Before we get started I would like to thank everyone that entered into the MacroFab Design Contest: Blink an LED Sponsored by Mouser Electronics. The judges are going through the entries this week and we will announce the winners on the blog and typical social media locations on September 17th, 2018. Stephen and Parker will announce the winners of the MacroFab Engineering Podcast Favorite on the next episode 138.
- Software Defined Radio update
- Python on the Raspberry Pi talking to Arduino
- Software Defined Radio update
- Simulation of circuits
- Do you use it?
- Should engineers do more simulations?
- KiCAD Schematic Symbols from PDFs
- KiCad Interactive HTML BOM
- Samsung Caps? Counterfeit parts rampant?
- James Lewis from Slack – “Established brand name, new to the market, and famous for being the cheapest. It’s a thief’s dream.”
- Simulation of circuits
Visit our Slack Channel and join the conversation in between episodes and please review us, wherever you listen (PodcastAddict, iTunes). It helps this show stay visible and helps new listeners find us.
Special thanks to whixr over at Tymkrs for the intro and outro!
About The Hosts
Parker Dillmann is MacroFab's Co-Founder, and Lead ECE with backgrounds in Embedded System Design, and Digital Signal Processing. He got his start in 2005 by hacking Nintendo consoles into portable gaming units. He also runs the blog, longhornengineer.com, where he posts his personal projects, technical guides, and appnotes about board layout design and components. Parker graduated with a BS in Electrical and Computer Engineering from the University of Texas.
Stephen Kraig began his electronics career by building musical oriented circuits in 2003. Stephen is an avid guitar player and, in his down time, manufactures audio electronics including guitar amplifiers, pedals, and pro audio gear. Stephen graduated with a BS in Electrical Engineering from Texas A&M University.
Host 3 00:10
Hello, and welcome to the macro fab engineering podcast. We are your host, Stephen Craig and or good omen, and this is episode 137.
Host 2 00:18
So before we get started, I'd like to thank everyone who entered into the McWrap design contest Blinken, led sponsored by Mouser. Electronics, the judges are going to go through the entries this week. And we'll announce the winners on the blog in the typical social media locations on September 17 2018. And also Stephen and I will announce the winners of the macro engineering podcasts favorite on the next episode, which will be number 138.
Host 3 00:44
Yeah, stay tuned next week for that, that one's gonna be a lot of fun because Parker and I are going to come kind of a little bit of preparation between the two of us separate so we kind of get to argue about which ones we like. So who knows, either, we'll pick different ones that we like, and then have to argue about it. Or maybe we just have like a really simple consensus, and we go with that. So I think it's gonna be a ton of fun. Yeah, it's gonna be great. And and I've been keeping my eyes on all the projects as they've been coming in. And they're awesome. There's a bunch of really cool stuff. So I'm looking forward to it. So Steven, yes, sir,
Host 2 01:18
What have you been working on? So stuff kind of stuff.
Host 3 01:24
Mainly, last week, I actually announced to everyone that I had opened my new website, analog nj.com. That's analog emg.com. But as of last week, it was pretty much blank, there was nothing on it. So as of now, there are two blog posts up on my website. So I apologize for how kind of rough the website is, it's still kind of in the mix. And I will be dumping all of my projects, personal projects, Makerfaire, projects, all the kind of stuff I do, I hope to eventually just move it up onto that website, similar to Parker's website, which your website is what,
Host 2 02:00
One, one engineer.com.
Host 3 02:02
So I've got two blog post up about my micro tracer project. The first one is kind of an introduction to everything, just an overview of the whole project. And the second one, the second blog post is mainly about, you know, starting to dive into the circuit design. I wasn't sure exactly how deep I wanted to go. Go ahead and go read those blog posts, please ignore the grammar, or the lack thereof, because I'm an engineer and not a writer. So yeah, go check it out, I will have a third blog post talking about the code, which that's going to be the scariest one. But that'll come out, eventually, we'll see. So hopefully, I mean, the plan is to as I go along all of the ideas that I kind of dump in this podcast, and all the little like side projects I do and things, I want to just have more of a open repository and you know, a place where people can actually view these kinds of things. And hey, you know, maybe someone will get enjoyment out of it. So check out analog emg.com. That's one of the things I've been working on.
Host 2 03:05
Yeah, I can't wait to you get more your projects up there. Because I know you have many, like most engineers do.
Host 3 03:10
I've got, I've got a ton. And I really, so I'm currently currently in a house, still kind of like apartment hopping right now until we get a house up here in Colorado. Once I get a house and I have my basement dungeon layer or whatever you want to call it, I want to have a lot more dedicated to making the website great and providing good information and potentially videos and a lot of other things that frankly, I haven't just because of my living situations in the last few years, they things like that have just been difficult. Once I have more of like a true home base, I can actually do a lot more stuff like that. So but as you know, as I build up to that, I hope to have some, you know, lengthy blog posts, kind of like the ones I just did with the, you know, that are a little bit more meaty, and into the design of projects. And also some more simple ones. Like, I believe last week, I discussed recapping power supply that I have, I'd love to just kind of have a blog post about that. Just something pretty simple. Well, it's actually kind of similar to the blog you have where there's some things that are I visited yours the other day, there's there was one blog post that you had like 50 pictures on one blog. And then and then there was another post that was just like, hey, I did this.
Host 2 04:27
Well, I'm looking at it as a Yeah, no, what did I get done? Yeah, you know, that weak kind of way. And so sometimes it's like one picture or nothing. And it's like, Okay, I gotta come up with something to post there.
Host 3 04:39
Yeah. And I want to get better at, actually I want to get better at doing a little bit of photography, taking pictures of small projects and electronics and things like that, which is something I've frankly never really had the desire to do. So I've never really spent any time learning how to actually take a good photo. So I'm kind of happy The beginning journey of that, and I know that's like a super deep hole I, I've had plenty of friends who, you know, they they spend their entire life savings on on camera equipment and things and I don't want to be that. But I would like to get better than my current skills are.
Host 2 05:15
Make sense. I always want to my biggest problem with taking pictures of like circuit boards and stuff is the glare that you get. So I think I think I want to go your route and get a light box because those look pretty good. The pictures
Host 3 05:29
On my blog? Yeah, yeah, yeah. And and I got it, I got a light box off of Amazon, I think it was 50 bucks. And I went for the $50 one as opposed to like the $30 one because it The box itself is two foot by two foot. And a lot of projects that I have our guitar amplifier chasse ease that their width is like 22 inches. So most of the other boxes are like 18 inches or so it'll be like boxes, I mean. So it's like if I ever want to take a picture of an amp chassis, which I have like, swear to God, I have like six in the in the works right now. And I mean, my fingers, you can't see it right now my fingers are super cross once I get a really nice basement that I can just kind of like close the door and become a hermit and work on my electronics, I will have all of those work.
Host 2 06:21
I remember when we moved all your stuff, or how many amplifiers we had to move,
Host 3 06:27
There was nine boxes that each each box contains its own amplifier. And those were the ones that I wanted to keep nice. So I put them in a box. There's many other amplifiers that are floating around in plastic boxes here in there. So you know, and I was playing around earlier this week with the idea of some solid state amplifiers. I've found some really nice chips I took off the top my head, I don't remember what they are the part number I mean, but they're they're Class D amplifiers that could do 100 Watts, with no heat sink whatsoever on a two layer board. Mm hmm. It's just it's amazing that these chips can do that nowadays. I mean, 100 Watts, I betcha the TI part. It was yeah, it was absolutely it was. Yeah, it was one of their, they call it a digital amplifier. Which to be honest, I don't know that world super well. So those are probably been around for a while, but I had just haven't researched them too much, mainly because that that style of amplifier, just the consumer style, you know, Speaker thing doesn't really apply to most of the stuff that I do. But I've been asked to play guitar at that my local church. And I was thinking man, it might be kind of fun to build a little amplifier for that. So I don't know, it might be kind of cool. Tubes not
Host 2 07:51
Good enough for Jesus.
Host 3 07:55
Well, tubes are locked away in a storage facility right now. And you know, the funny thing was, I think I either gave away or sold. Practically every amplifier I have that worked.
Host 2 08:12
I only kept the ones that don't work while I'm doing a little green one, the OG
Host 3 08:18
I'd still have that one and that one does work. In fact, I can't get that thing to not work. I haven't read tubed it in so many years, and it's just been abused isn't the right word, but used heavily. And it just keeps going. And it looks like garbage on the inside. I mean, it was the first big electronic project I ever built. And I had no clue what I was doing. And it still works. I love it. I don't know, there's a lot of tangents there. Go check out analog nj.com.
Host 2 08:49
Maybe Steven will have a tube amp built by then
Host 3 08:52
Yeah, hopefully, that'd be cool. I have I do have some, I actually got some really cool stuff that hopefully will make its way onto the blog. In the future, I want to do some tests with different ground schemes inside of amplifiers. And so when I actually get the chance to have like a true Workbench where I could play around with that, I want to actually take some measurements, instead of just like telling someone, this is the correct way of doing it. I want to actually like evaluate some grounds games, which that's a big thing. You know, it's you know, it's not like you, you just whip up a board and change one thing and measure it with a scope, you actually have to like, physically wire, you know, 10s of items, sometimes like a few 100 items, and then measure it all, you know, so I'd love to, I'd love to actually play around with that and see if I can get something that actually makes sense.
Host 2 09:44
It would be great if you built by how many different ground schemes you have and just built three identical or four identical amplifiers and the only difference is different ground schemes between them. And then that way you can A B C, D Whatever test them,
Host 3 10:01
That would be super cool. Super, super cool. That seems really difficult and expensive. But, but that that would be a lot of fun if somebody wants to help fund this. Yeah, I don't know. I'll figure it out. There's there. I do have one amp right now that I built a long time ago that I know, I used what I would call a sub optimal groundskeeper in, I built it more. The reason why I built it that way was more time than it was like quality. I want to go back, I want to rip all the grounds out. And I want to redo it in a very, very, like methodical and laid out logical way as much as possible. And see if I can get rid of some hum and buzz that's in it. It's really, it's really not that bad. But I've I've heard other people who built this exact same amp, where it's better. And I just want to see like, can I make? I don't know. 2030 changes and have it be like very noticeable difference. And I think I can. Yeah, so, so many cool things that come up now be cool. And effect. I've got it got another little thing. This is actually not necessarily my kind of project. But something showed up at work today. That I think is super cool. So there's a there's a guy who kind of he's a little bit of a contract worker that works for WMD. Or works with WMD. He he a long time ago, purchased a Vectrex. Which you know what a Vectrex is right, Parker? Yeah. So
Host 2 11:31
Yeah. vetrix is one of I think it's actually the only vector based video game home console you could buy.
Host 3 11:41
That's right. Yeah. In a nutshell, it was like a consumer grade oscilloscope with a game in it. In effect,
Host 2 11:49
Correct? Yeah. They explain what a vector is. So a normal TV and your normal LCD monitor. And how normal games are rendered, is it's line by line pixel by pixel going from left to right, up to down, right. And so that's how it's drawn. Whereas a vector display actually is jumping from point A to point and as the line moves, or the the, the beam moves it, it doesn't really draw a line. It's the phosphors fading, right? It's similar to a CRT TV, where has the raster line, that line is going left them right up, top to down. And it's the the fading of the phosphors that illuminate but it's a different way to control the beam, so to speak.
Host 3 12:37
Right, right. And and the way it's set up there, it's actually uses, you know, XYZ kind of 3d coordinates where x is left and right, y is up and down. And Z is brightness. But in terms of the way of thinking of that with this kind of tube is it z is almost like distance from you. Yeah. So it's more of like how powerful the beam is. So it ends up being brighteners. But regardless, they use an XYZ kind of scheme to it. So a Vectric showed up at work today, because one of the guys wants to mod it. To use it with his modular synthesizer. What he wants to do is he wants to install jacks on it sets a he can punch his audio wave into the XYZ signals, and basically visualize what he's playing on his synthesizer. In other words, he's making an oscilloscope where he doesn't necessarily care about what the scale is, as long as it just shows up on the screen
Host 2 13:34
Output this way, though, it'd be way easier if you just bought a old Tektronix scope online, like on eBay and it put that in XY mode and just pumped in
Host 3 13:43
Signals. You know, what's funny? You're right, and you're wrong about that. The you're right as in like, yes, you could just pump in signals with that, but the part where you're wrong is it's not necessarily easy. So get this I when I heard about this project, I was like, this is super freakin cool. I absolutely love this. And the fact that there's a guy who went and bought this old ancient video game thing was I love it. Oh, by the way, is kind of side note, one of the one of the selling points originally of this device was the fact that it was like an all in one it was you got the screen, you got the controller, you got the game. And they kind of sold it that way against other game consoles at the time where it's like you don't need a TV it is a TV you know kind of thing, which I think is super cool. But check this out. The the service manual is still available for this guy. And we'll we'll provide a link to the service manual on page 32 of this service manual.
Host 2 14:40
I'm going to open up this thing okay. Yeah,
Host 3 14:42
It's actually called the power board schematic. But on this board, it's basically you know, the like the flyback transformer and all this stuff for driving the CRT along with the the actual power supply, but what it has over on the left side is where all the xy z signals come in to the board. And it's basically just a Molex connector. Actually two molex connectors. One of the molex connectors has the X and Y signals on it. And the other one has the z, which is basically brightness. Like I said, what's kind of great about this? Apparently, people have already done this before with synthesizers and the Vectrex. Basically, are ready to scale with standard modular synthesizer, signal strength and signal amplitude, basically. So all you have to do is pull this MOLEX connector out and plug your wires directly into the molex connector. And Bam, you got it. It just already displays on the screen. And interesting. Just works, huh? Yeah, so you're just punching, you're basically punching in between where the game is with the with the screen screen? Yeah, yeah. And what's nice, also the x, the x and y axis, both have attenuators or potentiometers, basically, on the front end, so you can sort of fine tune it, if, if you have a really hot signal, you could you could, you know, dump it down a little bit. So, it, that's what I mean, when I was saying it's pretty much as easy to send an oscilloscope, yeah, you have to pop the back off. But all you really have to do is just punch wires into a Molex connector that already exists. And it just works. And so
Host 2 16:14
Instead of pumping your stuff through an attenuator already, well, yeah,
Host 3 16:17
Or designing some other thing that like, you know, punches it in, in parallel, you know, doing it this way you you do, you know, you won't get access to the game anymore, that's inside. But that's kind of not the point. Although one of the things that I was thinking that would be really cool, is to do a parallel style connection where you can mix in your audio, but you're mixing your audio into where the video is. So the video will like jiggle as you play the game, which would be kind of cool. So the two connectors I'm talking about, it's like I said, it's on page 32 of the schematic they are J 402 and J 506. Which is on the left side of the schematic, all you do is you pop them off of the basically the digital board and it's you know three signals and three grounds. So just plug your signals in there and modular synthesizer signals or 10 volts peak to peak basically. So you can just throw at 10 volt peak to peak signal in there, whatever it is, and you can modulate the
Host 2 17:20
Screen. He should totally pumped the audio into it. So he gets that that Lo Fi sound from that speaker system.
Host 3 17:25
That little crappy. Yeah. And you see the driver chip for the speaker. It's a gold classic lm 386 386.
Host 2 17:32
Yeah. That's like I've heard that before. Oh, yeah, Archie, I think I've built that exact circuit actually, before.
Host 3 17:40
I bet you this is just a datasheet rip. A bet you it's just like you take it and dump it right on there. And it works. Wait, wait,
Host 2 17:48
What are they using a five pipe timer for?
Host 3 17:50
Oh, look at it. You tell me what they're using it for?
Host 2 17:52
Oh my God, that's a outputs going into a transformer.
Host 3 17:58
And then that goes off to a driver transistor, which goes off to another transformer. Yeah. So it's boosting. Take a guess what they're using that for? Oh, man. See, I
Host 2 18:08
Don't know a lot about this kind of stuff. Or about 555 timers? Like I don't know what can
Host 3 18:13
Well, yeah. Okay. So see up at the top that that dashed? Rectangle? That's t 502. Yeah, that's the big high voltage transformers. So they're using that 555 as a switch mode controller. Gotcha. Yeah. So it basically they you know, it's it's that's big flyback transformer that hits the I don't know how many volts that CRT runs off of. But there's, there's two of the grids look like they run off 170 volts. And then there's a third grid that runs somewhere in the plus 50 volt. But I bet you that CRT is, you know, way higher than that. And you can see, there's kind of like a I don't know there's a diode off of the the big winding
Host 2 18:51
Yeah, at the very top it says says to CRT, I bet you that some
Host 3 18:55
You don't want to touch that wire, kind of the whole reason why I kind of like sparked up with that 555 thing was, I've been looking at some 555 switch mode supplies recently. And then I pulled up this schematic I was like, ah, that's great. Someone has done that. So apparently using a 555 Is it it works because basically what happens is you just set up the five five such that when your voltage drops, the 555 turns on, and it just basically hammers the transformer until it until your voltage raises again in the chatroom 555 off. So it's a really it's kind of like a self regulating, it's self regulating, but it's also kind of dumb, it won't know if something bad happens and it'll just keep trying until you know, either something works or something blows up kind of thing. Yeah. So it's it's not a really elegant way of doing it and it's not really efficient, but it's easy to do. If
Host 2 19:53
Little Jimmy touches the coil, it won't know.
Host 3 19:57
Ya know, it'll just keep bumping into Jimmy
Host 2 20:01
Well, yeah, if you look at some of these capacitors that are in this CRT area, you know, you got some one kilovolt ceramics over here.
Host 3 20:09
Mm hmm. Yep.
Host 2 20:10
I bet you that CRTs actually probably, you know, 15 kilovolts is up like that,
Host 3 20:17
Again, I wouldn't know I've in the, in a past life, I worked as a CRT repair guy. And most of the CRTs little screens we were using were in the tune of 5000 volt range, something like that. So I would think
Host 2 20:33
It would be that's probably around there, then up up there.
Host 3 20:35
Again, who knows exactly what it is off the top of my head, there's probably there's probably some listener who knows exactly what voltage CRT and runoff, so please let us know. Yeah, if
Host 2 20:45
If you do, I think it probably just depends on how big it is.
Host 1 20:49
Yeah, yeah. I know. The we used to repair gosh, the 22 inch CRT monitors, which those things were unbelievably huge and heavy. And those things ran off of a huge voltage. I don't remember what it was, but it was scary kind of stuff. Oh, that's
Host 2 21:05
Cool. I liked it. I like the 545 timer circuit. And the and the LM 386. That's that's pretty special there. Oh, yeah. Oh, let's see what else is in here. Oh, there's a 7905.
Host 3 21:15
Yeah. So a handful of J fits in there. Lm 340 A whole bunch of a whole bunch of NPN transistors, maybe not a whole bunch but a good spattering.
Host 2 21:26
What's interesting is that they're running the LM 340 as a five volt. Yeah. as well. Who why are they? Why are they using 277 90507905? That's a negative five volts. Yeah. Ah, that's what it's doing. Okay.
Host 3 21:43
Yeah, that's that looks like a pretty stock power supply configuration thing for a plus minus rail.
Host 2 21:51
Yeah, it's got some it's got some zingers in there for ESD. And stuff like that. It's pretty Yeah, it's pretty. Standard robots. They got a lot of diodes there too. For Input protection. Yep. Man got a ginormous like, they call it t 102. It's like a giant choke almost.
Host 3 22:10
But it's a triple choke, isn't it? Yeah. Yeah. Yeah. Right at right at the input coming off the transformer. Well, yeah, right at the input of the power supply after the mains transformer. When did the when did this thing come out? The vetrix. Let me see here. It's 82 in North America as let's say early 80s, early 80s, and 83. and Europe and Japan. And then it was just continued in 84. Yeah, it wasn't long lived. No, no, no, it's got a cool controller though, because the controller, like fits into the case. And it's got four buttons and a joystick. And it's one of those ones like it's, it looks like I guess it's a hindsight 2020 kind of thing. But the controller is just absolutely awful to when you put it in your hand. And it was, this was at a time before when like, you know, controller ergonomics didn't, or people weren't paying attention to that, or I shouldn't say not paying attention to like we talked about
Host 2 23:09
This last episode is it's like an NS controller step with a joystick and an extra button.
Host 3 23:15
Well, it's got Okay, so it has four buttons in a in a line, like
Host 2 23:19
A four buttons that no I've had, yeah, four has four buttons. Look at the human thumb.
Host 3 23:22
It doesn't like a straight line.
Host 2 23:27
You know how they changed how they did colors on the vetrix.
Host 3 23:30
But didn't they just have three beams? No. Oh, no. They put the overlays over the screen, right? Yeah,
Host 2 23:37
They had overlays. So when you played like Space Invaders, there'd be a red, green. And then I think the scores are white. So is clear. So you just slide the Space Invader overlay, and your colors.
Host 1 23:48
Yeah, it wasn't there. Like I thought there was a version of there was like a submarine hunting game, where you put like this big like heads up display on your screen. And I had like all this data and stuff in there. It actually looked really cool. Oh, man,
Host 2 24:04
What was that? Like wolf hunter or something like that? I don't remember what the sub Hunter one was called by doober playing it
Host 3 24:11
And there was there was the Star Wars vector game where you went through the the trench right? Yes, then but that was like arcade. Yeah, these are all arcades only only an arcade. Cool. Well, whenever whenever we get this modded up, I will have to take a video and show that because we actually we actually have some pictures on the door to the Office of someone who has done this before. Some vector images that are audio displayed in vector and it looks really cool. I do
Host 2 24:39
Like how the last page of the service manual is like how do you box this thing up? Really a drawing of how the box and where to put the serial number and Oh, no lie. Look at that. You know, you don't see that anymore. And that's hand drawn to look at that. Yeah, that's cool. That is cool. Yeah, don't really recognize any other icees in this thing. Everything else is kind of custom.
Host 3 25:03
There's some analog switches 4066 Let's see what else we got.
Host 2 25:09
I was looking at like the CPU and stuff.
Host 3 25:12
Oh, yeah, all that stuff. Yeah, I bet you was it was all custom
Host 2 25:16
Answers rom MPU six, eight a oh nine. I don't recognize that. 6522 looks interesting was a which I see is that I see 207 I wonder if that's a space of a 66500 series MCU
Host 3 25:34
Ah, it has a read white Read Write pin on it. Pin 22 So I'm wondering if it can that Read Write pin connects directly to the cartridge receptacle? Oh, I didn't know that. I thought the I thought these things were single game. They have a whole like game cartridge slot.
Host 2 25:56
Yeah. Yeah. Game carts.
Host 3 25:57
Host 2 26:00
All right. Yeah. So that's that, go check out the service manual. Pretty cool. Yeah, Paul posted what you've been up to Parker. So I haven't been able to do much. You were talking about like getting your own space together. Since you're, you know, apartment hopping. And I'm finally getting like my electronics section here at home set up now. Basically making space in the garage for hopefully in about a month. have that all done. I'm like cleaning cabinets and stuff right now. Really fun. Yeah, boring things. But I didn't manage to work a little bit more on that software defined radio, I managed to get a Python script running on the Raspberry Pi that talk to an Arduino. And so when I moved like a pin jumper on the Arduino, I could detect that on the Python side that's running on the Raspberry Pi. So that's like the basis of like how it's going to work now. Nice. So I have an embedded system, pulling the you know, the input outputs and sending it over to the Python. And next step is to get the Python to control the signal to find radio, and then basically make a simple tuner is a little overkill for what it's going to be doing at first, but eventually it will be a pretty good radio, I think,
Host 3 27:22
Nice. Are you going to have that code available? Because I would totally like to look at that.
Host 2 27:27
Yeah, when I haven't more cleaned up. I was just kind of like throwing stuff together.
Host 3 27:33
But it works. Right? It does
Host 2 27:35
Work. So once I get a mic once I get it, like talk to the SDR talking to the Python with like, some like you do something Arduino. And the Python actually does something besides like register that you press the button, then yeah, I'll post that stuff. Cool. So I should have that done by next week. So that'd be really, yeah, that'd be pretty good update for it. To do that. And then I'll start actually designing a circuit board and stuff. You know, the fun stuff.
Host 3 28:05
That's the point you want to get to.
Host 2 28:07
Yeah, stuff I really want to get to is like, I actually really enjoy doing the mechanical design stuff. Especially for stuff like this, which is like, I'm going to be designing a retro looking radio, I guess not technically not mean that retro. It's like 80s era, instead of like 50s or 60s era.
Host 3 28:26
Have you decided what is going to look like? I mean, in terms of like, do you like have a napkin drawing kind of thing?
Host 2 28:33
I think just the big, you know, VFD display, and then two knobs on the side. Yeah. And get knobs that are? It's an eight way directional knob with an encoder and a push button. Yep. And that's it.
Host 3 28:47
Yeah, make it make it pretty stripped down and clean. Yeah, it will look,
Host 2 28:51
I put some buttons underneath it for like, because that's how old radios look. They had those buttons, at least a car radios they had the buttons underneath. The trick is going to be having. Usually those are gained together. So you press one and then when you press the other one, that first one pops back out. There's
Host 3 29:06
A name for that. I don't. I don't remember what that's called. But I know exactly what but you're talking like old multimeters had that on the side?
Host 2 29:13
Yeah, I don't know how to make that. So I don't I might just have to be like momentary style switches that you press. Yeah. It would be nice to figure out how to make that work or buy a module that does that already. That's about what needs to be like six inches wide. So
Host 3 29:31
Yeah. Are you gonna 3d print like the shroud that goes around everything?
Host 2 29:37
I think I'm going to take up your suggestion and make it out of wood. Okay, cool. Yeah, it's actually you know, cut it on the scroll saw and sand it and make it all look nice. I just got to find some really tight grain so it looks like fake wood.
Host 3 29:52
Yeah, you know, Maple might be good for something like that. Oh, yeah. Do you want to do a Do you want to do it dark? Are you gonna like stain it
Host 2 30:00
Or it's probably gonna be darkish sunless stain it
Host 3 30:03
Maple take stain that will the kind of maple that I'm talking about. It takes it okay at best if he asked me.
Host 2 30:11
Yeah, my best working with Maple is you don't use a stain use a dye. Yeah, yeah, exactly. That's how we did. That's how I did your your first synthesizer. Oh yeah. That was me I curly maple and it would not it would not take a stain at all. And so I got some dye and I just dyed the hell out of it. Right. Yeah. And that that worked great. I actually still finding like clothes that I've gotten that dial.
Host 3 30:40
It was kind of like a deep red mahogany ish color. So
Host 2 30:43
Use that thing. Oh, no, it's it's been retired to the wastelands. It's,
Host 3 30:49
Um, it will go up in my workshop as kind of like a relic. But like a,
Host 2 30:56
Like, a relic of a bygone era. Yeah, yeah, I remember it. Man. I remember you how long it took you to build that board that goes in there. She built it all by hand. A surface mount but with like a regular iron?
Host 3 31:09
Oh, yeah. No, it's 650 Plus parts, something like that. Yeah. And yeah, no, I didn't. I didn't paste it. I did it all by hand. Yeah. I sometimes I like to torture myself. It's kind of fun. No, I really like soldering. Just, it's fun. I just enjoy the journey, you know, towards the end result. And so like, it's fun to have like a big, nice, fancy, super expensive machine, build your stuff. But it's also kind of nice to just be like, I don't know, I'm getting goofy here. But intimate with your like your project. It's you did it, you know? But everyone's different. Yep. Cool. You want to roll on over to the RFO?
Host 2 31:55
Yeah, we can roll on our FFO. Awesome.
Host 3 31:58
So this is this is a question that you wanted to ask? Well, and this actually came up a little bit today. I was working a little bit with the simulation software. Mainly it was P spice, which we've talked about this before. But I kind of wanted to bring up a question. Really, this is for mainly all of our listeners, but also for you, Parker. Simulation. Do you use it? Do you ever simulate like, is it in your like wheelhouse? Do you know how to do it?
Host 2 32:28
So yeah, I think I've answered this one before, but I 90% of time, I do not use simulation, because I'm doing digital digital design. And I know when you start doing really high speed stuff, simulation is very important. But for doing microcontrollers, and better design IoT stuff, it's not really necessary. As long as you make sure you know, you make sure your traces are short you making sure your your impedance is low, your your parasitic capacitance is low for your signals. Beyond that, you know, also making sure like your levels are fine. So when you start mixing chip families, you're like, Okay, making sure a logic high is actually high enough for this one other chip, you know, stuff like that, like it's sometimes 2.5 volts is not enough to flip a 3.3 volt logic. Right, right. And that's stuff that it'd be kind of hard to simulate, unless you've really told it what it was, what the chips
Host 3 33:29
Were, well, and a lot of times chips of that sort or ICs are not available in simulation software. They're not something that either can be simulated, or no one's created something for that. And I
Host 2 33:42
Would suspect, though, there is probably a, like, let's say, an Arduino simulator, where you can like, upload your code, and it would run.
Host 3 33:52
Well, I think there's multiple of those.
Host 2 33:55
Yeah, I would say that would exist, but for most like see stuff, like let's say an AFMA. There's no simulator for that.
Host 3 34:04
Well, okay, so if you were to do simulation, do you have a piece of software that you would use?
Host 2 34:11
I use? P spice or LT spice, okay. And that's mainly for power supply stuff. I will try to like say, if I'm designing a power supply, and I, you know, the regulator I'm using has, has whatever. It's, it's in the software like P spice or LT spice or whatever, it has a model basically. Yeah, I will. I will simulate like the filters and stuff to make sure I'm getting out the noise I want to get out. And that was actually kind of the idea behind the super simple power supply was it could record noise, and then play it and then play it back. And so what the one the one I'm more interested in is like automotive noise on the powerlines. Like, how noisy is that stuff? Does your filters on your power supplies sufficiently squelch that out?
Host 3 35:06
Right. And and you've, if I remember, right, it was, was your Octo prober project where you put like a crazy pipe filter on the front end? Or was it that did the Jeep board does the Jeep
Host 2 35:20
Prop? Yeah, there was, that thing was super over built on the power supply, I think you can probably run like two volt peak peak into it, and it would just completely kill it.
Host 3 35:29
Yeah, they had a pretty crazy filter on it. So. So I personally, I use p space 9.1, which is like the Student Edition. And it came out a long, long time ago, it was what I used in college, so I'm most used to it. And I really enjoy that one. And I'm fast at it. That's why I go for it. However, it's very old, it has a lot of problems running on Windows 10, you kind of have to do a lot of workarounds just to be able to use it. And it crashes on occasion. So it's just old, but I really I like it. And I also use LT spice because that is more modern in terms of it's supported on Windows 10. But I'm what I'm curious about is do any of our listeners do simulation? And if you do, what do you use? And what do you prefer? On that? I'd love to hear that. And and really the whole like it like Parker said, we have talked about this before. But now I'm extending this question from Parker to everyone else. I'm really curious to hear what everyone uses. Or if you know, I'd also love to hear like, basically what percentage of people even care about simulation? Is that something that they want to do so not to sell the Slack channel again, but jump on our Slack channel. And, you know, either go on to the general channel or you know, send me a personal message. I'd love to hear what you guys do with simulation. And you know what your success is?
Host 2 37:01
And actually, if the if we should be doing more simulation, before we start designing stuff. Yeah, yeah. You know, is there a good argument for that? In my opinion, for IoT embedded system stuff, it's probably not necessarily a waste of time. It's difficult. It's difficult, but it's like, it's also it's, it could save you time, as well, though, man, that'd be awesome. If you could design your board, or design your circuit, simulate the circuit to make sure everything's working like, Yeah, I'm talking about digital here, working signal wise. So like, everything's working, you can make sure everything plays nice with like, all the ICS ESD diode stuff, you know, when that chip turns off, you know, are you gonna be back feeding voltage into it, like simulating all that would be really cool. You lay out your board. And then you give it some code, and it could somehow figure out the emf of your device as well. And so you can really start tuning for, you know, FCC CE.
Host 3 38:07
That sounds I mean, that would be amazing. But that sounds like a very, very expensive plug into whatever package you're using. Yeah, why don't you read an eagle you up? ELP that does all that it does that? Yeah. It analyzes your gerber files and like, actually runs that. That'd be kind of cool, actually. Yeah, so So actually, one of the things I was doing with it today, we had a circuit that we wanted to make sure that when you turn a potentially ometer on this circuit, it, the output was you were able to control from negative 12 db to positive 12 DB. Basically, it's a gain control in a way, in a sense. And it's a it's a it was a generally it was a fairly simple circuit, it was like a dual transistor kind of amplifier control system thing. You know, just being able to mess around with resistor values to make sure that the, the taper of the potential ometer played nice, and that we were actually hitting plus minus 12 DB for the whole range of the potentiometer. It's kind of nice to just be able to do you know, an hour and a half of simulation, and not have to, you know, actually build it and then figure out why it doesn't work. At the same time, you know, we'll build this board. And it may not work exactly the way the simulation does, that's just kind of the nature of the beast. But in my opinion, that's the simulation gets you, you know, 90% of the way there and then you finish the last 10% with real world values and things like that. But at the same time, something that was really nice is being able to, you know, just modify a capacitor somewhere in the circuit and see the impact of that capacitor. Because there's a lot of times when you're designing things, and I think that this this kind of topic can be confusing for new guys. But there's a lot of times where you just put capacitors down because you know, one needs to be there. But now Not necessarily what value it needs to be like in a feedback, semi simulation, you know, modifying capacitor values and seeing what it does to your frequency response can tell you a lot without having to go to actual physical calculations. And I love using schematics for that aren't sorry, simulations, not schematics. I think that's a really useful tool there.
Host 2 40:22
Well, you're drawing a schematic and make the simulation happen.
Host 3 40:25
Right, right, right. But I guess what I'm saying is like, I know a capacitor needs to be somewhere, modify its value, see what it does? Pick something that works. Gotcha. So a lot of times, it's easier than writing out a transfer function. is practically always easier. You remember having to do those back in college? Those are fun. I love a long time ago. Yeah, Laplace transforms till you go blue in the face.
Host 2 40:52
Yeah. So the next topic is going to be you config. It is a key CAD schematic symbols for PDF generator, or, yeah, from PDF, from PDF. So I actually tried this out earlier today, it basically parses PDFs, I think it's probably using object, you know, it's actually looking at in parsing the letters out out of the PDF. And then using his call, he calls automagic. It finds diagrams, and basically makes a pin listing for you. Interesting. So like pin one, is this pin two, is this pin three is this.
Host 3 41:36
Oh, okay. I see. Now he actually has an image up on his GitHub, where he's actually extracting something from a datasheet. Correct. So that's what it does.
Host 2 41:45
Oh, that is cool. And I did some testing with this. And it actually seems to work pretty good. The thing about data sheets is they're always or mostly they're always black and white. There's sometimes some color logos and stuff. But a drawing in a PDF is going to be typically black and white. If you listeners know of a PDF that's not like that, let me know. And we'll should we should run it through it and see if we can grab it, huh, yeah. So it's not 100% Perfect, but it actually works. This tool you can fig actually works pretty well. It's pretty cool.
Host 3 42:23
I think I think I might actually have a datasheet for a display an OLED display that is in color, I'll have to check on that. And get back to you on that. But I got one the other day, because I was just checking dimensions on on an OLED. And I know at least some of the pages have color on them.
Host 2 42:43
There was another one that is like a really cool bill of material, like Gerber viewer. So as you like hover over like you build materials, it highlights where they where it's at on the board. So it's very good. If you're doing hand placing parts, you can basically upload, open up your that program and say, Okay, I want to play see one and hover over it. And it'll show you where it's at. Yeah, it was like walking
Host 3 43:10
You through building your own board, which yes, is awesome. So
Host 2 43:14
There's been a couple cool tools like that coming out. I'm hoping to put this you config through a little bit more little more tests. And the cool thing is open source so you can gleam into the automagic
Host 3 43:28
I so i have not worked at macro fab in a while. But I can I can kind of smell that this you config thing is sort of like macro fabby. It sounds like that sounds like something that macro fab would love to have their hands.
Host 2 43:44
And so what I've been able to look I've been looking through like its documentation stuff. And so what it kind of does is it look it's looking for, so it parses the horse datasheet right. And then it's looking for basically, I table of numbers and descriptions is what it's looking for really. It's really smart how it's going about it
Host 3 44:10
Does it when it creates, okay, I think I'm answering my question here, which this this is totally cool. When it creates a schematic image or a symbol it it will automatically arrange all the pins in numerical order correct even if the datasheet isn't necessarily like that.
Host 2 44:30
Correct. That's it does do that. Yeah. And you can pick like different shapes that's going to make the symbol out of which is cool. What I'm hoping for next that this guy comes out with or someone else is one of those footprints. If if a if KY CAD can do the symbols in a a footprint from a PDF, I will probably switch over and suffer but making the hearts would be so much faster.
Host 3 45:02
Okay, so this, this really sucks. But you broke up right at that point. Did you just say that you would switch from Eagle to KiCad?
Host 2 45:10
If it could do the layout? Wow, that's
Host 3 45:13
That's a big statement. So
Host 2 45:15
They could do if you can do the footprints, then yeah. Because it actually seems to do that symbols quite well. This this program this guy's that this you config? Yeah. Because really that's like my biggest, like hang up when designing a board, I will always try to go through my library and find something might be sub optimal. Just to avoid building parts. It's not because I'm slow at building parts or eagles. Actually, I like building parts in Eagle. It's just, I don't want to do that. I want to plop some parts down drive drawls nets up and get the layout as fast as possible. Hmm, yeah.
Host 3 45:56
Interesting. I think building parts is part of the journey. So I just, I don't try to avoid it. I just think that like, it's just gonna happen.
Host 2 46:07
Is it the, the destination is not what matters is the journey, right? It's the building the
Host 3 46:13
Footprints that matters? building footprints.
Host 2 46:17
Yeah, but the journey doesn't matter if the payoff doesn't work either.
Host 3 46:20
Well, that's true. Yeah. And so
Host 2 46:24
The next RFO is samsam caps, counterfeit parts rampant question mark. It's kind of a click Beatty item here. But so last week, we were talking about some parts that Steven ran into that were counterfeit, Samsung capacitors, right. And some people in the Slack channel have also ran into counterfeit Samsung capacitors.
Host 3 46:48
Yeah, kind of. It was surprising because talking about that, that subject, it sparked a lot of other people saying, hey, there's, there's issues that they ran into. And makes kind of feels a little bit vindicating. It doesn't it makes it doesn't seem like, you know, we made a mistake or anything like that sounds more like this was out of our hands kind of stuff. Which is interesting that there's other people who've been having this issue. But one good point that somebody made, I apologize. I don't remember exactly who it was. But you know, Samsung being a big brand, like, they're just, you know, they're they're ripe for being counterfeit head, you know? Yeah, cuz
Host 2 47:26
Because Samsung is a new or in quotes player in the chip part game, like capacitors and resistors. I don't know if they make resistors yet, but I don't think you make capacitors. And the the thing about them is what I think what makes the counterfeiting them ideal to be counterfeited. Is there an established brand Samsung, right. Yeah. And they're new to this market. And what they're trying to do right now is the is the basic undercutting all the other manufacturers out there in terms of price. And so they already had the lowest price. And so when the counterfeiters come in, they are counterfeiters are always usually cheaper than the real thing. And so they come out slightly under price from Samsung. So you're already like, Okay, we know Samsung parts are cheap. The brand looks good. And these counterfeit parts are probably legit, right? Yeah. Because it looks it's it passes the sniff test. Whereas if it was if they were faking a merata part, which are generally more expensive capacitors, and they came out well under what the normal market value is for merata part, you might be like, something's a little sketchy there.
Host 3 48:52
Sure, it makes sense. It's interesting. Yeah. If you've, if you've experienced any heartache with some Samsung capacitors, please let us know. I'd love to see if this is a bigger issue that a lot of people are seeing. I
Host 2 49:06
Think that's going to wrap up this episode. Steven. We're at like 15 minutes.
Host 3 49:11
Yeah, this is a counterfeit episode. Actually, this is not Parker and Steven talking but
Host 2 49:17
This is Steven and Parker.
Host 3 49:19
Yes. So well with that, that was the macro fab engineering podcast. We were your host, Parker Gilman. And Steven Craig. Later everyone died. Can't take it easy.
Host 2 49:41
That's right. That's right. It is what it is.
Host 3 49:43
Yeah, there we go. Yeah.
Host 2 49:53
Thank you. Yes, you are a listener for downloading our show. If you have a cool idea project, counterfeit parts, topics. or simulations that you like to use. Let us know at macro fab or at analog EMG or at Longhorn engineer with no O's, or email us at email@example.com Man we are, we can get available anywhere or slack. We can do slack too. 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 wherever you listen helps the show stay visible and helps new listeners find us now haven't checked on our reviews and well because see if they're so good
Transcribed by https://otter.ai