On this episode, Parker sifts through marketing gimmicks for component ratings and Stephen discusses dual rail power supply designs.
PCB serial numbering? Parker and Stephen cover their thoughts on applying a unique identifier to PCBs in production for inventory and testing control.
On this Episode, Parker and Stephen talk about silkscreen markings on diodes and tracking beer drinking.
Figure 1: Selective solder 16″x16″ panel fixture.
Figure 2: MacroFab’s goofy T-shirt.
Parker is an Electrical Engineer with backgrounds in Embedded System Design and Digital Signal Processing. He got his start in 2005 by hacking Nintendo consoles into portable gaming units. The following year he designed and produced an Atari 2600 video mod to allow the Atari to display a crisp, RF fuzz free picture on newer TVs. Over a thousand Atari video mods where produced by Parker from 2006 to 2011 and the mod is still made by other enthusiasts in the Atari community.
In 2006, Parker enrolled at The University of Texas at Austin as a Petroleum Engineer. After realizing electronics was his passion he switched majors in 2007 to Electrical and Computer Engineering. Following his previous background in making the Atari 2600 video mod, Parker decided to take more board layout classes and circuit design classes. Other areas of study include robotics, microcontroller theory and design, FPGA development with VHDL and Verilog, and image and signal processing with DSPs. In 2010, Parker won a Ti sponsored Launchpad programming and design contest that was held by the IEEE CS chapter at the University. Parker graduated with a BS in Electrical and Computer Engineering in the Spring of 2012.
In the Summer of 2012, Parker was hired on as an Electrical Engineer at Dynamic Perception to design and prototype new electronic products. Here, Parker learned about full product development cycles and honed his board layout skills. Seeing the difficulties in managing operations and FCC/CE compliance testing, Parker thought there had to be a better way for small electronic companies to get their product out in customer's hands.
Parker also runs the blog, longhornengineer.com, where he posts his personal projects, technical guides, and appnotes about board layout design and components.
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.
Special thanks to whixr over at Tymkrs for the intro and outro!
Hello, and welcome to the macro fab engineering podcast where your hosts Parker Dolan, and Steven Craig, and this is episode 41. All right. Yeah. So this weekend is a big weekend for microphone. The Houston Maker Faire here in Houston, obviously, right is going to be this weekend and make McWrap will be there.
Yeah, this is the second time that will Yes, we'll have well, the second time we have a booth there. Correct. You guys have been there before we had booths, right?
Yeah. And we just kind of walked around with our T shirts on.
Yep. So ya know, at the Georgia Brown, pretty cool little place.
It's its little place.
Well, I mean, I'm saying that in comparison to the other Maker Faire. It's like the biggest
freakin building downtown. Yeah, yeah, exactly.
But you know, in comparison, we're a smaller one. But there's still a pretty big, pretty big following.
So what we're going to have there, a can't bring picking places and reflow. Of
course, yeah, this Okay, so this time, we're actually so of course, we have our booth with all of our, our lovely little jazz, but we're bringing some some extra little projects and some fun stuff to show off. I will be bringing my FX dev board, which we've been talking about for quite a while on the podcast now but but it will actually be bringing that and showing it off. So I'll have a guitar and an amp there and be playing on some some cool stuff a built up.
Yeah, then we'll be bringing a bringing the the EFI ghost detector, right. From paranormal
EDI plus, yeah, the EDI plus. Yeah, yeah, that's right. Yeah. From Michael Lyons who was on the podcast a couple episodes ago. Yeah. Something like that sort of fun, I think wasn't really that long ago. Yep. Wow. Okay. Yeah, yeah. So So Michael Lyons, he was on the podcast, his his ghost detecting device, because we'll be bringing that and showing that off.
And then we'll have the fantastic Eric was fantastic. Air quality real time tester. We'll be there. Oh, the tower, the tower? Yeah, that will be there. And
you're gonna be ready. You have one day to put that together.
And it's just it's an enclosure, man. I think I'll just take a Tupperware container and cutting a hole in it.
Yeah, that's super professional. But
it works. We're gonna we're gonna do is have we'll have like hand sanitizer because it basically detects VOCs. And, you know, methane, basically all the things, all them thing, all the things it can detect. And so we'll have a thing of like hand sanitizer that people could put on their hands and wave it over the sensor and a tower light up.
Okay, so it's good. It's the three color. It's the green, yellow, red light tower. Is it like, level of severity?
Yeah. So red is basically when you ping the sensor to the max. Yellow isn't in between green is you know ambient.
So so what? Where's this tower supposed to live? Its life. So
actually, this tower is going to live its life on the line. Oh, I'm actually going to remove the VOC detector and it's actually going to live on the conveyor, okay? Because we have a conveyor belt, it's a dumb conveyor. It just has sensors. And basically, it has like infrared sensors. Yeah. So as the board moves across, it knows where it's at. But that's it, it can't notify anyone that something's wrong. And so we're going to put this tower on it. So when it's basically the output of the oven, and so when enough panels fill up, it will basically trigger an alarm and say, Hey, I've got a lot of panels here, remove them or stuffs not going to come out of the oven.
You know, it's a good thing when you have so many panels that they're lining up on the exit of the reflow. Oven. Yeah, that's that's a good problem. That's a good problem
to have. Yeah. Yeah. And then. So going forward on the FA RT project. I want to put the tower on like, above the bathroom doors. Sure. And then have them hooked up to the vent fan. Fans so you can you could detect all those voc Yeah, all those VOCs and that way you also know like, hey, you know, I kind of need to go to the bathroom, but it's in the red, but
don't go anywhere near there. You know, I
can hold it for an hour.
That's amazing.
Well, cool. Yeah. So yeah, um, I fixed that board.
Yeah. So moving forward on that project. Yeah. Getting getting really close to doing an actual launch. Yeah, I
got to see the rough cut of the video. Yeah, so awesome. So Josh
has been doing the video for us. And it's just it's killer. It's killer so far, I can't wait to post it to everyone. Because it's just it's What we were looking for, and it's got the right level of goofiness in there, yeah,
it really captures the spirit of McWrap. And map at the same time.
Sure, yeah. And you get to see my ugly mug,
half the video. Anything else about FX airborne?
Well, you know, as we as we keep getting closer to launch date, I'll keep giving updates on it. Hopefully, it'll be very soon Keep your fingers crossed. Been doing a bit of building for a repository and a blog basically, such that when people actually get the dev board, they can see some creations that I've made, they can download templates and make their own and put them up. So we will have some information on that. On the on the blog post tomorrow for the for this podcast, I can show some some of my progress on that.
Have you come up with a a domain name for the blog yet?
That's a hard one. No, the answer's no, that's the hard. That's a hard one because I want it to be just right. So we've nicknamed the breadboards that go on the FX dev board. So the actual breadboarding surface, we've nicknamed them butter boards. So I'm going to see what version of butter board I can I can actually snag and see if there's anything around that that might work. So we'll see. Cool. So also some cool stuff this week on selective solder. Okay, yeah, that machine are selected solder device, the the machine that's basically a CNC with a solder tip on the end of it. Yeah. Or solder? Trotter wave. Yeah, yeah. It's a Yeah, it's CNC solder wave that basically, so So Parker designed a 16 inch by 16 inch jig. Yep, that allows us to accept our largest panel size. And we got that working today on the machine, which is super cool.
Yeah, it's all nice and calibrated up and ready to
go right before the right before we came over here to record this. I tested the first panel and it's looking great. Would you say it's been? We've been that's been on the books to do for a long time. Yeah, basically, all of our machines were trying to get them to be able to work with our 16 by 16 unified panel size. Yeah. And this is kind of the last piece of the puzzle. Now all the machines can use the exact same size of panel which way thumbs up on that?
Yeah, no more adjusting conveyor. Why widths and stuff. Right, right.
There's, there's a little bit further to go. Well, okay, so So first of all, it's pretty cool. The porker designed a jig effectively that holds our panels, because our panels all have a border on them that have a handful of eighth inch holes or is a quarter inch, its eighth inch, okay, eighth inch holes. And they kind of all SNAP INTO THIS ONE jig style. But but there's kind of like a unified frame for the jig. And you just modified slightly for different variants. There's some that can go through a reflow oven. There's some that can go on or selective solder. And we also have an adjustable one for varying panel size handle sizes now. So yeah, a bunch of cool. Different jigs are all coming out all at once.
Yeah. And I'm hoping next week, I'll be able to show off those those fixtures a little bit more. Yeah. Like having a lineup and I should try to find the prototype ones and like have like an iteration thing.
We have the original. Well, there was a Jigga destiny.
Yeah, the original Jigga Destiny somewhere. I think it's in like, been kind of taken apart. Yeah, parts. Yeah. But it's still there.
Yeah, but yeah, that'd be cool to show that and they're all anodized color coded, right.
Yes. Yeah. What part of the process they go in?
Yeah, it's it's pretty cool. So I'm excited to finally have the selective solder up and running with our 16 inch panels.
Yep. So the the LED clock I've been talking about? Yeah, yeah, yeah, I'm designing. So I actually started doing a little bit of work on that, like actually designing the segments completely. And so I laid it out and looked and so the each segment is three inches by six inches. Okay, this one's pretty big. Yeah. So say hold digit would be about 13 to 14 inches tall.
That's pretty big.
That's pretty big. I'm using macro fabs. Oh 805 LEDs, because their house parts, so they're fairly inexpensive. Yeah. My first draft of a segment use 260 of them. Oh, geez. And then I'm like, I looked at it. And I'm like, Wait, I got to do some math first. Make sure this is actually possible. Like just power? Yeah. Because 10 milliamps per led, which is like, oh, yeah, no big deal. So until you have 260 of them.
And then you have potentially multiple segments lit up at once.
Yeah, so it could be all you know, In theory, you could light the entire panel up, right? And so you've got eight, eight digits because you want to have our minute second milliseconds.
millisecond. Yep. Okay.
And then, so you got 56 segments. Okay, that point. Yeah. And then, you know, each LEDs 10 milliamps. And so each segments with draws about 2.2 amps.
Assuming Yeah, for for 200 and some odd Yeah. LEDs? If Okay, so if it's on it goes from zero to 2.2 amps. So total
You're talking like 120 ish amps. At 24 volts.
Why are you not doing this? You need to you need to make that
because it's three kilowatts.
24 volts. Run. No, run it off of 240 volt.
And yeah, that's actually I looked and tried to find like, Can I get a 24 volt power supply? I can do this. Oh, no. Only only something you know. You can? No. Yeah. But they run off to 40. AC?
Oh, well, okay. Sure. I mean, are they like, huge industrial control?
No, all the main my meanwell and they're designed for like C and C's.
Wow. 100 something is? Yep. How much have they got to be like $800?
Ah, about 350. Really? Yeah. So I'm actually thing about just cutting the LED count by a quarter.
But still, I mean, you cut it by a quarter. Do you? If you cut that by a quarter? Do you just cut three kilowatts by a quarter? Yes. So it's still a couple 100 watts.
Yeah, well, it's gonna be bright and expensive. No, actually, they're pretty inexpensive to make. It's like no,
no expensive to run.
Oh, well. No, that's that's up to Josh. I don't have to worry about that. I just gotta get built.
is all that matters.
He's gonna turn on it just like the entire room will be red. That's amazing. You got to think is if you cut. Let's just say you did. 260. Right. Is a full blown stuff. That's that's like 10,000 LEDs? LEDs.
10,085 LEDs? That's a no, that's two reels. Two reels and 5000 on a reel. Two full reels of LEDs for that. And 56 segments. Yeah. We with segment that size, you could probably fit. What? On a 16 by 16. Panel. What probably fit 2520 Isha? Yeah,
so the three panels worth of three panels worth of was built over a course.
Wow. So we Okay, so is your plan to use just just raw boards and mount them to the wall? Or do you want to have like a shroud around them.
So it's going to have a piece of plywood that the segment's get screwed to Okay, with standoffs. And then we'll take a piece of plexiglass and cover the whole thing with that. That's that's a frosted piece of Plexiglas. And so that will deform a little bit. So when it's off, it just looks like a ugly piece of Plexiglas on the wall. When you turn it on, it'll look sweet and the look
like a glowing piece of ugly wall. Yeah.
Yeah, that's that's where that projects at. Still trying to
sound like you're still on the drawing board from from your calculations that I had haven't designed.
I didn't route it. Because once I put all the LEDs down, I like stood up for my computer and was like, Oh, no. What have I created?
We wait, do you have? Do you have all of those LEDs in parallel?
No, no, no, they're in
like a series parallel company series
parallel combination. And they're 12 in a row. Two volt drop. For 24 volts.
We were Whoa, whoa, whoa, whoa, whoa, please tell me you have a resistor in line with them. Not only that, Oh, come on, dude. be fine. Okay, so Parker and I had been arguing about this for a long time. Parker is absolutely okay with just putting an LED across the power line. If the voltage is within its width or drop in his four drop range, and that's fine. I've never been okay with that. So
what resistor what? So if you have a three volt drop resistor, a blue LED, and you have a three volt supply, what resistor would you use?
I wouldn't use that led. It's that simple. I pick one with a different forward drop.
But what if you need what the customer says I need blue.
I tell them they're stupid. You can't do that. That doesn't it doesn't work.
That's it. exactly how it works. No that is not that works. All right? Tweet at us see who's right
it's not how it works. Move on to the arm. No, no,
no, no, I want to set up like a I'm going to set up a power supply tomorrow at 1.5 volts with a red LED like a cheapy red LED. And I bet sure how long is it gonna keep running for
I know it can work that way. Don't get me wrong, I know it absolutely can work that way. But that is not an optimal way. That is not the way you're supposed to have something that limits the current and forces the current to be within a range just allowing the the bandgap of the LED to decide that is kind of just well that's nothing for destruction. So you've
used the online led calculators before right? Sure, okay. So those all they do is burn. So if you have a five volts and you drop into three volts, all it does is burn to two volts to the resistor it that resistor is not actually limiting it to heart and milliamps
No, it is not it is not limiting it to a hard 10 milliamps, but it linearly limits the current if the current is to grow for any reason, but if you just have a diode across it and your voltage starts to climb for any reason whatsoever, that diode just goes bring it on Give it to me
that sounds like a bad analog design on the power supply.
Putting a diode across the power supply line sounds like a freaking terrible analog design. This is getting heated I love it
see all you got to do is put the one across the diode it works
oh my god digital guys. Oh they just destroy me.
Okay, see what else is on this list? Yeah, let's move on. Let's go to SOCO. Fr 300 repair. Okay.
And for 300 The Hakko it's a D solder gun. More than that it was my wedding present. Awesome. Yeah, no, no. Well, to yourself sort of to myself because because you just use a gift card debt, you know, no, no, no, no, what it was was was my wife was like, she we honestly had not known each other super long before we got married. And so she was like, I really don't know what to give you and I was like, let me just go buy something for myself and I'll say it from you. So I bought myself a soldering iron for my wedding. And and I was like hey, thanks I sent her a picture of it. I was like this is a great present thank you so much. i But But ya know, so I showed up on my shop the other night and honestly, that's that thing has been one of the best tools I have I built a holster for it that connects to my bench because I use it all the time. I showed up the other day and the the heating element was just dangling from the front of it and mind you it This isn't like a like a like a radio shack iron this thing cost me 350 bucks. So I was kind of I was kind of pissed when when I saw that. So we tried to fix it Parker and I Yeah, we started with with super glue.
That's why you soldered all it all back together.
Yeah, yeah, yeah. So it had its cut some they used one of those little tack weld so it's just about welding the back end of the the heating element has some some like brass tabs and they they spot welded wires to it which somehow all four of the connections so there's there's two heater element and two I guess thermocouple elements yep that are that are connected there. They all broke when this thing fell apart which I think a buddy of mine did whatever well that whatever but regardless, everything broke on this so I tried soldering all those wires back and that was a giant pain in the ass but but got that back together and now I got a super glue the my heating element back to my my my Hakko super glue does not work very well at 450 degrees. It doesn't it just and it smells
terrible and makes your eyeballs go Yeah.
So so we try JB welding it.
JB Weld worked okay for about about an
hour. And mind you we're all trying to do this while repairing Josh's SpaceX Yeah, because we said last week that we're all that hey, we're going to Steve shop to fix the space echo Well yeah, I mean half the time is just sitting there trying to glue my soldering so so here's the thing. All said and done I said you know, screw it. Can I just go online and buy the parts for this? And surprisingly HECO has like
everything you can buy the like enclosure for it. Yep
20 bucks for the for the enclosure which is dirt cheap for this. The funny thing about all of this is they have basically everything you can buy the PCB they control PCB for this. You can buy everything else except for the one part that is broken. Yeah, for some reason I cannot buy that one part.
I bet you recall the called Haku up and be like, Please sell me. Yeah, I
guess I guess I shouldn't say they don't sell it. That's the one part they don't broadcast on the website. Yeah, I was
actually really hoping they sold all the parts. And then we could like tally up the total and see how much it would cost like to do meal together. Yeah. Because that was what, what for what Henry Ford said that you should be able to buy replacement parts and build your own model T for the same price of buying them all see? Really? Yeah,
no, remember that. That's cool.
I might be misquoting him, but I'm pretty sure that's true. Me.
So yeah, I gotta I gotta somehow repair my fr 300 or Josh will never get his space echo
SpaceX Oh, it's almost done. Yeah. All right there that one board is 100% done. The other board that's inside. It's all D soldered. And it's about halfway through its recap and then the soldering iron. You know, took a dump again. Okay, so our fo RFO Yeah, finally getting there. This is a little quick one. Visual Guide to the best hacker T shirts on Hackaday. This is a top we don't really talk about shirts on macro fab. Okay, but I'm going through the list. I did not see a matter of engineering shirts are really awesome. All your base are belong to us. Oh, yeah, sure. Cuz that's a like, no one. I think they will have taking pictures at some conference or I think that the the whatever hack conference had been at Sure. I don't think it's DEF CON. But whatever was been going on. Yeah, that took a lot pictures and no one was wearing a Mac fab shirt.
sucks. Yeah, we need to fix that. Yeah, we gotta fix that. Yeah. Sounds like we need to complain. Yeah.
Who do we complain to about wearing a t shirt out of conference? Yeah.
Sweet. And you get you get the link here for all that.
Yeah, they got some pretty cool shirts there. The cool thing is they actually did some research on the shirts. So a lot of them have links to where you can buy. Oh, we really need a Mac five shirt on there. Yeah. Well, we don't sell the manufacture I guess.
You can get a Mac fab shirt. If you place an order in a big order. If you place a large enough order. I do not remember what the the number the monetary value of that is. Yeah, I don't remember what that is off the top my head. But what is more than one PCB. I guarantee you that?
Well, especially since you can buy a PCB at macro fab for less than a cost of a T shirt.
Well, okay, so we are considering on the FX dev board. It's not set in stone yet, but we are considering a pledge option where you can get a shirt. Don't hold us to that yet, because we haven't confirmed that but we're considering it.
Do I have to design a shirt or we're going to use our old shirt design?
I'd like our old shirt designs. They all your bait, all our base junction are belong to us. I'd like that. So
what if I made an ethics board? Inspired one? Hmm. Yeah. I'm on the t shirt committee here at McAfee. I design all the shirts.
So there's like 10 people.
Hey, it's a committee. Right? Okay, um, and the last RFO Samsung you know, Samsung can't catch a break. They had the the note exploding. Now they have washing machines exploding.
Wait, wait, wait, wait. I have not heard this. Yeah,
the the top loading washing machines and if you overload them, and then have them do high speed spin, they come apart and
explode. Okay, so this isn't like another battery thing? No, no, no, no. They literally rip themselves apart. Yeah.
What the quote is the washing machine top can unexpectedly detach from the washing machine chassis during use posing risks to injury from impact.
And most everywhere.
Oh, poor Samsung.
You know, they're they're big enough that they'll survive but it's still it's like they're not Yeah, they're not going to get a break here. No. And and all the freakin images have their their exploded notes as
well. I think I think on the note thing is that's gonna be the end of that name brand.
The note? Yeah. The next thing we call it was the Note seven, right? Yep. So it was fairly mature. No.
Oh, you mean the brand name? Yeah, the brand name? Yeah, the brand name. Sure. Yeah, yeah. But um, yeah, whatever Samsung phone comes out next, it won't be called the note. So it'd be called like, the nope, no, not What's the what's the thing for note that'd be called like the
journal the journal
or the posted
that Samsung posted? Yeah. The diary that there we go. So they chucked it all up to the note thing. That was all thermal expansion, right.
That's what last I heard was basically the battery's slightly swelling, and there was not enough space for it to swell into.
So so they just decided, I mean, the batteries just decided instead of swelling. I'm just gonna catch
on. It would burst the barrier. Yeah. And then yeah, and then it's game
over from there. Yep. That sucks.
Yeah, well, we're gonna do
so like, there's, there's all those little gotchas where it's like, your, your device can work perfectly. And you can go through all your testing and you still might have missed a small thing. Like I was watching the ever ever checkout SciShow on YouTube. Never heard of him. Check them out. They're really cool. They just do some like really nerdy stuff. And they usually like two or three minute things. They have a they have a sub channel called SciShow Space. And they were talking about some some probe, I can't remember which one it was, maybe it was Voyager something. But it's, it was way off of its predicted chorus after you know, 30 years or something like that. And and the reason it was off is because they didn't take thermal dissipation into account the original engineers. So the processors onboard the the electronics onboard, emit just a small amount of heat. And that was enough to push the probe and it's way off course now. So those little tiny things hmm, like thermal expansion in batteries that you just don't necessarily think about, they can end up being a Note Seven.
Second thing now,
you'll be out seven bit yeah, and Note Seven.
Yeah, this was episode 41. Thanks for listening to the macro fab engineering podcast. We are your hosts, Parker DOMA
and Steven Craig later guys, take it easy.
On this Episode, Parker and Stephen talk about silkscreen markings on diodes and tracking beer drinking.
On this episode, Parker sifts through marketing gimmicks for component ratings and Stephen discusses dual rail power supply designs.
PCB serial numbering? Parker and Stephen cover their thoughts on applying a unique identifier to PCBs in production for inventory and testing control.