really basic stuff with uh with simple light circuits uh to sort of build myself into things. Um, and that's slowly starting to build into even bigger boards. So, this is a personal

project I've been working on for the last few weeks uh for the Army Cor signals. Uh the the board on the center here is just a simple uh light show. Uh but as you move uh further to the left, um I've actually got a uh an ESP32 with an SD card uh a lower interface. Um the power side of this thing has actually been bugging me. And this was off my first board. Unfortunately, it hasn't powered on. Well, not that it hasn't powered on, but the power feels is really unstable where it just it glitches and it just messes around. So, it looks like I've kind of stuffed up um with uh the battery and USB interface.

I've also had another issue with uh some of my other boards on on that as well, which I'll I'll go through in a sec. But, you know, very simple ones such as uh the the two up the the front here with the the blinding lights. um um fairly straightforward and fairly easy. Um I'll go through some of my my mistakes with those boards shortly. So, one of the other pitfalls I actually had in my early stage was um seeing how I would and this was a massive learning lesson for me because I went down this AI slop black hole for about 6 weeks. Uh this is the board that uh that I built with AI and the entire power function on

it is completely screwed. Uh and it was fascinating cuz I was trying to go, hey, have I done this right? I don't know what I'm doing here. Um and it's like, well, have you tried adding this component? Have you tried adding this component? And so what ended up happening was, you know, AI is like Mr. Mey's. It's trying to be helpful and it just keeps adding out. And so it just it it went full Mr. mees and just went completely crazy and just kind of overloaded this board. And so this board I keep there as a bit of a mistake. Um, and I think this was one of my big learning lessons around artificial intelligence. What was really good and

how I really made use of it was actually identifying components to achieve an effect. Um, I could also use it just to bounce ideas within reason. I think the thing to remember whenever you're using artificial intelligence on any project is you're in control. Uh, and I think this is one of the problems that we often see. Uh, whether if it's using AI to train you for getting off meth and then saying yes, you should reward yourself with some meth. Um, true story, but it's it's I think this is just one of these fascinating journeys, especially going through new discovery of, hey, how can I use AI? And and for me, this was one of my learning

lessons and a massive uh Eureka moment of actually AI is good when you have some backend data like, hey, here are the parameters I need for my components. look at all these PDFs with the specifications for these components, what's the most appropriate and that can help you with your research and save you tons of hours. But expecting it to do things like uh business logic uh is a little bit harder. Um I think I've probably relied on it too much for battery and power management. For me, this was one of my big okay, I've stuffed up here. Um I need to go away and learn. Uh and so, you know, if anyone's worried AI is

going to take your job, it's not. I I think for me this was this is going to turn into a wider didactic of hey AI is not going to steal our job but we can certainly use it uh within reason. [snorts] So um what are some of my stuffups? Uh power planning was a big one. Um so you saw on probably two of the boards before where it looks like power management is just something that hey I screwed this up and I've got to sort of have that sort of self-realization of okay here's something that I could do better. Um, and I can go through that reflection. Uh, component selection is also another one and making sure it lines up

properly. Um, getting layouts wrong in terms of just putting everything everywhere and in the right spot. Um, I'm still trying to uh troubleshoot this one. So, the these are a set of ESP32 boards that I'm building out and doing weird and wonderful connections with other components. So, this is actually I think probably the big thing that I should have done early on, which is okay, let's build the basis of my uh wider circuit boards uh for okay, I'm using USBC to control an ESP32 and then there's going to be a bunch of points uh that I'm actually going to connect to. Um so, I was able to just build a a very basic uh board

for prototyping uh for that. Um, and so in doing so, this just created a smaller surface for me to manage and I could actually start working through things. Um, so just doing a basic build like this, if if you are going to go from your hello world with your uh with your light up to this uh or even an intermediary uh case with um uh with something such as the uh the Bides badge, starting small and keeping it easy is a good idea. Now, there's a piece I'm still trying to troubleshoot with this one. So, if you look at USB, if you look at USB, you've got 5 volt. You need to drop this down to 3.3 volt.

Um, I've been using the breadboard to achieve that. So, there's a point from USBC uh down to where I'm dropping the power where something's going wrong and I don't quite know. I'm pretty sure it's the component I've selected, but I've actually got to go through a process of troubleshooting that. And so, revisiting and relearning how to do troubleshooting has been a really big one. colors and lights. So, if you have a look at the board over here, I've actually got two different light patterns that I'm still working through. Uh, and I'm the guy that has 89 black t-shirts and now three Hawaiian shirts because of new corporate attire we just purchased. Uh, I have no style and no

concept of uh light and design. So, I'm still trying to work through that and I've realized that's probably a bit of a weakness. I'm I'm going to probably ask for a bit of help on on that. that I've got lights that are actually pointing in in to uh a part of the board which will actually shine through and create a really cool light effect. But uh as I said my first slide, I don't know what I'm doing. Uh so I'm going to get a little bit more advice on that um and think through it. Also attention to detail. So this board over here was completely uh the one in the center was completely functional. The problem is

though, the components got um got printed onto the board facing the wrong direction. So, um that was a big attention to detail thing for me. And as I said, this is about your own self-discovery, your own learning. Um the the fact that I didn't point them in the right direction just meant, yeah, okay, um I I kind of stuffed up here. Um so, just having that attention to detail and using that as your own reflection point is is important. If this is a place you're going into, um, start small. Do like just really cool little projects. Don't get disheartened. Just be mindful. Uh, some of the circuit boards that you might be printing will actually cost, uh, may cost a lot if you

don't have the resources. Uh, it it can turn into an expensive exercise. Um, small things are just as fun and and easy to um to play with. Uh, there's a couple, as I said, there's a few projects there that I'm working on. There's other ones I'm looking to expand into. Uh, but I want to get these couple working so that I'm like, "Yep, cool. I'm I'm comfortable and I'm going on this journey of just learning and having having fun." And that's what a lot of it's about. Probably my my last point here is one of digital junk. Um, I've probably done about five different prints and some of the hardware just doesn't work. For for me, there's like

uh yeah, I've got a lot of crap that I I now need to send off to metal recyclers that it's a little expensive. Um, and so I think this is also probably a wider issue we have within uh the technology community of, you know, we're we're creating a lot of hardware and that's also probably been something that's uh hit me quite hard. Um, but yeah, that's a cool couple of projects. Uh, how much time do we have? >> Not really enough. All right. Look, I'm I'm floating around for a little while. Otherwise, uh, I'm on LinkedIn. I'm on email. If you want to just jam on any of this stuff, you know, hit me up over

Google Meets, Team Meets, just grab my email. Happy to hang out and even just take you through some of the cool things I'm doing. That's it for me. Thank you.