Moses Parting the Sea of Traces

Welcome to the macro fat engineering podcast. We're your hosts, Parker Dohmen and Steven Craig, this is episode 99. One away away. Oh, yeah. Cheers. Cheers. Clunk. Alright, so this episode we're gonna be talking about using fr four or PCBs as like enclosures and structural elements in your project. Yep. Basically, because Stephen has been working on another synth, I think. I think he's got like eight synth designs going on at once. Yeah, yeah, got quite a lot. Let's just put it that way a lot. And so his new idea is actually just explain it, because I've only seen pictures of what you want to build. And so I can't really explain it. Besides, it looks like it takes a lot of space up. Well, okay, so

the, the last synth that I built, I did everything on a single PCB. And that was sort of a challenge and sort of just fun. But But what I'm really wanting to get into now is what's called Eurorack, which is modular synthesis. It's a standard, right? It's a standard. Yeah, so it's 128 and a half millimeters high, by however many choose freedom units, three you which is what's 1.75 times three, whatever that is, but it's actually easier to do in millimeters.

So in what, what, in metric, it's still a decimal of something. Yeah. What was that again? Well, 128 and a half millimeters. Yeah. So that was sent to me, I guess, you know, what's bigger than milliwatt? Smaller than millimeter? is one unit over

that. What's small? I think once you go lower than millimeters, you just get two microns, right? No, there's something out there. millimeters. It's not a decimeter. Is it? nanometers way lower? No

meter is? Negative nine. Six. That's Mike. That's Miko. Nine is nano. Well, the PICO Right. So there's minus minus two is centimeter.

Yeah, minus three is millimeter. There's a minus for a quadra meter. What's it called? Iris pulled it up here. Um, let's see. We are totally not metric. Guys. I've been on that list either. Because it goes from 70 to milli. So well, but then lower than Oh, it goes from million to micro. Right. Right. So so it goes from negative three to negative six, it starts jumping by threes after that, because it sort of doesn't make any sense to get more granular. I'm looking it up right now. Okay, regardless, I'll keep I'll keep talking about it. Okay, so. So this new synthesizers is basically every every piece of it is a single module. And so you build it in chunks, as opposed to building it all as one like I did. And DESE Milam deci milli. Okay, I'm never going to use that, because that's just what you said. It's 121 128 and a half. So it's 1285 doesn't really say so you're just you trying really hard to get rid of the decimal? Yeah, I mean, I'll put it this way is if you're going to use the metric system, at least use it properly, which is without fractions. Okay, well, that's not no, that's the biggest argument people having against the imperial system is you have to use fractions. To explain fuzzy you're gonna call people out. And so if you use a fraction in the metric system, you're you're doing it wrong. But it's just, it's just a naming nomenclature. That is Yeah. So it's all just semantics at the end of the day. Okay, well, 1285 decimal please. High or whatever, that is the height of one module or three u three u module. Yeah, they all have and that was kind of chosen such that they fit within a standard 19 inch three U rack. Okay. So it's it's sort of which is funny, because that is 19 inches, which is Imperial. So it's sort of a I don't know, you is a Imperial measurement as well. Yeah. 1.1513 quarters. Yeah. Got to have the fraction if you're going to go Imperial. Exactly. So, but But yeah, so each module can be they call them HPs. And that's the width. So it can be one HP which is I don't remember exactly how much that is, but they go up in integer increments. So it's like one to 40 HPs. So which, you know, can be up to a full panel with 19 inches. Okay, so you said 40 HPs is a full panel. So no Unlike the standards that you normally see only go up to about 40. They can go larger, but that's about what you normally send. So the thing is all of the different chunks of the synth that I made previously, I'm breaking out into individual modules. So the oscillator is its own module, the amplifier, blah, blah. So I'm building those all individually. And the thing is getting custom faceplates made for these modules is not cheap. It's like 70 bucks a pop. Yeah. And I want a lot of them. And so I picture it look like an entire wall look like an old mainframe, basically. Yeah, but it was a synth. Well, okay, so there's two different standards in the synth world. There's, there's five U, and there's three u, and five, u is the big module. And that's actually the one I sent you a picture of. I originally wanted to do that, but it's just too obscene. And I don't have room in my house for something that large and get rid of the couch. Yeah, and just oh, that my wife will love that. Yeah, the couch, we're gonna put a synthesizer. I, you know, I would actually probably do that. So yeah, but those little, they call them mug units and use or five years. And they're huge, which is cool for, you know, guys with fat fingers who want to play a large instrument, the size of a room, you have a lot more room, but they just, they don't travel very well. And they're harder to build and all that stuff, and cost more, and you route signals differently. That's right. So all of the each each panel has its own inputs, and outputs are each module I should say. And they're all done on either quarter inch jacks or eighth inch jacks. So the five units all use quarter inch jacks and the Eurorack or the three modules use eighth inch. And so you patch your connections all with patch cables. So the outputs from one can go to the inputs of any other one and use the brake instruments on the fly.

Yeah. Is the person called that plays this instrument an operator? Like a telephone operator?

You know, today? Probably I don't I don't know, you know, he might be actually called like a patcher, or something like that. I don't know the ins and outs of like, all of that nomenclature there. But that'd be cool. A synth operator what's like how a can a person who drives a train is called an engineer. Similar? Yeah, right. Yeah. Operator? Operator? Yeah. They just have an operator station. And that's your couch. Oh, and build it into your coffee table instead? So it lays down? That'd be sweet. Yeah. Or if like the top, like automatically opened up in there. And it was all Yeah, you press the button gas pistons go Shut. Up, I'll get right on that. Yeah. So one of the things with these modules, I wanted them to be really easy to build. I wanted all of the modules to have zero wiring. So I didn't want to wire the pots or two jacks or anything, because there's tons of pots and jacks, and you'd spend all day just soldering wires cutting like one inch long wires. Exactly. Yeah. And so you know, and yeah, that'd be a pain in the butt, right. So all of these things have to end up being a PCB stack, such that the, you know, the pots and the jacks all mount to a PCB. And then that fits through a faceplate. And they get mounted that way. So cool thing is their standards around that. So in the synth world, there's standardized pots and jacks that all sit exactly the same height of the board, such that if you buy that, you know, that family of family, everything works together. And it's super convenient. Because you really don't leave that family very, you don't have a need for it very often. Yeah. So you can build everything under one standard and you build like one footprint for a potential ometer and it applies to every module you ever make. And so it makes, you know, libraries and PCB super easy. But the back to the faceplate issue, I didn't want to spend 70 bucks for every module because you can have 50 modules in a synth easy, you know. So I was looking at what's an easier way and make the faceplate out of PCB material. Yep. silkscreen, silkscreen, and the most PCB manufacturers cut holes actually pretty accurate. In fact, way more accurate than I could do on a drill press. Myself and they come a lot cleaner. They, I can put any silkscreen information I want. If I want different colors of either silkscreen or solder mask, I can do that. So it was just kind of a no brainer. And with the fact that PCBs cost like nothing nowadays, yeah, just raw PCBs. It just kind of made sense. So I was gonna talk about that. Um, yeah, tolerance considerations. Yeah. On that's gonna be later on when we're talking about this stuff. So cool. Glad you brought it up. So yeah, as a structural material, you're using this kind of faceplate. Is there any like flexing concerns or anything like that? I guess it's since it's only like four inches tall. All, it doesn't have too much flex to it. Well, the thing is you are actually plugging things into it. So you will be putting force on it and your hands will be touching potentiometers and turning things. But that's really not too much of a concern because normal 1.6 millimeter, fr four is pretty stiff. Yeah. And, you know, if you had I don't know if you have it that Jack, I guess, like right in the middle of the board dimensionally then that would receive the most amount of flex. But, you know, when's the last time you tried to just break just straight fr for with your hand? Like it's tough? Yeah. So I'm not concerned about that guy. But we did see earlier this year, that Kickstarter for the, the CNC mill that's made out of Fr four. Yeah. And so it's apparently rigid enough to handle a little tiny, you know, engraving mill. So, you know, and it makes, it's not a half bad material for structural design. Yeah, we've used it for fixtures here at macro fab. Yep. Well, not PCB material directly, but getting like Gerulaitis G 10, which is really close to Fr four, right? Fiberglass epoxy resin stuff. Yeah. Yeah. The only thing that kind of really sucks in my mind is that some people are actually allergic to it. So if you get some fiberglass dust on you, some people will actually like break out in a rash. So it's kind of a nerd. I wonder what I wonder if it's like a physical reaction, then it might be the epoxy that oh, yeah, yeah, the epoxy. So it's, it's questionable. And at the same time, like you don't want to breathe in any the dust No, but I'm not doing any cutting. So I receive these PCBs like final product, and they're already cleaned and washed. So it's, there's no concern of that. But if you have to, like cut them yourself, or modify it yourself, then there might be a little bit of Yeah, I guess we could be allergic to dried epoxy, because I'm actually partially allergic to some epoxy brands. That when it's like I'm mixing it, but when it's dry, I never had a problem. And I wouldn't be surprised if you can grow an allergy to that or, I guess develop develop well, it's like when you you can develop an allergy for like, if you're a woodworker for like cutting pine, and mostly the harder woods that have like different Yeah, but it was crazy. You'll develop an allergy for the species of wood. Yeah, not for just like wood in general. Yeah.

Because like pine will just just sneeze like crazy. Oh, even Yeah, the

resin. Yeah, yeah, resin will just make me sneeze like crazy for hours and give me a headache. And it's not like I've tried like, oh, maybe it's just like dust now or one just a regular paper mask. And that's not enough. I had to wear a if I'm cutting that stuff all day, I had to wear like a carbon mask. Oh, yeah. So it'll get taken sucks. So, you know, one of the other things that's kind of nice about using Fr. Four is that it's originally intended to be electrical. So if you need to add any kind of electrical characteristics to the faceplate itself, you can do that for effectively free are already paid. Yeah. Plus the parts. Yeah, well, right. So so if you want to add like a ground plane across it for shielding, that doesn't cost you any extra, but if you want to do like touch pads, or anything on the front Mukhopadhyay capacitive touch, but you could actually do that. And it really doesn't cost you any more to add that on there. So it's, you know, there's some benefits to that. You can also get pretty fancy with silkscreen nowadays, because DPI is what 200 ish DPI at most. And motion some of them's actually higher than that. Yeah. So the the place that I've actually used for faceplates in the past, I used Ed EZ EDA, because they're $2 for 10. PCBs. Now, they're like $25, for shipping. So, in the wash, it comes out. Yeah, but at the same time, like, they do a decent enough silk screen that, you know, I wouldn't necessarily sell it as a final product, but it's totally fine. Being Yeah, yeah, for my own personal use. And so we're talking about, like, you know, putting electrical systems, I guess you would design this in, I guess the good thing about doing this kind of method would be you get to design it in the same EDA tool or design software, that you design your PCB and so you don't have to learn a new CAD software package, right. You could do all the artwork directly in your EDA and then output the Gerber, which you already know. Yep. And just do you don't have to find you know, figure out how to export a STEP file out of your CAD program or whatever. Yeah, so So for, for the the stuff that I'm doing right now. I actually opted to design the artwork in Inkscape. I did I did that separately because I wanted to choose like specific fonts and things like that. I went to da font because they have like 5 trillion and fonts and went to their like sci fi page. Because yeah, it just worked for since I've used the Blade Runner font, I considered it the Blade Runner and the Metal Gear Solid font I like both of those. They're both awesome but actually went funny enough I went with a font that was like on there like, most downloaded fonts page or whatnot, you know, cuz on those it's like a whole bunch of like really dumb cursive scripts stuff that says like Merry Christmas or something like that, you know, but they had one that was a really fantastic so I went with that. And I designed like a really nice, circular pattern to go around the pots to show, you know, zero through 10. I shouldn't even want to 11 Yeah, I should have. I haven't bought it yet. I haven't bought it. Maybe I can just go back. But but so I did that in Inkscape. And since I did everything in dip trace all the PCB design, I can actually upload images to silkscreen in dip trace. And so I just exported with like 5 billion DPI and just pumped that right into dip trace and it comes out 20 megabyte Gerber file. So yeah, it comes out looking pretty good. I'm happy with it so far. Awesome. So yeah, hopefully in the next, I don't know, a couple of days, I'll place an order for a handful of modules. And when it's all done, I would like you to play it. Especially I think that would be a lot of fun. I've never played a synth before. So besides turning knobs on the one that we built, right, you built you, you I would boil this thing on the enclosure, you did the least electrical part of enclosure. So you know when this one's when this one's done, it's a lot more like tactile to play. Okay, because you actually have to like, connect things physically. Yeah. So I want you to play it. And maybe we'll have another synth jam on the on the pocket. I got a question about those Eurorack things are the cables shielded? We'll show there. It's just a conductor. So it's one is signal another one's ground. Yeah. Okay. So they are shielded? Yeah, yeah, they okay. Because that's one thing I was thinking about is like, if you were if you are manufacturing these things.

How do you get would get those FCC certified? Because there's so many different configurations.

To basically use one of those Eurorack modules. How would you, you'd have to test for per FCC rules, you have to test every single way I think could be hooked up. Ah, I'm not entirely sure. And the thing about it, too, is like those outputs, even if you don't have a jack plugged in, most of the time, they're not shorted to ground. So though, they're just acting as an antenna. Yeah, but I mean, most synth don't go above 20 kilohertz. And most of them are analog, and they don't have a processor buzzing away. So the thing is six kilohertz is what has to be under. Well, yeah. So I mean, the thing is, probably so low power, it's not broadcasting. It's high voltage, low current. Yeah, it's usually 10 volt peak to peak. But like nothing current. Yeah. So I don't know what the rules would be for consumer audio equipment. Eurorack.

Yeah, I don't know, either. Or would you try to, you know, sell it as a test equipment thing?

Well, and that we, I don't know if you could certify it as that I don't know anything. That's craziest. Most most cases that people put these Eurex in are made entirely of wood, which you can't do that either. Yeah. I mean, they're like screwing power supplies, directly into wood, like three amp 20 volt power supplies, in directly into wood. So I don't know how they get away with it. I mean, obviously, home gamers can do whatever the hell they want. Yeah, but

yeah, I don't know. Maybe I'll look into that. That'd be fun. Yeah, see, go to like one of the major manufacturers or your racks up and see if they have FCC stamps on their stuff? Uh, yeah, I doubt it. Cuz I'm just thinking because even if you could, like shielded and stuff, like that's, let's say, it's fine. It's just all the configurations, you'd have to put that device through

that tested, get it tested, if it's connected to this thing, or they just connect wires into it, and just leave the wires out. And just say, that's like, the worst case scenario is, the wires are hanging just plugged all in? And they're just antennas, basically, well, you could do that or come to think about it. If you were say, if you were designing all the modules, you could design every input to having known specific impedance, such that you could plug every output of a module into an impedance box. Yep. And then that would count. They would they would let you get away with that. Probably. Yeah. Yeah. So but I mean, the thing is, since it's user configurable I don't think you I think there's exceptions to that when I think I because because you were talking about this thing, but didn't You can also apply this to like PCI cards and video cards and computers. There's so many different configurations like that video card can plug into 500 Different motherboards that are on Newegg. It's like you have to test each of those configurations? I don't know. No, I The answer is no. The answer is no. I know that for a fact. And in fact, whenever I've done this kind of testing, the majority of the way it usually works is that you put it in what is known to be a standard standard specification verification, such that it meets whatever the data sheets, typical values are, and you let it run that. So you probably what you probably do is, I bet you these, if you buy a professional Eurorack, that's got the stamps and stuff at bench, if you went into the datasheet, it would have the like typical input values and output values. And then they basically make sure that when they're running the tests, and they do the conducted emissions, it still does that. Yeah. Yeah. That's probably how it works. Yeah, I don't I don't, you know, the, the, the conducted is a lot different in this case, because there's so many different inputs and outputs, you'd have to, you would have to test it with a wire independently in each input. You couldn't have wires to all the inputs, you'd have to do it like one at a time, I think, yeah. The radiated, I would think would be a lot less troublesome just because they're lower power, low power

stuff conducted would be a bitch. Maybe we should try to find a company that's got those certs on their stuff. And just like, maybe interview them on the podcast,

that'd be cool. Yeah, I can I can reach out to some people. Or if you're listening right now. No. Oh, my gosh. An email at podcast at Mack Fred calm. Okay, cool. So, back to Fr for as a structural thing. Yeah. I've mainly used it as like for prototyping. For like doing enclosures for, you know, test jigs and stuff like that. I haven't really used it as a end product yet, mainly because I had a guess I've had access to like 3d printers and stuff. So I'll make like an enclosure out of that. But I have used it for like, touch capacitive stuff. Yeah. So I should try to do more of it. You know, you know, one thing that it actually works really well as in fact, Dave Jones did this for his microcurrent you can purchase a box that just has one face missing. And then use the naked lids. Just a lid? Yeah, and because then you can mount the entire circuit to just the lid and you screwed in once. So you still have a box that looks professional in terms of the outside of the box. But the faceplate itself is fr for material works real well for that. Yeah, that actually, that solves a lot of problems with like mounting switches and stuff, right. And then if you if you really want to get fancy, and you need, you know, a certain IP rating, you could put a gasket on it. And it would still probably work fairly well for you know, the lower rated ones. Yep. So yeah, it's a it's really cheap. Yeah. Cool. Well, you know, actually come to think about us electrical engineers are the probably the only people who consider this as an option. Yeah, often because we just like it fits within our wheelhouse, like we know how to design it. Yeah. You already know how to design it. It already works with your toolset, you already know how to order it, and you already know how to order it. Yeah. And you know how, like, the properties of it. And you don't have to talk to anyone or give them a drawing. Yes. Like you just click Order and it shows up. You

just send them gerber files. Yeah. shows up at your cave. Yeah. Okay. All right. Cool. So go on to the pow pic of the week. Hmm. So this one was a Brian who emailed us in he's the farmer poetic.io. I don't know if that's important or not, but it says here on the sheet.

He asks, Do you? Do you have a guy that knows lots about sensors? I think we know a little bit about sensors a little bit. I need one that will tell me the distance to any solid object out to arrange about 60 feet could be ultrasonic, but I'm not sure if there's one strong enough. So I was thinking about this question. And I actually stumbled upon today while I was writing the notes for this podcast. Have a sensor that's a 24 gigahertz radar sensor that goes in like cars for distance sensing for your You're like speed control for the cruise control. Okay, auto distancing and stuff. And it's evaluation kits. You can just buy this. Oh, wow. Okay, the other contact a company to get it. But they're like it's a, they have it listed under standard products. So you probably have an on the shelf. Yeah, they have one on the shelf, and you probably just call them up and buy them. It's the K L D to eval. If you Google that, they'll pop up. It's by Rf beam. Okay. You can probably use an ultrasonic sensor. The problem I've had with ultrasonic sensors is when you get to a certain distance, it's really hard to aim them. Oh, yeah. Yeah, they certainly they have a cone. Yeah. And really ultrasonics don't work well. After like, two feet. Yeah, they kind of drop off real fast. Yeah, I think I've used them up to like six and a half, seven feet in. It's been okay. But yeah, that that radar, I kind of want to get one just to like, see how it works. It's got like a really interesting Web. NET web GUI, like just a computer software that you connect to and see how the sensors working and stuff. So did they say how much it is? Unfortunately, no, I tried to look. So it can't cost more than a couple 100 bucks. I don't think No, something like this. Probably a few 100. Yeah, not too much. I don't know what kind of price range Brian wants. But I mean, he can try 20 bucks. He's talking probably an ultrasonic sensor. That's like $1. So So I was looking into something that's similar to this a while back, because with my CNC table, I wanted to have like a Dr. O on the table, which I can tell where it was at any point in time. But up to the full four by what's a Dr. O digital readout, or run out indicator, do not run out. And but it's it's it's a digital read of where the devices like Mills, CNC mills typically have them lades, which is 1/1000 of an inch for you better people. I meant like a milling machine. Oh, but but they read mills. Yes. They read mill, the mill will read mills. Yeah, is. But the so I was looking into doing this. And I first I was like ultrasonic sensors, could I do that. But the thing is, like I wanted to read, really honestly, I wanted to read down to about five mils or five one thousandths of an inch across eight feet. Yeah. And that's really hard pointing a laser Well, and that's, that's what I was really actually going towards was if you shine a laser and reflect it back, and you look at the face change, like basically like a sine wave change, you can actually check the the phase difference between the laser that you're sending and what you're receiving back, and then you can tell the distance, but that's based on the wavelength. And so you'd be traveling across gazillions of wavelengths as you go across eight feet. So you'd have to have some kind of like, weird counting software. And it wouldn't be absolute. It would always be relative in that sense. Yeah, you'd have to have an FPGA. Yeah, yeah. And these they would work like an encoder. Yes. If you just shine the laser. Well, then how do laser distance finders work? They post the laser then? Well, yeah, I mean, that's, that's how it works. You pulse it and you get you get a phase difference. Basically, how the ones work that no absolute distance, then? I don't know, I'm not entirely sure on that. I've maybe they just post and see how fast the laser gets back like a radar gun. It might be something of that sort. Yeah. Because well, okay, so I was working in the vibration industry a while back. And that was one of the things we didn't do it ourselves. But we looked into the technology of if you shine a laser at something, and you look at it returning, and then you look at the phase jitter you can actually see something vibrate without actually touching it. Yeah, that's how temperature laser temperature sensors work. Yeah, yeah. Right. And so you know, we were looking into that. And I was like, Can you do that across the larger distance, but it's actually not that difficult to do when you're talking about a distance of like, you know, a 100th of an inch, but across eight feet is really hard. And 60 feet even harder. Yeah, I'm wondering, actually, the easiest way to do that would be to get a really high resolution camera pointed down, and then a like little tiny.on top of your spindle. And it just did. It just looked at it that way. No, no, my work. Yeah. So they just hit zero on your machine. And it zeroed out and then or if I really wanted to do it, I could just put encoders on my saying yeah, yeah, I just read that but yeah, but that's like the easy way to

kind of like the the computer vision way that my work pretty well. Yeah, you just have to have a really flat vision flat field.

Oh, no, no, you just use a really high focal length. Yeah. Okay. And then it would and then you use parallax correction and be fine. What you could do is actually mill out and your table, a ginormous grid to correct the parallax. So Oh, mil a ginormous basically checker grid. Yeah. And then move the arm away, and then the camera takes a picture, and then you and then it would readjust itself to that grid. Yep. Yeah, you could do that. That's actually built into open CV, it'd be that would be interesting to see what kind of like, absolute accuracy you could get. Considering all of those factors. Yeah. Would it still be only accurate to like a centimeter? I have no idea. I guess you'd have to look at the resolution your camera? Well, yeah, that would probably dictate, and that that would dictate the most of it. Yeah. Basically, whatever pixel per pixel per, or distance per pixel. Yeah. The Yeah, that's what it is. It's dpi. Basically, how many pixels per inch? You're running? Right? Damn, you'd have to have a pretty solid camera. Yeah, I'm pretty sure you actually wouldn't even have to use Open CV, you can actually just like, look at it, because if the camera didn't move, you would just look at where that.is In the field. And then that pixel is this number. You know, funny enough in my first lab, in physics, college physics, it was a, I took it my first freshman semester, we actually did something pretty similar to that. We had these in the lab with these cameras that hung from the ceiling. And we had these like trolleys that fit on a tray, like a like a cart, basically. And it was like an air hockey table. They ran on a cushion of air. Oh, yeah. Remember this lab? We had same lab? Yeah. At UT. They had the same Yeah, similar. Works lab is probably similar ish. But you would like move the cart, it would hit something you would ricochet off, you would measure its mass. Yeah. And then if you if you looked at the camera or the video feed from the camera, you could get timing and how fast it was going. And then you could basically rally around a bit way of not using a scale o scale in a stopwatch. Yes, that's basically it was probably the year before they probably gave kids a scale on the stopwatch.

No, no, it was a way to basically reinforce that physics is a real thing. Well, yeah,

no, it was Yeah. It was like proving, really, it was like weeks and weeks of proving F is equal to ma. That No, that's what it basically yeah, yeah. And all the formulas that are derived from it. It's like when you take your first like computer, electronics lab, it's like the whole year is proving you know, V equals IR. Yeah. Which that's everything for electrical engineering is practically Yeah, cuz like the first year and let's go engineering you do. Ohms law and you do kerchiefs. Kirkup. Heracross law, which is like the node, amperage and voltage and the current. Yeah, yeah, the voltage at every point is the same. And then on the same net, yeah, on the safety net. I like that. They didn't teach it as a net. But after you leave college, everything is a net everything. Yeah. And then all the currents that flow into a net must also flow out of the net. Yeah, man, they hammer that in? Yeah.

That was like, 14 years ago. I still remember. It's stupid stuff. I don't use that stuff every day.

When Okay, here's the thing. No, did you know you do use it every day? You absolutely use it every day. But the thing is, but you never have to like do any of the calculations. It's like you have proven to yourself and to many professors that the voltage at on everywhere on one net is the same that's proven it so many times that you just believe it. Yeah, it's becomes a rule of thumb. It's you rule out right and you know, all the current flowing in must also flow out. So you don't have to prove it to yourself. You just know it. Yes. No, that's true. That's true. You do use it. It's just the way they teach it. It's just like, oh my god the same homework problems over and over and over. Yeah. The this everything on the left side of the equation must be everything on the right side. Yeah, it's funny. We're recording this too right now. And there are students that are suffering to the final exams right now. Oh, doing kickoff. Yeah.

You know, okay, what's, what's the one with the it's the digital it's a digital logic class, but it's like we have to draw those grids.

Oh, I'm calling Karnaugh maps. Oh, K maps were the worst 3d K maps 3d K nap K mats? Oh, yes. Oh, I hate K so our our class when we did that was digital watch intro to digital logic. It's like 316 or something like that came out with a number. It was a self paced class. Yeah, that's right. UT had that where you had to you just showed up and that was it. And then you just like scheduled to take a test or quiz and then and there was like on This state you had to make sure your first midterm was done. And this was your second midterm date had to be done by then. So I failed it my first year. And the second year I finished it in the first month. He didn't rip. I just rip through. I've raised the sat down just did everything. Wow. Yeah. Did you can make an A Yeah. Basically, I took too many classes the first year. Oh, the that semester. And I just didn't have time. I basically just blew it off because I was a college student. And yeah, that's happens. I hated I knew people that failed. Because they failed that class twice in a row. They got they dropped out electrical engineering because their class because they couldn't manage their time. Yes. Wow. Yeah. That's next

day. I think they made that not self paced like couple years after I took it. Because so many people dropped out because

of that class. Imagine if every class was that way. Oh, I would not graduate. I can take a term when ever. Yeah. That's never gonna happen one hour before the do. Oh, shit. I gotta take

them. Like, you show up to do the midterm. I like the day of and it's like, we're full. Shit.

There's not enough desks to do it. Now that's great. Yeah. So Brian, go check out the k dash L D two dash eval. And actually let us know how much it is after you get through salespeople. Yeah, I want to pick one up and pick one up for us to Yeah, ship it to

podcast that macro.com will send you a t shirt digitally transmitted to us. Or if you're from our beam, send us one and we'll send you a t shirt.

That'd be cool. Now, I think if you have like 20 3040 How many people are in that company? You have to share a shirt. But

I You know, honestly, for 24 gigahertz, I would love to open it up and take a look at that. Yeah, so the transmitter would probably pretty cool. Look pretty cool. Okay, yeah, I had a landlord once where he, it's it. This is a weird conflict of interest. I don't know how this works out. But he's a cop. But he also has a business where he repairs all of the police's equipment. So there's there's a weird conflict of interest there. I don't know how it works. But he did all like kill switches for for cameras that the body cameras. He puts a kill switch in. I bet you he did. Yeah, I would not be surprised. I used to go over to this guy's shop. And we used to just drink and play with radar guns all the time. It was awesome. And it was cool. Like his shop you it was it was so completely random. You would walk in to his shop. And he had a case there a glass case like he, you know, you see at a store. And it had half of it was vacuum tubes. And the other half was bullets. And he always always had a whole stock of Bush beer. And he would just crack open Bush beer and we'd play with radar guns because he fixed radar guns. He ever tell you what tolerance he would have to calibrate those two. He had? Oh my gosh, he had a room that would make you drool in terms of like test gear. Yeah, so we had all that stuff. The thing is like, Man, I swear he did have this stuff drunk. So I don't know how calibrated. All of it was. He was he was a fun dude. And he had like, 8 million stories. So like, you could sit there for hours and just listen to this guy. And he taught me how to change the text on like road signs.

I'm actually thinking like, what, like he knew like the secret technology to put in front of your car. Yeah, right. ogron would just bounce off. It's just a text file. There's just a laptop. Not like, not get pulled over for speeding.

Oh, yeah. I mean, he, you know, the funny thing was, he, the guy was obviously a beer drinker. And he told me he's like, I never send a guy to jail for a beer for driving drunk. He's like, I don't do it. Unless he talks back to me. Unless he gets he gets mad at me. He's like, I you know, I can understand you went out and had a couple drinks and you're driving home. I get it. I'm not gonna pull you over and do that. He's like, but if you give me back talk you. Also we do not condone drinking and driving. No, no, we did not. We absolutely would not. The funny thing was he told me this one time. He's like, he pulled over a guy for for drunk driving the other day and he goes, I'm gonna give you two options. You can either go to jail, or he can grab the guy's phone and he found a girlfriend's phone number. He's like, I'll call your girlfriend or you go to jail. You pick. A good option isn't pretty good. Yeah, good. Yeah.

So there you go. That's here's here's to you, Larry. Like it's like the most generic name. Oh, yeah. Larry, wherever you are, Larry, here's to you. We had some fun,

hopefully in a maybe not in a ditch somewhere because he was drunk driving.

Oh, man, we should not be locked. Onto the ark. kinda lame this week because the week this week has been well,

I see they're about equal. So they have to be laid. Yeah. And it's also it's just like it's right before Christmas. So like, most engineers are like, you know, with their families not doing anything cool. We're gonna really find who the true listeners are this week. Yeah, exactly. So yes, eagles, the first RFO Eagle 8.5 came out. And they introduced push pull, shove routing. Okay, that's awesome. Yeah, so key cats had his whole wad. Well, the stable releases of KY CAD has doesn't have

like a, you have to call it stable. This the CERN release, because, you know, CERN is like the, the, the people who smashed particles in Europe.

They have their own like repository for KiCad. And they do their own development for it. And they have push shove routing. So eagle has 8.5 has pushed up routing. Now. I upgraded today, it's pretty cool. It's actually really nice for when you need to add stuff. It's not really I don't think it's really useful when I'm routing the board from beginning, it's when I need to add something in the later revision, like I need to add this chip, or I need to change the routing to this or like the pinout or something. Because then instead of having to rip up a whole section of the board, to reroute one trace, I just kind of push the trace through and everything is like Moses party in the sea. You know, one thing I found that actually makes really good traces. There you go. That's the title. So So I've actually had do this in the past. And it's super convenient with push of routing. If you have a connector with a gazillion lines that come off of it. You it's nice. That's like them all like 10. Lisa, like the 20th. Right? Yeah, and I've totally made boards like that. But no, I had one where I had at least like 20 lines that had to go from a connector to a processor. And the connector was on one side of the board and the processor was in the middle. And it was it was like two or three inches. To get to the processor. Well, I You what I would do is I would add a line and then add the second one. And I would just push them up against each other and they would auto space each other. Third one would just you as you keep adding it, they would automatically space. And if you wanted them all to have that nice like all of them followed that nice 45 Look. Oh, yeah, just push on the 45 then they would all just stack up. Yeah. And that's super nice to have that automatically done. Yeah. So I can't wait to actually get no, use this. I like tested it out and like Okay, that's cool. Yeah, but when I actually finally you'll sit down and like, and actually use the tool and appreciate it. You go Yeah. And so also in the so also an EDA tool holders Altium, designer 18 came out. Neither of us are Altium users. I did download the demo, and are trying, you know, trying it out to seeing how it's like and I still can't really get used to it. I'm just different. Yeah, it's like any EDA tool. I was designing boards and just trying it out. But it's just so I just it's weird because I'm like the only person I know of that like actually likes Eagle. It works like an old school EDA tool. And that's why that's why like, I think I think that what you said right there is exactly why people like it. And exactly why people don't like it. Yeah. So I think Altium won't give me demo copies anymore. I I've gotten so many. Remember, we switched dotnet to.com For Oh no, I exhausted that too. Oh, gosh, no, no, no, no. Like every email address. I've used other people's email address at macro fab. I've gotten so many copies. And, and, and maybe it was a newbie move, but I use the same phone number every time. And, like 50,000 times. Yeah, it's like this is like they call it like, you'll get like eight calls in a row from the same person. Yeah. It's funny. I Parker's heard the story before. I don't know if I've said this on the podcast. But there was a salesperson who called me from Altium. And she sounded young and the way she was talking, made it seem like she was fairly new at the place. Maybe she wasn't I don't know. But regardless, like she was, she was a little shaky when talking to me. And I was like, Hey, I literally she like she was trying to talk about Altium I was like, Hey, hang on, hang on. I was like, I'll give you 200 bucks right now for Altium. And she like it. She just was like dead silent. I was like, Okay, that was a joke. Call me somebody

I don't know what I would have done if she was like, Okay, let's do it. You know, give her $200 or 200 bucks and get Altium Yeah.

Really good deal. amazing deal. Any other Ouroboros you can think of that's in the list? Oh, I guess thumbs up an oto meeting. I don't know what that means. But thumbs up. Yeah, apparently is a big rewrite of a lot of the software. So, oh, okay. Yeah. Cool. Well, we talked about the dip trace 3.0 A couple months ago, right? Yep. 3.2 CAD is still on four points, whatever they're on now. Yep.

I think that's all the big ones because all the other ones like our, like cadence and stuff and their heads pads. Yeah. Yeah. No. protel No. Okay. ProTools Altium. That's right. That's right. Back in their mid 90s. Yeah, it started as proto Yeah. Cool. So that was the macro. We were done, right? Yeah, sure. So that was the Mac of engineering podcast. We are your hosts Parker Dolan and Steven Craig See you next time for episode 100

Take it easy Thank you. Yes, you are listener for downloading our show. If you have a cool idea, project or topic that you want Steven and I discussed, tweet us at Mac crab, or email us at podcast at Mac fan comm also check out our Slack channel. If you're not subscribed to the podcast yet, click that subscribe button. That way you get the latest episode right when it releases. And please review us on iTunes. It helps us stay visible and helps new listeners find it no press that button yet, because we also have a position open on our software team. We need someone with strong Linux and AWS experience to build the tools we use to test build, deploy, and troubleshoot the software that drives our Mac fab platform. There'll be a link in the podcast description of where you can go check out our job postings.