We would like to thank everyone that entered into the MacroFab Design Contest: Blink an LED Sponsored by Mouser Electronics. The winner for the Pragmatic Blinky was Dillon with the Disintegrated LM3909 – 1.5V LED Flasher. The winner for the Most Complicated Blink was Paul Gallagher with The Bouncy Thief LED Blinking Machine. And The winner for the Wearable blink was Gerben with the Led eyelashes.
- MacroFab Engineering Podcast Favorite discussion
- TPS4021 4.5-V to 52-V Input Current Mode Boost Controller
- PMP8621 TI app note for doing an 18V to 300V@ 10mA supply
- Datasheet issues
- Two dimension drawings?
- The thermal pad – What do you connect it to?
- TPA3116 – 30W from an 18V supply
- TPS4021 4.5-V to 52-V Input Current Mode Boost Controller
- RE: Simulation talk from last week
- David Patterson emailed in and suggested HyperLynx Design Rule Checking (DRC)
- RE: Jeep Wagoneer Project
- Brian Gosney emailed in about his ’77 Dodge Colt Radio project
- Taking the stock AM radio, removed electronics and replaced them with Brian’s own design
- Bluetooth connectivity
- Fuel Injection: MegaSquirt?
- Brian Gosney emailed in about his ’77 Dodge Colt Radio project
- OpenMV Cam H7 – Machine Vision w/ MicroPython
- The OpenMV Cam H7 is an open-source MicroPython powered machine vision camera designed for low-power real-time applications
- More powerful than the previous version (2x)
- Removable camera modules: Global shutter and thermal sensor support
- Kwabena was on MEP EP#27: If There is a Bug, You Can Fix It
- RE: Simulation talk from last week
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 fed engineering podcast. We are your hosts Stephen Gregg and Parker Dolman. And this is episode 138.
Host 2 00:20
I would like to thank everyone that entered into the McWrap design contest blinking LED sponsored by Mouser electronics. The winner for the pragmatic Blinky was Dylan with the disintegrated lm 3909 1.5 volt led flasher. The winner for the most complicated blink was Paul. I hope I'm pronouncing this correctly, Gal Gallagher. Yeah, Gallagher, with the bouncy thief led Blinky machine. And the winner for the wearable blink was Gerben with the LED eyelashes, and check out the macro blog for more information on the winners. And I put a couple other links of like notable entries because they were really cool. And I think on this episode of the podcast, we are going to discuss the macro engineering podcast favorites.
Host 3 01:07
So we had what was it 27 entries, and everything was fantastic. All of them were really fun, all of them were really innovative. And there was a huge spread of different ideas for something as simple as blinking an LED. So thank you to everyone that that, you know, submitted their ideas. And, you know, congratulations to the three winners. So hopefully you'll have some some bucks coming your way soon. Right?
Host 2 01:31
And working on that right now.
Host 3 01:34
So what do you what do you what was your favorite Parker? Or how are we going to do this? How are we going to just I guess we'll walk through talk about some of our favorites, talk about how we're gonna do this because we're gonna we did discuss this beforehand. And we'll discuss as in like how we sort of come up separately with these ideas. So I kind of have my sort of favorites. And Parker's has his and we're just gonna kind of see how we overlap here, I guess. Right? Does that sound good to you, Parker?
Host 2 02:02
Yeah, that's how we're gonna do it. So I think we should do 111111. So let me start with mine first. Okay. One on my list was the map LED. That was the one that I'm gonna post the link here. That was the one where the he had two LEDs is plugged into 120 volt 60 hertz means.
Host 3 02:26
Yeah, his name is magic wolf phi or wolf
Host 2 02:30
Phi. Yeah, Wolfie, I think. And I really liked this because it was it's the simplest way to blinking LED. And it definitely if we had a Don't try this at home kids award, it would definitely win.
Host 3 02:45
Oh, yeah. Well, hey, I'm looking at the pictures right now. There's some heat shrink, I say some, and that it looks like some electrical tape a little bit.
Host 2 02:56
He's minimizing exposure to the danger.
Host 3 03:00
Yeah, minimizing in quotes. Now, that's a really a, we had mentioned this on a previous podcast, that's a really, it's just, it's goofy in its simplicity, but it totally works. And technically, they're blinking. They're blinking really fast. So
Host 2 03:16
Yeah, the only thing is, it's kind of not really useful, because you can't actually see it blinking unless you film it and slow it down.
Host 3 03:27
Right, right. Right, by doing like, actually, let's, let's back up real quick. And just for those who may, maybe this is one of their first time listening. So in this design contest, we're just blinking an LED. And that's it. That's it. Uh, we wish there was a few other rules that were within the boundaries and stuff. But you could enter into one of four categories. Correct the work, we're judging the last category right now, which is basically Parker and I think one is either funny or cool or interesting or unique or whatever. And we're gonna pick one here so, so that that's, that's what we're doing right now. Yeah. Okay. Yeah. So it's that I think that's a fantastic project. I did not actually put that on on my list, though. I think I think there were some others that I thought were a little bit more exciting than that.
Host 2 04:14
Yeah, that one definitely gets a honorable mention for me, because it's definitely unique and a interesting way to go about the solve the problem. I bet you if you were in a country that was running on 50 hertz, you could see it flicker huh. 60 hertz might be a little too fast though.
Host 3 04:34
But wait, hang on. It's only blinking each LED only blinks for half the cycle. So it would actually be half as fast right? Each LED because it's off for half of the cycle and on for now, maybe I'm wrong. Whatever. I don't know. I'm getting good. I'm confusing myself here. Forget
Host 2 04:55
All that. It's still blinking at 60 Hertz.
Host 3 04:57
You're right. It's still blinking. 60 hertz I was confused. Myself, I realized that halfway through that sentence, and I was like, wow, that's dumb.
Host 2 05:04
You're thinking about duty cycle. Yeah, I was thinking duty cycle.
Host 3 05:07
You're right. You're right. Okay, cool. Well, let's go on to my first pick on that. So I want to make sure that it was kind of like knowing that I didn't look at any of the other judges picks. So my picks may overlap with theirs. And this one does. The the first pick that I had was Paul Gallagher's bouncy thief LED.
Host 2 05:31
Now this project is really cool.
Host 3 05:34
It's super cool. It's super, super cool. So I had a lot of things that I kind of just, I looked through each and every project, and I wrote down some simple notes about the project that I thought like, Hey, this is cool. This part was great. And I wouldn't necessarily say that I'm judging them in a way. But I wrote down things that I thought were notable about each one. So here's a couple of things I noticed about the bouncy thief led, I thought it was a very, very interesting concept. For the whole blinking LED idea. The initial drawing was presented with the idea which I add bonuses to that, because I thought that was really great. Oh, the drawing is great. Yeah, the draw. Yeah, the drawings. Fantastic. So it's kind of cool that there was like, there was thought beforehand that was shown in this. I thought that was really cool. So the the concept of this, this project is really, really fun. And it opens up a lot of questions like, oh, my god, is that really doing what that's doing? Why is that doing that? How is it doing that? You know, so there was a whole lot of that going in my head. I thought he had really great pictures and videos on his hackaday.io page to kind of support that. And the last thing I wrote down about it is I think it's funny as hell, just because like, it's so goofy, and I guess let's I'll do a quick little description, I suppose. It's it's like a stack of magnets with a with a double A battery, or sorry, a triple A battery on it. And surrounding everything is a is a coil that he wound up with some electronics on top. And this coil just, it completes a circuit, but it like oscillates, and it freaks out and bounces all over the place. Well, blinking an LED. And that's that's a just, it's a difficult way to describe or a difficult project to describe. You'll have to go and check it out. But I thought it was just really, really cool.
Host 2 07:24
Yeah, it was definitely one of my favorites. Yeah. But it was not one of the ones I picked. Ah, okay.
Host 3 07:29
Okay. So what, what is your second pick?
Host 2 07:33
So the next one I picked was the Arduino birthday candle by Mr. Matthew. Ah, yeah. And I picked this one because it definitely was a interesting take on the whole idea of a blinking LED. Basically, he is using a microphone to detect wind noise. Are you breathing on it? And then the LED goes out. Right? So you could blow out the LED? Yes. And I really like because it is a very practical reason to have a blinking LED on a project. Oh, that's
Host 3 08:06
A good way of putting it. Yeah, yep. And he has a bunch of good, good descriptions and images on his page. Yep.
Host 2 08:14
And he basically builds all the way through the prototype and tests and it works. So I thought it was a really good project. And I kind of like just, it was something I never really thought about before. As a concept, and I kind of liked that.
Host 3 08:31
Yeah, that's, that's fantastic. All right. So for the second project that I picked, this one probably won't come as a surprise. But I chose the guitar expression pedal indicator. I knew you'd pick that one. Basically the same, the same reasons that you basically just said, like, this guy actually solved a legit issue with blinking LEDs in this sense. So in many situations, in guitar effects world, you can have a little foot pedal, where the foot pedal, you literally put your foot on it, and you tilt it to adjust some values in some software or program or whatever you have going on. And most of the time, you don't have a visual cue of what's actually happening with that foot pedal. Mainly, it's just based off of, you know, you feel your foot what angle your foots at, well, this, this guy built a it's a small daughterboard. It's actually a pair of boards that mount together and fit inside of this enclosure, this foot pedal enclosure, and it gives a readout of basically the angle of the foot pedal, which I think is super great. The the idea that he's kind of solving an issue, that that might be a little bit difficult to know, especially if your foots not on it, you know, what position is it at and things but some of the things that I really liked about this project was, first of all, it's really practical. Second of all, he has he worked out a lot Industrial Design, he took someone else's design and he worked out something that works with that other design. So it's not like he was going from scratch. He had design parameters to work around and did that. It's a great two board design. There's actual connectors, he use cables to connect everything together. I thought that was fantastic, is a really good write up and the documentation is great with good images. And of course, he won my heart because his board was designed to did trace.
Host 2 10:33
He gets bonus points for me because this board is read.
Host 3 10:36
It looks like a macro macro board, that's for sure. Yeah, I
Host 2 10:39
Don't think it is, though.
Host 3 10:40
It looks like it's hand soldered,
Host 2 10:42
It looks like but the I do like the, with this project. I do like how you're right. He kind of worked around a design of this, this panel, and added his own feature set to it, which is really cool.
Host 3 11:01
And if you look at the images, it looks like it fits. It looks like it belongs there. You know, it doesn't look like it's hacked in. Correct. That's a really cool project. And that was by a guy named sort of engineer.
Host 2 11:15
Well, he's a he's an engineer in my book now.
Host 3 11:21
So Parker, what was your third pick?
Host 2 11:24
My third pick? Was the solar powered flashing LED heart pendant PCB coil by Bob ridiculous, Bob. I think that's how you say that.
Host 3 11:36
Bob vicious, I
Host 2 11:37
Think Bob Mauritius? Yeah, I really liked this because the the project is really well laid out. I do like I like the idea of using a coil in the PCB as a as the transformer, or inductor. And I just thought that was really unique. And I kind of like how the board is just designed, like the traces look really cool. And the art on it looks really awesome.
Host 3 12:05
Yeah, I think he did a fantastic job.
Host 2 12:08
And it's not a and how it works is it It charges up. So it uses a jewel thief to pull in the power from the solar panels. And it charges up a capacitor and then the capacitor, once it hits a certain spot, it turns on the LED and which drains the power, and then turns off the LED and then it starts over again. Which I really liked that kind of self. You know, it's like a self regulating oscillating circuit.
Host 3 12:35
Yeah, and even has some really unique silkscreen on the on one side of the board. So I would, I would have to say that I believe that we have found ourselves a winner, because I also chose that project as my third pick. Oh, there it is, I thought that this project was really, really unique, it's super cool to see somebody take something like the PCB transformer, and build something that's, you know, somewhat useful, but fits within our parameters with that. So I love how the PCB was part of the project itself being its own component. And on top of that, he took that concept and fit that really kind of like rectilinear square transformer, and put it on a board that shaped like a heart where he was able to, you know, kind of make that all fit. So there's there's a little bit of the aesthetic side that goes along with the cold hard, like, it's got to work kind of thing. I was really, really impressed with that. And some of the things I wrote down about if it's really innovative and unique. It was it was really cool, where he put the the transformer on the board. And he also had really good documentation, which I always give a plus to that. So I think we have a winner. And that goes to Bob nutricious.
Host 2 13:52
Hey, Bob versus will I'll send you an email, you know, tomorrow with some instructions
Host 3 13:58
Now. Congratulations. And once again, thanks to everyone for entering in that was a ton of fun. I hope that every one of you had fun, even if you didn't enter in, you know, going and checking the the projects in here and us kind of yap about them every week. I certainly had a ton of fun with it. And I hope we do more stuff like this in the future.
Host 2 14:19
Yeah, I hope we I'm aiming for next spring. Cool. Very good. It's just amazing the support our community gave to to us for this project for this contest. And it's just it was just a ton of fun and all the judges had fun. And, you know, it just was a good time for everyone.
Host 3 14:39
Yeah, I guess we should also give a shout out to the other judges who helped out with that. I know Alicia white from the embedded FM podcast was one of them. So thank you very much, Alicia.
Host 2 14:52
And then James Lewis of the bald engineer blog, Catherine Scott, who is a computer vision robotics guru and Derek Broder of the current source.
Host 3 15:02
Thank you so much for, for joining us in the fun.
Host 2 15:06
I'm just looking at all the other winners that they picked. Were there some runner ups? Yeah, I put the runner ups as the notable entries and stuff.
Host 3 15:16
Is that up on the blog, the macro fab blog? Yes. Okay, cool. I might have to go check that out myself. Mainly because I wanted to keep this as I guess you could say clean as possible. I kind of avoided reading all that other stuff, because I wanted to have my like, my own thoughts on the projects.
Host 2 15:33
Yeah, I picked them over. I picked them by last Friday, before I even looked at all the judge stuff.
Host 3 15:39
So it was untainted? Yes. So to speak.
Host 2 15:44
So Stephen, before you go check out the blog. What have you been working on?
Host 3 15:49
Well, okay, so I've got a kind of a unique project, something that cropped up recently. And this one is sort of a map project and sort of not map as in, like, I'll talk about it. And I hope to put this up on my new blog, analog inch.com. The, there's a guy at work, who's also a tube head, and I've kind of been, you know, chatting and hanging out with him. And we both came up with this idea that we kind of wanted to build an app together and sort of design an app together. He's been doing electronics for a while, but hasn't really gotten too super deep into it. And he attended my class the other day that I taught on just learning dip trace and things. And he was like, Let's go further with this. I was like, why don't we design an amp? But why don't we make it fun, as opposed to just like doing a well copying something? Yeah, well, I mean, doing an old tube amp is fun. But why don't we make it interesting. Let's put it that way. So we're trying to see if we can get a tube amp into a guitar pedal enclosure. Oh, that's cool. We're trying to get a 30 watt to preamp with a solid state power amp, and switch mode power supplies for all the power. Basically, we want to make a whole tube amp where you plug an 18 volt plug back into it, you get the 350 ish volts in the preamp, you get the 18 volts for the output, you get 12.6 for the heaters, and then all the other little stuff you need in between there. So we're kind of like coming up with ideas for that.
Host 2 17:17
So is the tube going to be inside of it or poking out,
Host 3 17:21
We are still deciding how we want to do that we haven't really done much of the industrial style design yet. But one of the things we discussed is putting the tubes horizontal and milling out windows in the top of the enclosure and putting you know some mesh, some steel mesh, so you could see the tubes from inside the enclosure. And we can get goofy and put LEDs and make them glow and things like that. But the blue LEDs in there. Yeah, that would be that'd be super cool. Well, and what we were thinking, you know, a little bit along the lines of maybe kill two birds with one stone, because those windows can be kind of vent windows for heat, because we do have a 30 watt Class D amplifier inside. And we're gonna have switch mode power supplies that are doing some pretty hefty work. And so we got to get heat out of it. But it's not, it's not something I want to put a fan on or anything like that. So the pedal is probably going to run pretty hot. But we'll see. But one of the things I have already begun doing is picking the switch mode, power supplies, and the power amp. The A lot of the other stuff we're going to do in terms of like the preamp and the tone shaping, we're going to breadboard that and then build it into the circuit. But those other things are just known, like, I know I need a power supply that will do whatever. And and what was funny is I wanted to use a boost power supply for this well, you pretty much have to use a boost power supply. And I wanted to stay away from a flyback style switch mode power supply mainly because I don't want to a wind my own transformer or be going to get someone else to wind a transformer for. And there's not a lot of options for buying an off the shelf flyback transformer. So I just didn't want to go through the headache of doing that. And if you look at the calculations for a standard boost converter, trying to go from 18 volts to 300 plus volts, you'll have the duty cycle of your on time, like 98%. And so like it doesn't really work very well. I mean, technically, there are chips that will do that. And technically it can work. But the amount of time you're giving your switch your MOSFET to turn on and off is really, really tiny. And so you have to have you have to have a really well picked switch and all because I didn't want to deal with that headache. And I was digging around Google and surprisingly I found an app note from TI which the app note is PMP 8621 and it will
Host 1 20:01
Absolutely crazy because the title of this app note is doing a 18 volt to 300 volt at 10 milliamp switch mode power supply as a boost converter. And so I'm just like, oh my god feed me, yes, give me whatever your secrets are. And what's what's super great about it is
Host 2 20:18
Like a whole test report here. Yeah,
Host 3 20:20
They have the whole thing they don't get, they don't give board files or anything. But I don't care, because I can, I can lay that out. But the 10 milliamp output from that 300 volt is actually way more than what we need, we probably need closer to four to six milliamps on the output of our so we're actually pretty good, I want to go a little bit higher than 300 volts. And I think we have plenty of play room to do that, because this output here, it's, you know, it's generated through a resistive divider. So I can just change some of the resistor values and get a higher voltage. And I looked at the duty cycle range on this output chip. And, you know, for producing 300 volts, it's around 50 to 60%. So if I want 350%, it, it shouldn't change too much. From what I found, I don't think that's going to be an issue. And in reality, some of the circuits we've already looked at, I need around 320 volts, so I don't need that much more. Mm, the the cool thing about this is the, the whole base of the switch mode power supply is based on the TPS four zero to one switch mode controller. That is just a really kind of Joe Schmo boost converter, the way they kind of get this extra voltage from is they put a capacitor diode voltage multiplier circuit in there. Which is, which is a really nice way of just quickly getting a bunch of extra voltage. Now, it doesn't necessarily do well with handling a lot of extra current. But in the end, I don't need a whole lot. So it works out really well for me. So go check out PMP 8621. If you want to see the the schematic that's kind of what we're going to use right now. And I've already got the schematic all drawn up in dip trace, I'm going to be moving it to a PCB here soon. But that actually kind of brought up while I was doing that schematic generation, it brought up some some interesting things. side notes that I want to talk about with this switch mode controller, because
Host 2 22:26
So on this on this PNP 8621. So I'm at the TI site looking at it. Yeah. And it's like, I hacked together board.
Host 3 22:34
Oh, yeah, yeah, absolutely. And it doesn't look like they spent much time on it.
Host 2 22:39
No, no, but so it's called Boost converter reference design. It just likes like a mess of parts, like stuff or likes, looks like parts are stumbling over other parts. And the best thing is, there's this note here, it says fully assembled board shown above developed for testing and performance validation only not available for sale. I would hope not, which means someone asked to buy this. So they had to put that there.
Host 3 23:07
Yeah, well, it's it's it's hand soldered, it looks like it looks like an engineering sample that was done in the you know, the lab, you know, a while ago. Yeah, that's for sure what that and I think that's why they don't provide the board layout files. It's totally
Host 2 23:21
A board that they cut up. And then they added that a diode. The multiplier, yeah, the diode capacitor multiplier, they added that on as a separate piece.
Host 3 23:34
Right, right. So it's, it's not it's not the nicest looking board, which is interesting there. But in the in the datasheet for the TPS 4021. They give good layout information, you know, notes on what to do. So I'm basically just going to follow those. They also do give some reference designs for just a standard boost converter without the capacitor do I have multiplayer, so it's basically adding that into the standard layout kind of thing. So their standard layout ideas are a lot more, I guess, you could say, professional and clean than the picture. Although I love this app note because it just looks like a dude slapped it together. And is like, Dude, you can do this, check it out. You know? And it also it's like, it just shows that regular engineers and regular people work at TI you know, and they also solder like you know, stuff together like we do
Host 2 24:32
Your own what they use what they designed is for
Host 3 24:37
It's it's a weird voltage range. It's a weird voltage range. It's also a weird current range. It fits unbelievably perfect with what I need it to do. So yeah, I wanted kind of a maybe it's pretty niche if he asked me, but so I wanted I wanted to share some some kind of interesting things that popped up. And maybe I'm getting something wrong here. Maybe I'm not I don't know. But these raise an eyebrow and make me say what's going on Di. Because in the datasheet, for the TPS for zero to one, I was going to make a footprint for it because it has its own footprint that or I didn't have that footprint in dip trace in it's an M SOP 10 Power Pad foot footprint, which is basically a 10. It looks like an soI C with with tighter pitch and one of the big pads on the underneath of the component.
Host 2 25:28
Yeah, like a T Soft Power Pad.
Host 3 25:31
Yeah, that's right. Yeah, it's, it's pretty similar to that. Here's the thing that's really weird about it. There's two separate dimensional drawings in the datasheet. They both have the same day. They both have different information on them with different dimensions. They both call out the exact same name for you know what the footprint is, but they are different. There are things that are different about them. For there's there's four pages in the datasheet that are basically duplicates, you know, in terms of what they reference, but they show different information. And I can't I couldn't find any kind of information on which one to use. Yeah, cuz
Host 2 26:13
It's got on page, let's see, what is this page 44, it starts the the Power Pad one, this is one that you're using with the external leads. And they mark it as the D, G q. So people that don't know, ti give their footprints like a reference three letter reference. That's right. So you basically you can look and see what that part number is by scrolling up in datasheet. So, so that's D, G, Q, and then you scroll down, and it says the recommended manufacturer layout and stencil openings. Cool. And you score one more, and it starts over again. And it's different D
Host 3 26:53
GQ, but it's still labeled as D GQ, right? And if you look up the ordering information, it'll say, hey, this part number, reference footprint, D GQ. And so I'm sitting here like what the hell is going on? Like, this is ridiculous. They are dated. They are dated, but look at the dates they they match the footprint. The actual dimensional drawing has the same date on both DG cues. I already checked that because I was like, well, maybe one's new and one's old. And it's not like I don't want to order it just to look at it and be like, Oh, okay, I know what it is. You know, that's kind of ridiculous. You
Host 2 27:27
Know what the way to fix this? You use the DRC one, which is the V sawn
Host 3 27:31
I could I could Yeah, I could but but we're probably going to be hand soldering this just because the other guy at work, who I'm doing this project with is, you know, we both enjoy soldering. So we'll probably just do that. That's why I chose the LEED version. Also, I want to be able to probe it if if necessary. So here's the way I got around this issue. I actually went to T eyes website for this part, I downloaded their footprint for it, which they don't have a dip trace footprint. So I uploaded it into a camp Eagle, I think. And then I converted it from Eagle to dip trace and then measured everything. And it actually reference references the second drawing. So for some reason, the first drawing is attached to that. And maybe there's some reason for it. And maybe I'm missing a note somewhere or something. I went through the date sheet a handful of times looks like I can't figure this out. I don't I don't get with why there's two, it doesn't make any sense. And so, you know, there we go, I was able to find an answer for it. And and I like the second dimensional drawing better, it has better thermal handling, the Power Pad is bigger. It references more vias and things like that. So I'm happy that I'm going with that, but it's kind of ridiculous.
Host 2 28:42
So maybe both are valid. Maybe, and one just has more better or one just has better thermal
Host 3 28:50
More better. Yeah, more better. I would you know, and I'd be okay with that. If they told me that. It doesn't seem like they there's a note anyway, that says if this use this, you know, we're engineers here, we just want the answer. So exactly. They so when there is one other thing, and it's kind of funny. The This package has a thermal pad underneath, which is there's nothing new about that they we've done 1000s of things that have thermal pads underneath. But if you look through this entire datasheet try to find anywhere where it said references that thermal pad, or references what to connect it to there is I found, maybe I missed it, but only one location in the entire datasheet. Well, technically I apologize to locations where it references the that thermal pad and it's on the drawing the dimensional drawing pages, and it says connect the thermal pad to the appropriate pad referenced in the schematic. If you go to the very first page, it doesn't even show a thermal pad. It they don't even talk about the thermal pad. If you go to the list of pins on there. There's only 10 pins there. should be, right. So there's no information about this thermal pad. And sometimes it's not acceptable to connect a thermal pad to ground. Sometimes they have to be connected to something else. So or floating or floating. Exactly. So I'm like, di, what do you do? And so what I did was actually went to their reference boards, looked at their layout and traced it out and found that it actually was connected to ground. But, you know, I couldn't tell that from the datasheet.
Host 2 30:30
Ah, I found it, it says it page 24 There's a schematic that has pin 11 on it. It's connected to ground.
Host 3 30:37
No. Yes, I am going to right now.
Host 2 30:42
PAGE 24. Figure 30. But why is it there and not anywhere else? I don't know.
Host 3 30:49
Oh, you Okay, it says PowerPad. Yeah, pin 11. You're right, you're right, it goes to ground. But look at every other schematic in the entire thing. Yeah, they don't have them. Look on the next schematic on page 33. And that's, that's a more official, schematic or official as in like it's drawn in the TI way. It has nothing referencing any Power Pad. That's just a and especially the simplified, quote, simplified schematic on the very first page of the datasheet. The front page of the datasheet does not reference a Power Pad at all. Okay, well,
Host 2 31:27
Yeah, there's a word I wonder if they bought this part from someone. Or it's actually ti part. I don't know. Cuz usually ti hasn't missed stuff like that. But maybe those as part of this guy's last day, it was a Friday 430 datasheet? Yes, I've been in layout guidelines.
Host 3 31:46
No, it's not, which is weird. Weird. So I, you know, to issues that I had to kind of like backdoor solutions for, you know, through panels. It's all good. That's weird. That's one of the things you have to kind of like get your ninja skills on is, if you don't, if you can't find the solution, you have to do wacko things to get it. Yeah. So there was only one other thing I kind of wanted to mention about this project is I haven't gone very far because I just actually selected this last night. But for the power amp, I'm going to go with the port number TPA 3116, which that is a Class D amplifier. And I can get 30 Watts from an 18 volt supply off of that it's also a Texas Instruments chip. But I haven't gone very deep into it. I just kind of like dug through the datasheet last night and I was asking, you know, is it really going to be able to do what I want it to? And the answer is yes. And hopefully I'm crossing my fingers here. I mean, from what everything I've looked at, it looks fine, but I should be able to do 30 Watts without a hefty heatsink on it. I will put a heatsink, like a little like glue on guy, but I, one of the things I wanted to do with this project was not have to like overly design stuff, I kind of wanted to just slap a bunch of stuff on the board, you know, with with good thought, but not have to go through all that extra stuff. And it's not like we're trying to make a product out of this. We're having fun with it really. So and I've never I've never done a tube style amp with a switch mode power supply. Well, we'll have some fun with it.
Host 2 33:26
It's really the best sounding thing you've ever heard in your life. Well, and
Host 3 33:29
So the project name right now, we're gonna be kind of simulating a Vox style amp. So right now we're calling it Vox in a box. And that's that's what we're going to go with for right now.
Host 2 33:41
It's pretty good. Yeah, it's pretty good one. Hopefully the project works out pretty well. If that cost. The amp looks cool.
Host 3 33:50
Yeah, yeah. And it's cheap. It's like three bucks. Something like that. Yeah. Cool. You want to you want to roll on over to the RFS? Yeah, let's
Host 2 33:58
Do the RFO. Cool. So this. This is from David Patterson. He emailed in after our simulation talk from last week. Yeah. And he suggested a piece of software for mentor called hyperlinks design rule checking.
Host 3 34:15
As soon as you say mentor would the thing that goes through my mind is like that's probably expensive.
Host 2 34:19
This is free. Oh, they have a limited free version that checks a lot of stuff. Very cool. It does impedance checking and differential impedance stuff differential pairs. It makes sure you don't have like floating metal islands from like a copper pore. So like you don't have a ginormous antenna on your ground plane. Stuff like that. It looks really cool. And apparently like the more you dig into it, like we were talking like simulating like EMF and stuff. Yeah, it can kind of do that with like cross like cross talk coupling and stuff. It can actually do that.
Host 3 34:58
That's actually really Cool.
Host 2 35:01
Yeah, that's the paid version though. Or they call it gold
Host 3 35:04
Version, identifying EMI issues. Yeah. Hmm.
Host 2 35:08
So I kind of want to give us a check sometime.
Host 3 35:12
Yeah, it looks like it'll also do DRC checks across the board. Which it never hurts to have a little an extra eye looking at things.
Host 2 35:22
Yeah. And it also works with it, doesn't it say it works with their their EDA tool stuff, but it also has non mentor work paths. So like Gerber's and stuff it will work with, I
Host 3 35:37
Think what it'll do DRCs directly on a Gerber.
Host 2 35:41
I think so
Host 3 35:41
That's actually really cool. I will have to play with that.
Host 2 35:46
Yeah, I'm gonna have to play with the two. It supports ODB plus, plus. And yeah, yeah, supports four designs created and mentor and non mentor PCB workflows.
Host 3 35:57
You know, that's, that's actually really, really useful for, you know, one of the things that's nice at a contract manufacturers when a customer's willing to give you their original design files, because then you can make changes if necessary, you can work with the customer to change things. But a lot of the times, you're not going to get that they don't want to share that or you know, for whatever reason, so you just get a packet of Gerber's. And that's great. But Gerber's are really difficult to, I shouldn't say really difficult, they're just annoying to modify. So if you could, you know, set up your own house DRC rules, and put that on Gerber's, which that's effectively what macrophage does, on the back end, you guys kind of have checks that go with that way. But for guys like WMD, this, this could be really helpful. I will certainly take a look at that.
Host 2 36:43
Host 3 36:58
If you say scripting, Parker's ears pop. Yeah,
Host 2 37:01
I love scripting.
Host 3 37:03
Well, thanks a lot, David. Yeah, thanks for sending that in. That's really cool.
Host 2 37:06
And then next was from Brian. Gosney. gozney. Yeah, Gosney. Yeah. And this was in response to the Jeep Wagoneer signal, Defined Radio project that I've been working on. And he has a similar project, but he's going a completely different direction. He's going more embedded. So he has a 1977 Dodge Colt. And he took the stock radio gutted it and he has a Arduino controlling a basically a bluetooth module. So you connect his phone to it and do all the amplification and stuff like that. He's not done with that project yet. But I'm thinking about getting him on to the podcast to talk about. He got into electronics because of automotive stuff. And I kind of want to know more about that. And he also pitched the idea of me doing fuel injection for the wagon with with the project called mega squirt, and I've heard of this before, but I've never really looked into it. And maybe you can convince me to do fuel injection on the wagon. Oh.
Host 3 38:13
So it sounds like you got a fellow auto electronic nerd here. Oh, yeah. No, I when I when I read this this comment come in the first thing I was just like, oh my god, there's another Parker out there. Mm hmm. Yeah, that's really cool, though. And actually see yet like the the whole the whole stock am radio thing is like, that's right down your alley. I mean, you did that. Oh, yeah. What a year ago?
Host 2 38:39
Yes. Yeah. So he's taking like the buttons that are, you know, the buttons we were talking about that you press and they the other one pops out? Mm hmm. That's on these style radios. He's actually using that for his his project and stuff. So I kind of want to see how he integrates that into his radio.
Host 3 38:57
Yeah, maybe you guys can share designs. Yeah.
Host 2 39:02
And then lastly, on the RFO is the open MV cam h seven machine vision with micro Python. And so the open MV cam h seven is a like open source micro Python computer thing. It's like it's a it's an embedded system. But it runs micro Python, which I think is very interesting. And we've had open NV on the podcast before it was Kibana who is a I think their co founder. I think that's correct. And he was on episode 27. If there is a bug, you can fix it. So go listen to that. That was way back a long time ago
Host 3 39:41
That was open and V was the old Mac fab shop.
Host 2 39:47
Yeah, old McWrap shop. Yeah, welcome back. So yeah, so they have a new Kickstarter for this new camera. It's twice as powerful. It's got more RAM. It's got everything. I think the cool thing with this new camera though is instead of having the sensor soldered onto the board, they actually have a module that you replace. So it's like a daughterboard that's got the sensor on it so you can replace the sensors. And so they have a, like the stock sensor is a normal rolling shutter sensor that you would get in your phone. And then they have a global shutter one. And so the difference with there is a global shutter basically takes a snapshot of the whole frame at once. Whereas a rolling shutter does it line by line. So if you have something fast moving, a global shutter will actually capture the image correctly, whereas a rolling shutter will have weird artifacts. If you just like YouTube, like rolling shutter effects, you'll see all the crazy stuff that you can like record with your phone. That's
Host 3 40:46
Cool. So I remember back in the day open NZ had exchangeable lenses. Are they still doing that? Or it does does the module have its own? Like each little plug in module has its own lens?
Host 2 41:00
The lenses are changeable. Oh, okay. Okay. So
Host 3 41:04
You can you can change the sensor and the lens. Persinger
Host 2 41:09
Correct? Yeah. And they have like a thermal sensor and stuff like that. So right, right. That's why I want to play with is the they have a FLIR sensor that you can get with it?
Host 3 41:18
Yeah, yeah. That's awesome. Yeah. Well, very good.
Host 2 41:22
So again, thank you, everyone for entering into the contest and bearing with I guess, just us talking about it all the time. Yeah, I was super happy that we had people enter and actually talk about it and give us feedback on the on the contest. And I just can't wait till the next one now.
Host 3 41:48
Yeah, I think the next one is just going to be bigger and more fun. Blink two LEDs.
Host 2 41:55
Blink two only two though. So if you have ideas, send them in on what our next contest should be. And I think that will do it for this episode. Steven.
Host 3 42:07
Yeah. And with that, that was the macro fab engineering podcast. We were your host Stephen Craig
Host 2 42:14
And Parker DOMA Take it easy. Oh, we've got to give a shout out to Josh. We can do that. Now.
Host 3 42:20
Let's give Josh a shout out. Yeah. Hey, Josh. Hey, what's up Josh? Dogs. We'll miss you. That's capital. all capitals. Josh. It
Host 2 42:30
Doesn't have to be all caps with us yet. Jed J OSH
Host 3 42:34
Believe that's how you spell it. Yeah.
Host 2 42:44
Thank you. Yes, you are listener for downloading our show. If you have a cool idea, project topic or contest idea that you want Steve and I to talk about and discuss. Tweet us at Mac fab or email us at podcast at Mac fab.com Also check out our Slack channel which we did not promote till now on this episode. If you're not subscribed to the podcast yet, click that subscribe button. That way you get the latest map episode right when it releases and please review us wherever you listen, as it helps the show stay visible and helps new listeners find us
Transcribed by https://otter.ai