The quest for the right connector for a project! The right of passage for any hardware electrical engineer starts with a connector catalog.
This is the last installment of Stephen's 'Adventures in Injection Molding'. We are going to recap the entire two year sage and close the book on it.
The Jeep Prop Fan project rides again! Well some iteration of it at least. Lets design an open source PCM (Power Control Module) for automotive apps!
Figure 1: Older prototype of the Jeep Electronic Control stuff. Showing the Large VFD
Figure 2: Old Kester 44 solder that Parker has 20lbs of. Set for life.
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. We are your host, Stephen Craig and Parker
doing. This is episode 93. So episode 100 comes out at what? December 28?
Yeah, that's 20/29 29th 29th. That's the the last podcast of the year is episode 100.
Yeah, amazing that we're, we will get there was one of us dies.
Let's try not to die.
But so we're thinking about doing a big like q&a.
Yeah. So just we have a couple of weeks until then. So we were thinking, people, just if you want to put in your your questions, we will answer them and they don't have to be electronics related. They could be anything you want. And we'll pick a good chunk of them. And we'll just go through it on the
podcast to be the macro fab comment Show episode one.
Every 100 Yeah, yeah.
So yeah, it would take it would take 100 years to get to 100. Or something like that.
Yeah. Yeah. Whatever. Oh, yeah. Sure. Okay, whatever. So the Yeah, so write in your questions to podcast at macro fab.com. And we will get all the questions tallied up until that time, hopefully, we will get more than like, two. I hope. So, yeah, look, looking forward to that. I think that'll be fun. Because, and you know, what, actually, here's a suggestion. why don't why don't we try to keep them? secret from us? I Iris are our marketing manager here or director of marketing. I should get all the questions, so we don't even know them until we show up. Yeah, I think that was like, that would be a lot. And
you can ask us the questions. So we can mic you up. And then yeah, yeah, let's do that. Yeah, that sounds great. And then episode 98 is going to be the Star Wars special. That's right. Two weeks before the second annual Star Wars Christmas special macro fab engineering podcast, whatever it's called. We probably won't do video this year.
Because it was so successful. Yes. So yeah, go check out
our the macro fab YouTube channel. Yes, we have one. I think there's like 40 people have maybe have clicked that thing. Ah, it's a little bit better. It's like 200. Oh, that's actually surprising. It is like two hours long. That was like, what episode 60 something earlier and that is something like yeah, I split up the audio into four parts that were that the audio did really well. While people liked it. Oh, yeah. And it was fun. So wonder it again and what the episode will cover will basically be what we want into the what we want to see in the new movie, which is episode eight.
That's right. Yeah. Because we did it right after or no, we did like the day before. Rogue One. Yes. Last last
year. Yeah. And so we'll do like what we want to see and we'll probably talk about the tech we saw in Rogue One. Which is like the Death Star and stuff like that, right. We talked about this a little bit, but we want to talk I want to talk about more like how they used it in Rogue One night. Yeah. Same thing in the in Episode Seven. Like how they use Death Star Killer and stuff.
Start Death
Star death, whatever.
So I actually did just look up the the it's
like YouTube, how to name things in Star Wars is take star death killer destroyer and dark side. Put it in a bucket. Shake it up and like get three items out.
Yeah. Well, it has to be more than one. Yes. But it could be up to like five, up to five. Yeah, so just like whatever it until it works. Yes. So yeah, we have 191 views. He like 190 Those were like the first week that pops out. Nobody else has watched it. Yeah.
So yeah, no video this time. Now. It was a lot of fun. It's just that was the video was a lot of work. So yeah. Okay, so we have the Star Wars and the episode 100 super special. Right q&a session. Once
again, get your questions into podcast at macro. fab.com. Yep. Alright,
so last week, I talked about the Jeep electronics. And so I worked a lot on the cabin board. So there's gonna be two boards, one that's inside the cab one side is inside the engine bay. And I got most of the, the cabin board done. I got all the power done. And I got the microcontroller stuff done, which I had to copy and paste because I'm just using the parallax propeller. So I have all that stuff designed. Copy paste that. I have an IMU on there so I know what angle the board is at and what direction you're going. So you have a compass Yeah, important, right? Yeah, a critical. Yeah. And I actually was gonna put like, since I had the IMU in there and has a gyroscope, I can figure out what angle the Jeep set. And so I'm gonna have like, I'm like, I don't know how how you can test that, like, when is the breakover when your Jeep falls over so you have like, five degrees on warning before you flip it over.
I had a I had a professor once. It was physics to physics one, I can't remember what it was. If you if you look at the shadow of the vehicle, if the shadow of the vehicle, when it's tilted is beyond the centerline of the of the center of mass, then it'll tilt.
But you start to compute the center of mass. Yeah, right. Yeah, I can't do that in the jeep.
The Jeep center of mass is right, dead in the middle way down to the ground. Right? Wish.
Actually, the weight distribution on a Jeep, an older Jeep like mine is actually like 60 4060 at front for Yeah, it's super front. So it's that? Well, most cars are like 8020. Yeah, so it's actually fairly balanced that way, but I don't know how high it is.
Oh, and you lifted it a bit. Yeah.
And it's got like armor and stuff. So it's probably even worse. But yeah, so I don't know that but I might just like, like, keep jacking it up until it feels like it's getting close and be like, Okay, that's gonna be the safety margin. But for the power to 12 volts comes in and actually on car car. Power. It's like 14 volts because the alternator. It's like 13.9. Yeah, I really wanted to get down to it. But I just had 14 went and was doing all my calculations. Oh, student 14 volts. So I'm using an L. I got
to interrupt you real quick. Yeah, we got Did you know we got rid of our old oven today. The old electro vert the old electrode is gone. Ah, hold on God. But it is this is relevant to the story. And it just came to mind. You're talking about things tipping over? Yeah. The guy who came to pick it up, came with a forklift. And he had to put the forks together really close to each other because I had to pick it up. On the short end. Yeah, long. Picking up hot dog style. Yeah, hot dogs out. Yeah. And so he got extended forks, and then put them really close together. And in the way this this kind of deal worked with this guy who is picking up our oven. It's it's a it's kind of a piece of junk. It's been sitting around here for a long time, because we got a new oven and we just set it aside and whatever we work to deal with this guy, but the deal was he just comes and picks it up and weren't, didn't really want to help a whole lot because it's that's part of the deal. So he picks this thing up, and I'm sitting outside watching him. And that oven just starts to tip. I'm just like, oh, and he slammed the forks down because that thing was about to go right onto his face.
And there's like smoking cigarette.
Oh, yeah, that that actually would have been a lot smoother. But I mean, luckily he saved it. But I was just like, oh, cuz it was it was about to fall.
Yeah. That that electric oven got us. That was like three years of production.
Oh, yeah. Yeah. And we wrote it hard. Yeah.
There's electric for Bravo. 4050. Yeah. For his own oven. And we bought it used for six grand. I think I think you know, six grand delivered.
Okay, you got well, you got six grand worth of work out of that thing. Easily. Yeah, yeah. You got way more so it's
an oven. That's it's it was lead free certified. Yeah. But it was like you had to run every heater at 100% all the time to make them. Yeah, it was both through walls. Yeah, it was. Yeah, it was definitely not. Yeah, it felt like it wasn't designed for it. It was just kind of shoehorn into lead free. Yeah, so it's not like our current our current oven like doesn't even break a sweat doing this lead free stuff.
No, no. Yeah. Well, we certainly upgraded and I bet you that old oven if you replaced all the the blowers on it, and all the capacitors and then ran a lead process. That thing is probably a trooper. Yeah. Yeah. So but the whole tipping of large items that came on, I gotta tell you about that because you probably didn't know No, no, I didn't. It was pretty great.
I wish I knew that. I knew was going away but I didn't know what's happening today. Yeah, I wanted to send off
Oh, like a Vikings. Yeah, as the guy pulls away when you launch a flaming and on top of that, like it wasn't like taps. Yeah, yeah. It was like, yeah, it was a small enclosed trailer. It was. It was less than an ideal situation. But whatever. It's something you got to work. Oh, yeah. No, yeah. Now he's got to get out of the trailer. Ah, that's on them to take care. Yeah, no, but yeah.
So yeah, so Okay, back to the G Yeah. So my five volt regulator, I'm using an LM 2267 B, TJ five point o n o p
B? That one
that one. Yeah, it's a TI switcher. I just use the TI web bench to Oh, yeah, you get the parameters. Yeah, it's like 14, yes. 14 volts. And I wanted like three amps, and which was on the high end. But I'm still like, I'll get to why I need like that much power. This thing? Because it's like, the switcher that it told me uses a five volt switcher. But it's five amps. Sound like that gives me plenty of headroom for why I want to do with it. Because I have a for the display of a 40 by four VFD. Oh, so it's it's pulling some juice? Yeah, I think pulls about 800 milliamps at five volts. Yeah, so it's quite a bit. So I wanted some extra headroom, which slide pick three. And this seems even more headroom with five. So it's like even better, you know, they won't be stressed as hard. So you know, less switching noise and all that good stuff.
You know, okay, so that's one of the things that's actually kind of annoying about switch, switch mode, power supplies, you gotta love them, because you can get almost anything you want out of them. And most of the time, they're, they're really killer, but you have to have a pretty good idea of what your load is going to do. Or your efficiency is just absolute garbage. Yep. So like, switch mode power supplies give you like so much control, but you have to know more about your circuit, you have to tune it. Yeah, you really have to tune it. And so like, like with one of the this guy, I bet you since it's can deliver five amps, it's probably five amps at like 75% efficiency or something like that. But if you're asking for 10 milliamps, it's probably only like 10% efficient. Yeah. Which isn't a problem, you know, cuz
yeah, this guy in the configuration I have it set up is like 90 ish percent. That's pretty good, actually. Mainly because I didn't want to, I wanted to switch through here because I didn't want to go from 14 to five volts. And in heat loss. Yeah, yeah. And yeah, just dump it all and have to figure out how to heatsink that
well, and that's the biggest problem with the linear regulators.
Yeah. And so for the 3.3 volt line, though, I'm going with an LTO because it's gonna be all digital circuits. And so I wanted something a little cleaner, and LBOs. And so it's only from five to 3.3 volts at that case. So it's not that much power drop, and it's only like, only need like, like 100 milliamps, something like that. And this is 100 amp, you know, LTO it's a ADP three three ba K CZ Dash 3.3 Dash RL. I think Analog Devices makes us one. This is like my go to lto. It's like a camera with that package is called Deepak. No, it's a ti? Ti Oh, 223.
Isn't that pretty? Similar to three?
No. DPAC is like a, almost like a to 220 That's just laid down a down? Yeah. Almost. People were like, That's not like Baba, it's almost like
you're anticipating. Excuse me? Sorry, you were incorrect or incorrect.
Quote, it's the same close to the physical dimensions. No, this is like that. Um, it's like half the size that? Yeah. Yeah. It still got a, you know, big thermal pad. Good stuff.
What's. Okay, so for those, I guess, just a real quick for those who don't know, for the linear regulators. The output juice that you have coming from a linear regulator is regulated to whatever voltage the regulator expect that? Yep. So if you have like a 7805, that's a five volt regulator, and you'll get five volts. If you have five volts at one amp coming out, then you'll have five watts coming out the output? Yep. But let's say you put 10 volts into it, that 10 volts has to drop to the five volts on the output with the same amount of current going into the view if you're doing
five volts at one amp output. Yeah, you need to do 10 volts at one amp in That's right. Yeah. 10 Watts minus five watts. So you have a five watts patient, right?
So your whole system is guaranteed inherently 50% efficient at that point, yes. Only half of the juice that's going in actually hits the device or the load that you want half your power is key, right? So that being said, what's the highest that you've ever hammered a regulator with the highest voltage drop across the regulator?
Oh man. I don't remember the highest drop I remember the most sketchiest thing. Please share so the when we were doing all that Raspberry Pi stuff, I had a the first thing I did was I was the Raspberry Pi with the lbds converter on it. that drove a LCD display. So the LCD display needs 12 volts. And so I wanted this whole thing to run off one supply. So I had 12 volts coming into the board, and then I need to drop it down to five for the Raspberry Pi. And so the five volt regulator on there, I suspect at like one amp is that if I was B, that'd be enough. It was enough except that the board wasn't big enough to dissipate all that heat. And so I had like, I stack pennies, because that's the only thing I had I stacked pennies on top of it. And that worked
as a heat as heat sinks. Yeah, that's great. Yeah, that's fair does, it would be it'd be, and they
were just laying on I didn't have thermal paste or anything. Remember, I'm down in like, I'm like on vacation. You're trying to test this board out? I just have Penny stacked on it didn't depend. He's get pretty hot. Oh, yeah. It would work for about 10 minutes and then start thermal cycling. Oh, yeah. But without it it would thermal cycle in like 10 seconds. So the pennies did enough to where you can get some testing done. And then you turn it off. Let it cool down. Fire it back up dust again. Yeah, yeah. All right. That would been seven Watts dissipation over a tiny tiny way under sighs regulator. So it was like if I ran the Deepak it would have been big enough. But this was a whatever that size is. It was the same package. Is
that a two to six or whatever you said? Yeah. Yeah. Yeah. No.
T It's a SOT SOT two, three years, something like that. 232
It's a big side. Race. Yeah. Not not the little guy with legs? No.
Is it is it's half the size of a to 220. Okay, I can't remember what it is. Anyways, if you look up the ADP three, three BHK. It's that same package? Okay. Yeah, it's the same guys that Yeah, I think I actually was the same chip, except it was the dash 5.0 which is the five volt
one. Oh, yeah.
So what What about you then?
Uh, so for anyone who's ever worked with high current, low voltage, linear power supplies, you know, that the, you start to get into some really funky problems when you have to have a transformer that supplies all that current, because you start getting into all the effects of the actual winding resistance in the transformer. As you start pulling more juice, the winding resistance starts dropping your voltage. So you have to do all these gag of it. You said a lot, actually. And so you have to back calculate all that. So so in a project I was working on, I needed 12 volts, one and a half amps. So what 18 Yeah, 18 watts of power. And luckily, it was it was just everything was DC and it was not changing. So I knew that was going to be fixed. But I didn't know all of my transformer specs. So I ended up going with a I think it was like an 18 volt transformer. So once you rectify that up, you got like 22 ish yet, well, yeah, once you read, and then sag it down, you get somewhere in that range. I overshot. And so I've got an LM 7812, going from 22 down to 12. But I had two diodes on the ground pin. So it was actually I'm sorry, one diet. So it actually bumped that up to 12.6. Yeah, you're floating, floating a little bit. So 22 to 12.6 at one and a half amps. That thing got hot real fast. Because it was trying to dissipate however many watts but I only actually ran it that way for a real short period of time to make sure that it actually regulated. I put some dropper transistors across it. The and those guys were like the brute force guys. So I limited the 7812 said it only got like 50 milliamps, and all the transistors in parallel with it took all the brunt. But for a little bit of time I had I had one of those to 2015 Watts
15% efficiency.
Oh, yeah. It wasn't very good. But it worked. And it's, it's running continual. In fact, I think you and I actually repaired that circuit. That was in one of the amps that I that I built a while back. Remember the heater circuit? Yeah.
And we could. So this is back when? This was like two years ago. Yeah, it was. We were had band practice in your shop. Yep. And the your your you would be playing and then like, basically like his guitar would just go silent. And all you could hear was people banging on drums and the bass. Yeah. And then the guy the guy playing while y'all were switching between rhythm and lead. So it's like whatever. So you can't say lead or rhythm guitar is the other guitar she could use. So Stephen would go quiet. And so we're trying to figure it out and I just took the box fine. I was on the ground and stuck it in front and then it started working again. I like it that way for like a month. And then it's like that's not working to take it apart. And it was because that regulator was just like cooking
that but that regulator had been a trooper for like five years. Yeah, yeah. So we replaced all the capacitors in that circuit and that that transistor and the regulator network, but
the thing is, though, is it was rebuilt how that way and so it will fail again. And
then yeah, but but I'm not a but I mean, I was hammering it for hours. So yeah. So yeah, that's, that's the most I've done.
Okay, back back to the Jeep back to the Jeep electronics. So the VFD or stock mount? Yeah, it's a four by 40. Character display. So it's like a, like a normal cheapo LCD. But it's liquid crystal actually style. Character display. Yeah, but this is a four four lines tall, 40 characters wide. It's pretty large. The part number on that is somebody it's my North talkie. Yeah. At some tag practically
every VFD nowadays is north. Okay.
Yeah. It's C u 400545. Dash, U. W, one. J,
you always have the most interesting part, partners. Thank you, Parker.
And I actually I started using this, this display years ago. And so I decided to repurpose it for this because I haven't lined around and you have libraries written for it. Yes, I wrote some prop code make it work. I think it's a if I remember correctly. It's parallel slash serial. So you'd like double load stuff in. It's kind of interesting how it works. I'll post a PDF, I guess. So people can look and see what the protocol looks like. I guess you can post code too, because it doesn't matter. Yeah. Well, that displays fairly expensive. I think it's like 150 bucks on Digi key. Oh, I got it on Amazon. Not Amazon. eBay for $60. Still so pricey. Yeah, but it's really cool. Yeah, it looks nice. Looks really nice. It's not nice, like neon blue. So yeah. And it's bright. Yes. Very bright. That's why I picked it because it has a crazy viewing angle. And it's really bright. You can see it when like, like all the sun's are shining on it. All of our Sun's all the suns what you don't live on tattooing.
We will discuss that in a couple. Sometimes Houston feels like
Nabil Arizona. Yeah,
it's a little too wet. Yeah, too wet here.
Every tattooing during the wet season, if there was one. Sure. Okay. So the only thing I need to figure out on on this thing now, at least on the cabin board is how I'm gonna do the switch IO. How I want to read those in and wire those up, because I still haven't really, there's a lot of different ideas I have on it. And there's some trade offs. So probably by the time I figured that out, like and probably next podcast, I'll probably have a why I do. I'll tell you how I did it. And what were the other options and why I did this way, and pros and cons and stuff like that. So because I haven't explored all of them yet. But the in the switches I'm using, I found some very inexpensive toggle switches that you can buy in bulk on Amazon that have an illuminated like LED on the end. And they're really cool. Because that led the ground pin for the LED is exposed on the back of the toggle switch. So I can I'm going to hook all those up into A into A into a FET on the board and so I can toggle them and so that I can use the dome lights inside the Jeep because it's variable. So you can like adjust it on the dash. Oh, you're going to have it go with it. Yeah, so that way you don't like if you have the dome lights dim. These aren't like new cooler red shining.
Just going to PWM Yeah,
PWM it with a with a that. Cool? So now the only thing I haven't figured out about that yet is like because if I'm using the 14 volts is I had to figure out I'm probably have to use a BJT to drive the gates because the prop is only 3.3 volts. Oh, the low side. Yeah, so I can't really, you know, I can't pull that pin up to 14 volts without blowing up the propeller. So if these BJT
or you can just do a fepto FET. Same thing. Yeah.
BJT seem to work better for that though. Sure. Back. Can you use it though? Cheaper either way works either way works. Yeah, that's effective. Yeah. It's kind of a voltage.
What do they call that? A they call it a DC shift transistor. Like I think I think it's funny. I absolutely hate it when people do this. But sometimes it works. But Like the the when you use a transistor and a specific configuration, people give that configuration a name. Yeah. Like a DC level shift transistor. What that ends up sounds like is it sounds like the transistor is something really specific? And like, Oh, I'd have to buy a really specific transit. No, it's just a configuration. It's just the way that you plug. And for new gamers, man that is hard to learn. Yeah, I That's annoying.
Well, even just how different modes of transistors transistors in general are hard to learn. Like, also weird. Yeah, well, you have linear, you have nonlinear, you have saturation mode. So yeah, and
then and then you get into FETs. And you have your PNN, you have depletion and enhancement mode for each PNN. Yep. And those are those sort of work opposite to BJTs. And then you have J FETs, which sort of work opposite to that.
And you think about in your, you're forgetting about avalanche mode. I mean, that's it, that's what it's called. And it's only happens for a short period of time when you transition. But it's like, it's something you have to think about sometimes when you're designing high end motor controllers and stuff,
right? And then and then you have to ask the question, like, should I get a small signal? MOSFET? Or should I get a power MOSFET? For this situation? Most of the time, that's an easy thing. But it's not always
well, it's not always, as you say, it's not always because if you're doing if you're doing a motor controller, that's a really high speed. And you want, you know, usually you have to have the FETs controlled by a microcontroller. And so you would say that's, you know, small signal, you want to level of level gate level, that threshold threshold, you know, V G S VGS, you want that to be really low. The problem with that is your gate most time on those, the gate capacitance is ginormous, right? So when more things slows down your gate switching speed, it most of the time, it depends on how hard your microcontroller can drive that pin. And so if you're doing it that way, then it's like, okay, now you need like, an amplifier, off your off your pin to hammer that gate as hard as it can to turn it on. And it's like, okay, at that point, you can just use a power MOSFET. And then the BJT or smaller FET. That's got smaller gate capacitance to turn it on. Right? Law trade offs. Yeah, it's also the thing about,
and then half the time that amplifier that you're doing itself is a transistor, yes, you have to worry about this. And it starts to flip your logic, and then everything gets really nasty really fast. So yeah,
I wonder if there's going to be like, I'm not sure there are dedicated I bet. Like when you buy a dedicated Micucci, like, motor controller, it has, like, super powerful outputs on whatever the controller is. So bypasses that step. Probably wouldn't make sense. Like it's try states can pump out juice.
Make sense? Yeah. Usually, you want something that has some, excuse me some output capacity capacity on your, on your tray stage. I mean, you don't want it to be like, super weak or anything.
Well, most microcontrollers are like in the 20 milliamps, which should be enough to drive a fat, but you'll still get some slew.
You know, okay, so that's another interesting topic, most microcontrollers have up to 20 milliamp capacity. And that's sort of like screaming hot if you're doing full 20. But most microcontrollers have a total consumption maximum of 200. And you, it's not hard to get to 200 milliamps. You know, especially, let's say if you have a whole port, so a bank of eight pins on a microcontroller, and you hammer eight LEDs all at once, yeah, you've eaten 160 milliamps just glue a
penny on top of it.
That could be the title of this podcast, glue a penny on it.
That would be crazy. Like if we, we get a order here at macro fab. And one of the steps in assembly is glue me on top of the my controller or FETs.
You know, and one thing I have absolutely learned here is just wouldn't surprise me. It wouldn't.
Oh, cool. So Steven, you have something really cool to share now.
Well, so yes. Oh, you think it's cool? Of course. It's cool. Well, okay. So actually, let me let me let me shoehorn this in really quick on top of that, because I just remembered it. So yesterday was sort of the last day at the science museum for me. So our projects are like, done done. I will have to go back some time eventually to do yet. Well, no. I think I'm going to get paid. If I go back. Let's put it that way. I've been there so many times now. So but they needed on one of the projects. There's a there's a video screen that plays an animation while my project moves. In fact, it's the one that we posted a gift to and they have an engineer there that is setting all of that up. And the funny thing was like I had always known that they were going to do that And I had offered to help them with that such situation. But their engineer went through the whole process of like studying my design without a schematic or without the code. He was like doing logic probes and all kinds of stuff on my on my, my box that I built to figure out like he was sniffing the lines and like what happens when things happen, and he built an Arduino circuit around my box that does all this craziness in order to trigger the device. And and I talked to him last night, it was like, you went through a lot of trouble, you literally could have called me I rewrote two lines in my code, and I pulled a pin low, and then pulled it back high whenever the the cycle was over. And now he's using that. And I was like, why didn't you just call
it probably used to not having that option. And so he just assumed
the guy, the guy probably spent forever on that. And I mean, it's a it's a cool situation. He has an Arduino, Leonardo or whatever. It's it's one of the Arduinos that can simulate a keyboard. Yeah, Leo. Yeah, yeah. So He sniffs my, my logic from my controller. And when he senses that things are moving, then he has that simulated keyboard and basically press spacebar on a computer, and it activates the animation. So it's a it's a hack, but it works. And it's, but the problem with it was it since it just presses the spacebar, and he didn't, he didn't have the, the code to determine when the cycle was over, you could just keep re triggering it by pressing the button on the kiosk. So that's why I was like I'm pulling a pin low for you. And it'll go high when you can retrieve
this. The thing is, if you weren't known that, from the start, you could have used a microcontroller to just simulate a keyboard on a port. And so you wouldn't have to have that board.
Right. And and a lot of these things were not predefined. Yes, a lot of them weren't designed until recently. But But I thought that was I feel kind of bad. Like, I've totally probed other people's circuits and like figured their circuits out. But when someone does it to yours, you're like, Man, I feel bad. Like you had to go and do all that work. And you could have just called me, you know, whatever. Oh, you
felt bad for a different way. Yeah, I guess. Yeah. You didn't feel like violated that. He did that? Oh,
I don't I don't care if he sees my circuit. Whatever, dude. Yeah, he did. He did. He did. Like, as with any engineer, he's like, What the hell were you doing? You know, like, that kind of stuff. But he was also like, I've never seen these, this PLC before. And he was like, super intrigued about it. He thought it was cool. I used that plc.us thing. Yeah, there. So he thought he thought it was neat. And, you know, he's got, he's got an Arduino slapped on top of it to control all the screens. Hey, pretty cool. Okay, so back to back to the original topic, dip trace, released a new update this week, or a couple days ago. Yay, version, version 3.2. And it is a very, very simple update. But I was like, every time I see an update
for Vic's bug in help file
you know, it's surprisingly like that's that we get a lot of that. Did traitors get get a whole bunch of that? And and I have I printed off their whole change log for version 3.20. That's what that's due to paperwork. Yeah, yeah. And I'm not going to go through all of it. Because most of it is super boring. And most of it's just like, whatever it applies in like, point 1% of all situations. But here's it. Here's one that I'm actually super excited about. And we've been asking for it on the forums and stuff for a while. You can now rotate and flip by groups. When you are making patterns. And welcome to
the 21st century. No,
I know like there's some things about diff tracer. I'm like, Well, I was like, if you if you drew your whole footprint in the footprint editor, if you drew it vertically, and you now for some whatever reason wanted to make it horizontal. There was no way
because you want to make it like I IPC certified. Yeah,
exactly. There previously, there was no way to select all and rotate, you would literally have to go and change every single pad.
Oh, didn't have any Cardinal rotation.
Yeah, no, they they had none of that. And, in fact, okay, so the remember the synthesizer. With the I was going to do all the LEDs around the floor, I still want to do that. That'll happen eventually. Instead of placing, okay, so there's I can't remember how many LEDs it was, it was like 500 LEDs that were going to go on the board. What I wanted to do was I wanted to make a footprint in dip trace that had all the LEDs in their proper location will without the Rotate Group command. I would have had to replace all 500 LEDs individually on a circle and that just screwed things up. So I'm kind of done because now I can do it. Yep. So yay whoo There we go.
Yeah. You have something on here about Chinese solder woes okay. What is that about?
This is this is a fun one so that that project I'm working on for the the art piece that my buddy and I are putting up in the contemporary art museum coming up here soon.
Oh is the other art product
the other art project yes this is the one with the the falling rod falling rods Yeah, which by the way we tested it the other night we did a full run with all the rods. It's awesome. Yeah, it's totally awesome. Yeah, like I had it so I have it so it writes a complete random array to memory and then it reads that back and drops those random locations and I had it where they was dropping rods every three seconds and and it was just it was just awesome. It was like it was like giant pickup sticks super cool super cool. And it worked like a dream so yeah, so
when I was your wife gotten back her table yet
i Yes. My coffee table was a four by eight sheet of plywood with a bunch of solder on top of it for a while she is she's my wife is a trooper and I love her to death because she puts up with my random stuff all
the best is when you go into his apartment there's there's a tire in there too. That is moved
that she forced you to move no I made the decision myself myself on that. Yeah. It hasn't gone away it's just moved. It's in a closet now.
Yes, it is better.
Yeah, and it's got brewing gear on top of it go figure Yeah, go figure. Yeah. One of these days. I just want to get the rim off of it. That's all I want. Yeah, because I'm driving without that rim right now. Yeah, whatever. Okay, so back to this on that project I had a bunch of soldering to do on these plates because I had the whole array and I designed all these boards to solder to and I picked up a I actually ran out of some some solder some good lead solder and so I found a spool here at macro fab that was floating around it actually been floating around for a while and I think we got it I can't remember where we got it from it was some like we got something
was it that cheap soldering kit I bought yes, there's a $6 soldering kit up I think
that's what it was from and I was I was so I was at the fab the other day and I was like I need solder and I need lead solder because I'm not going to solder with his lead free crap. And and I found that spool and I was like okay, I'm gonna take this home and just use this because nobody's gonna want this I gave
it to you it was sitting on your your bench over there. Okay, on that bench.
My shell show all my my broken crap on ya know,
their projects in progress. A bunch of pips
bunch of pet projects in progress. I like that, like, well then I need to get the synth off because the synth is sort
of done. When we get all the LEDs add to it now.
Ah, put it on the shelf. So, so yeah, I take this, this solder home and I start soldering with it. And I'm like, What the hell is this stuff? Because it just doesn't work. It doesn't. It barely melts. It gets all goopy. It looks like a really really bad weld job. It doesn't make any smoke when you put it on the iron it just kind of like globs, it didn't have flux in it. Exactly. Solid core. It was solid solder would no flux in it at all. So it doesn't stick to anything. No. And so I would if you fluxed it? Yes. Yeah. Well, yeah, I know. And the reason I say no is because the next day, I actually grabbed I have a whole jar of Ra flux here. And I brought that home because I was like, well, I'll just fix this with RA flux because ra flux fixes everything. Yes, yeah. No, it doesn't. I don't know what the alloy of this crap is. It is horrible. It doesn't solder it doesn't stick to anything. Literally. I would solder a huge pad and I on my board. I have a pad that is like an inch long by half an inch high. And it's just a solid rectangle of copper. Like you you that's the easiest thing to solder to like you just put heat to it and slam solder into it and it'll stick. No, I would I would solder this thing I'd put massive globs of solder on it and let it flow and then pull my iron away and the whole thing would just fall off so yeah,
I want to stuff is horrible. I wonder if it's not lead. I want to share so it says PV on it.
It does. It does say lead on it also it does say Chinese solder like literally Yeah, it's the worst stuff on Earth. I mean, I went to Home Depot and bought Home Depot solder because it was close to my house and Home Depot solder is better than that. And that's
pretty bad. Because you didn't you Get plumbing solder.
Oh god no, no, the just like with the like the threaded fittings at Home Depot. They've made solder really easy like you go and you buy the one that says electrical on the front. You don't have to know what it is it just says electrical.
So yeah, you get it. I was lead free though.
Nope. Hey, I looked at the package says lead.
Hmm, yeah, I wonder what the alloy content is? Is 6040
a 99% lead and 1% Flux. The best stuff on earth
that's braising stuff.
Yeah, so watch out because not all solders are the same. And some solders are basically not solder.
We can talk about that. Yeah, yeah. Let's talk a little more solder. Okay, so I think we've talked about solder before but we can do it again. So if we have it was a long time ago. So my favorite solder is I have a whole one when my grandfather passed away I went to go and we you know, went through all this stuff, and I found a box of solder. And literally a box of solder. It's like 20 pounds of solder. It's all bunch of Kester, for for from like probably the 60s 70s all in cardboard box one pound spools and there's like 20 spools of it nice. So I gave one to was not the one that you ran out of. No, no.
I have that one. It's just not at my house. Yeah,
so it's 6040 with RA flux, and that stuff will solder anything of that
is that is absolutely without a shadow of a doubt that is one of the best solders it's not the best
I've used but it's I have so much of it it's like my go to solder at home now. It is really good everything I solder on the Jeep is what that stuff
I had a and it's a good it's a good diameter jets it's it's
um go look.
Oh okay, he's got a secret a secret drawer with solder. Yeah, there we go. It's even in the old like square box.
Yeah. This stuff is does not have a diameter on it.
That's got to have a diameter meet
it is. It's Kester for for resin core solder to eight one resin core. Ah, point oh, it's 31 mil. Yeah. Which is pretty standard. Yeah. That stuff is awesome. It's not the best I've used. And that's the 6041 I've used a 6337 Yeah, by N G chemicals, which is that big company that makes a lot of chemicals. Yeah. It's a company that makes like your like that your flux sprays not flux by the contact cleaner cleaner with the new Yeah. Yeah, you have like a whole episode you talked about that.
Because it's all
they they make a really good 6337 I've used that has RF flux. And for some reason that extra little bit of lead makes such a huge difference.
Really? Yeah. So So I'm the 6040 Man, I like the 6040
Well, that's what you can get now it's really hard to get that 63 737 now and it's expensive to Yes, that's why when I found this whole box, my dad was like oh, we're gonna throw it away. I'm like no, my that's a couple $100
for this so here's a question for you. When do you use that this might be simple but when you use really thin solder when do you use medium solder and when to use really thick solder
water the size of what I'm what? Soldering so the smallest I like to go is this Oh 31 Even with like big stuff may I picked up a small stuff because I tend to use like big chisel tips to solder stuff like even like TQ FP which has a point four millimeter pitch. I will solder with a chisel tip that's like just a monster that's like two millimeters wide and I will do is I'll turn the the iron sideways and use just a corner tip and then drag solder with that. Gotcha and so I'm not at that size I don't really need really find stuff now I do like big stuff for big stuff like for doing trailer wiring. When I get out my like 250 watt soldering iron with the gun the gun. Yeah. And then I'll have like, you know, it's almost like quarter inch diameter. Wire. Yeah, yeah. So So that's it. Oh, 31 is about the small cell go.
Okay, okay.
I never used really any finer. We have some really find stuff here. And it's like angel hair. You know? It's like, oh, so it's like, oh, one so I'm like, no, that sounds way too small.
Yeah, that's that's 20,000 or something like that. It's really thin stuff. That stuff is really in for most applications, so it was really annoying. It's 20 Yeah. 20 though
Yeah, it's actually this is actually actually thicker that we have here we have something that's actually smaller than this. I think we have a one sniper solder sniper solder.
If you're if you're if you're soldering like oh four Oh twos all day long then sniper solder is okay.
It's when you have a pencil and paste. Well, yeah.
Okay. Soldering really tiny stuff or reworking, I guess. reworking Yes, reworking wood. So it's it's a giant pain in the ass when you have solder? That's way too big. Yes. And it's also a pain in the ass when it's way too small. So there's always a window that works and oh, 31 like the tester that you have. That works really well. For most applications.
I think we have this. I think we have like point o one. And then we have point O two. And then we have point oh, three, two? Yep. And then we have point oh, six, four. I think we have a size bigger than that here.
64 was like, but splicing wires, you know?
Yeah. Now we've got some bigger stuff. That's pretty chunky stuff. Things over on this area. It's like looking around.
But but when it gets to that kind of stuff, you almost need a big iron, just to make sure that it flows, you know?
Yeah. 62 is the biggest we have here.
Okay. And the big the biggest problem about big solder well, okay, so with small powder, if you need more, you just keep feeding it. But the big thing that's annoying with thick solder is that once it flows, a lot of it starts to flow. And then you get, you know, bulbous joints.
Well, the thing about the reason why you want to use big solder for big joints, is because the bigger solder has more flux in the core. Yeah, per volume, right? And so in need that extra flux, where if you're feeling a little, tiny, thin solder into the joint, you won't get enough flux in there. You'll get more solder. And you you're actually what you just said you'd have more bulbous, you actually get that with the bigger stuff? Because you don't have enough flux to float. Right? Well, you
mean with the small stuff? Yes. Right. But it but it all depends on what the what the joint you're working on, is if you have a if you have a medium sized joint, and you just need to feed more thin stuff that works. If you have a giant joint and you keep feeding thin stuff, it just kind of like drops. Yeah, it just kind of like, you know, comes off the joint effect doesn't stick. Yeah.
Because you don't know flux in it. Right. So speaking of flux, of what's your favorite flux and how to use it, like application wise, and bottle. I have my own way too. So So I
once again, like solder flux is dependent upon what the situation calls for. If it's a big joint, I'll get a Q tip and RA flux, and I'll just smear it on and go to town. And that's more like if I'm doing something where the solder has a mechanical aspect to it. I'll do ra flux. And and just kind of smear it on or I'll use an acid brush. Okay, something like that. Because you got you got either a brush or a Q tip line around somewhere. Now when it comes to like the fine stuff, an applicator needle in a squeezy bottle, yeah, that's where it's
at. Yeah, cuz I used to be I like flux pins, until we started macro fab. And we then we had flux in bulk, basically gallon jugs of flux. And so then I got the applicator bottle like this is so much better. It's not because you can get applicator balls that have the felt tip, but just the needle tip is the best I think, because you can just like squirt it like it doesn't wear out.
It doesn't wear out, but you can put as little or as much as you need. And that's the biggest with with soldering. That's the biggest thing. Yeah. as little or as much as you need. Yeah.
So you like RA for an applicator bottle. So what do you like, like water based?
What water based tends to stay on the board longer. You have more time to work it. But it's it's really greasy. Yeah, it is. And that's the part that sucks. Yeah,
they clean it really well. Yeah. Well, you have to clean. That's the thing. Right? Right. If you don't it'll all right. Yeah. All right. Yeah. Oh, just eat it up. Yeah, eat the copper up and leave green fuzzy stuff all over the board. Yeah. The ra flux, generally you can leave it. It depends. Well, that's how aggressive the RA flux is.
Yeah, so I work. Obviously, we've talked about 1000 times but I've worked with a lot of old equipment that has a lot of old ra flux on it. And it goes through stages of like, it starts off like earwax, and then it turns into like a crystalline structure and then it goes to like granite. It gets nasty with age.
So from when I do like trailer wiring, or if I do any kind of automotive wiring, that's old, because what's hot wire happens when you make a quick because all automotive stuff is usually crimped. And with OEM stuff they don't really care if it's sealed or not so they don't use like they don't use a sleeve loom lot Oh yeah, they just which is a heat shrink that's got adhesive lining so when you heat it up it actually seals the joint so they don't do that so you what you get is moisture in gray ingression into your inside your insulation on your wire. And so you'll like let's say the connectors messed up so you cut the connector off and the you cut like you know, mostly your connector repair kits have like 12 inches of wire that come off of it and so you cut 12 inches off your harness and then you ship the wire and the copper is black because all the water ingression has gone into your cable and corroded your entire wire yeah and so now you got and you cannot you cannot solder to that stuff. No you know and normal flux won't do anything with it so I have actually a bottle of plumbers flux acid cool acid No, this is a bottle of what's in acid core. It's it's plumbers acid, uric acid acid you use you dip it in that for a little bit and then wipe it off and then that will get the oxidation off of it and then you can put it up and use our a flux like normal,
right right. Because Because and stranded wire is really notorious for that cause capillary action Yeah, it sucks the water up and it just keeps going keeps going it's sort of doesn't it no
it doesn't and it's one of those things like that's how cars in the future will die.
Oh yeah all the copper just all the copper
will be eaten away and you know you'll never be able to get new wiring harness so it's not like well, it's it's either that or the plastics will just deteriorate to nothing in a couple million. Well, no, just get brittle and fall apart.
Oh, yeah,
I actually fight that in my jeep because the 90s jeep and plastics American domestic vehicles plastic sucked in the 90s. So like whenever I find a chance with someone's like, I made a x out of metal. I'm like, give me one. So I can replace the plastic part with a metal part.
Because it's just a new car just keeps getting heavier. Yeah, just gonna get heavier.
I think I actually probably does weigh over 4000 pounds now. Oh, yeah. The Oh yeah. The kerf weight was 3700 brand new a but I've added a hardtop. I've added a beefed up rollcage armor and bedliner
I've helped you lift most of that weighs over 4000 All right. So that was solder and flux.
Yes. Oh, so speaking of plumbers flux or or acid core plumbers ass crack Yeah. Don't use that the solder electronics.
Oh, yeah. No, it'll eat right through Yeah, like
it will eat through it in like a couple hours.
Yeah, yeah. That's That's why and Home Depot. They have on the boxes as electrical. They try to dumb it down as much as possible. So for
this guy we talked about let it though. Lead Free stuff.
I know. I've what's the point? We don't need to talk about that.
Well, so MACRA we use we use Sackville five for s&t as in the paste and wire. So we have to do any kind of touch up work on SMT. Its Secretary five, because you don't want to mix alloys. Hmm. But for through hole we do sn 100 or sn 99, which is essentially 100% 10. Yep. Yeah. Which is that's because that's what's our what's our selective solder it that's what it came with. And so we've kind of like, well, we got 35 pounds of salt of sn 100. I guess we're going sm 100 for all through whole.
And I actually, a couple months ago, I took a sample from the selective solder and send it off to a lab completely forgot to talk about that. Yep. That was back when I was playing quality games. So I was I was checking things.
Yeah. We set off on a soldering tip and stuff like that, too.
Yeah. Yeah, we sent off a soldering tip and they they carved through the soldering tip. And they did some, I don't know. Electron Microscope thingies. spectrogram. Yeah, whatever. They found out what the the makeup was. And the whole point is just, we knew we weren't lead free. But if somebody asked us we wanted proof that we were lead free. So I sent it off to a shop and we were lead free, but it gave us a breakdown of all the crap that's in ours. Selective solder powder. Yeah, actually, it was a lot cleaner than I ever thought it would be, you know for how it looks. It's really clean. Yeah, basically it's tin Andros and dross is just oxidize oxide wrapped in basically it will oxidize anything. So when you Do that's the thing was when you do
like wave soldering and stuff, it actually will like, because we have an E NYG. Which is electroplated electroless nickel intellectualist actually yeah. But has a gold finished base gold flashing on on the pads and actually will rip some that gold off. Oh in for wave soldering wave solder and selective it will actually rip some that go off and so you get gold or whatever your surface finishes into your pot. And that's actually one of the big reasons why you have to eventually swap it out is that level sources build up? And then it started sticking it's up soldering.
Yeah, yeah, well, and something do that is worth noting is like that you put, we always check, we make sure that things are lead free, but at the same time you got this big pot of molten lead, it's spraying up onto a board. And sometimes it drips back down. What if one of those components, maybe had some lead on it, it could drip back down and contaminate your pot. So it's worth checking, even though like the chance of it happening is incredibly slim. You know,
but it had no lead in it.
So it Yeah, yeah, the lead content was nothing, and neither did our soldering tips. Yeah. So we knew that but you know, if somebody were to ever audit and say, Hey, we can say we're sure, yeah, we
got documents that say otherwise. Yep. Cool. So we can go on RFO real quick. Let's do these as we've been artists for almost an hour now. Right? Ah, four minutes to an hour. All right. So let's do each RFO in two minutes. Okay, go go. The Amazing $1 microcontrollers. This was
I like it done.
J Carlson has a website called J Carlson dotnet. Go figure. He did a comparison between 21 Different microcontrollers that are all under $1 All different manufacturers and also did their tools they have what peripherals how fast they are. All this stuff, like set up, blink, all that stuff. And yeah, really cool. It's Jay Carlson dotnet, slash microcontrollers. Did
he like rank them? Yeah. Okay. So there is a number one. Well,
he didn't rank him as number one, but he's like, this one's really good. Yeah, mate was was tough.
I thought it might be I thought it might be.
Yeah, really cool. His website is really like web 2.0 He,
uh, yeah. So I always have your words. Oh, tiles and parallax.
Like yeah, like you when you scroll down. Like the graphs like you scroll down. And then you get to the graph of like, speed and then like, each individual bar, like goes out to what the speed is. And so
yeah, it's real snazzy little snazzy. Cool.
cortical. Give it a read Steven.
i You will have to
now okay. That's two minutes, right. Just under actually cool. Okay. So topic two is Alibaba buys into CPU company to support Ali. Oh, s. Oh, no. This is this morning, just like when Amazon came out with AWS. Which the Amazon Web Service? Yep. Basically, Alibaba bought a stake in a Chinese microprocessor manufacturer. To promote the development of processors which support Ali O S, I had no idea what Elio was. Is we there's a Oh, s for Alibaba. Yeah. Amazon's got one. Really? Yeah, that's what their tablets and crap run. Hmm. And the Amazon fire runs its own
as well. Would that make sense? But why does Alibaba need
one because they're gonna be the Chinese Amazon? Oh, yeah. Oh, yeah.
Well, they're kind of the Chinese Craigslist right now. So they need to step up their game.
But no, because it comes this is what made me think of Amazon Web Service is they have a alio s, they have a cloud computing option, which is what AWS is cloud computing. Okay. So yeah, and they have an ollie Oh, s things for IoT, which is f what things of Internet of Things, but okay.
I think it's interesting, more competition. The only problem is where the servers will be located at if they're located in China, then you have the Chinese government to really worry about I mean, I guess you have to worry about here. You know, the NSA will get no like tin hat right now, but I'm getting the foil out. Yeah, get the foil out. Because like technically, like the NSA can go into AWS since audit crap. But over there, the Chinese government can just go hey, we really like that thing that's running on the server. So we're just gonna take it for ourselves.
So I'm, I'm interested. Yes. Usually what
happens? Any I put sway any competition to because right now, AWS is really the only big thing there's a couple other people out there trying to do it, but they're like The big guys, the big juggernaut basically in cloud computing. And so if anyone comes up, I think, if anyone could be it'd be Alibaba to, you know, be a decent competitor.
It's interesting. And and getting into the microprocessor game. Well,
I think, yeah, it's probably building microcontroller a micro processors for like tablets and stuff that can run their iOS. Yeah, probably implementing a, a very, it's like, it's like the Apple. Apple, basically, custom makes their own CPUs for inside their iPhones. So that they run faster, supposedly. Okay, probably similar
thing, but you don't ever buy one tablet you buy 10,000 a month. And they're they're five cents apiece. Yeah. And DHL shipping is free at free, right. There we go.
That shows up in a box all taped all the yellow box data more tape than actual box out your box. Yeah, it smells like burnt tires.
Welcome to ollie.
We've ordered some more stuff on
you. Oh my gosh. Yeah. And it's always the same. Yeah.
The best was when? Yeah, when? Because Because engineering is here in the warehousing at that macro fab. And so when like new shipments come in, you can definitely tell where they came from. Just from the smell.
Oh, yeah. Yeah. And they have that really distinctive. Clear yellow tape. That's all over the box. Yeah. I mean, they make the tape has to be cheaper than the box. Yep. Yeah. Actually, one of our guys out on the floor showed me something he bought today. I can't remember where it was from. He was like, I whatever. But he paid $1 for it. And it was a USB power monitor that you plug in.
Oh shit. It was only an adult. He plugged that into my computer. It was a buck.
It was $1 shipped from China $1
Geez, I'm more worried about what that infecting my computer with?
Yeah, I mean, he showed it to me today and he was like $1 It's like uh, I don't know if I trust that so
we should open it up and look at the solder quality
oh, let's go it's got to be well the way he explained it to me is is the product I guess failed and they're just trying to get rid of them Hmm But at $1 apiece shipped
actually let's let's ask Ramon is one who got it that's awesome moon on where he got from it's we'll order one and then do a build breakdown on it.
It's like wish calm or something like that. I can't remember what it is
sound sketch a total scam. I use a PayPal account to pay but
hey, it worked. That's the thing but it probably infected your computer probably. Yeah. You know have Ali OH S Yeah.
Ali HIV
Oh, that or
the hep hep alley? The sound goes wild. Yeah. Okay. finish this up. Okay. That was the maximum engineering podcast we're your hosts Pablo and Steven Craig. See you later guys. Hey, good
evening Thank you. Yes, you our listener for downloading our show. If you have a cool idea, project or topic that you want Steven tonight to discuss, tweet us at macro lab or email us at podcast at back fed calm. Also check out our Slack channel. If you're not subscribed to the podcast yet, click that subscribe button. That way you get the latest map episode right when it releases and please review us on iTunes. It helps the show stay visible and helps new listeners find us and that was the first time I did it without adding anything except this end part.
The quest for the right connector for a project! The right of passage for any hardware electrical engineer starts with a connector catalog.
The Jeep Prop Fan project rides again! Well some iteration of it at least. Lets design an open source PCM (Power Control Module) for automotive apps!
This is the last installment of Stephen's 'Adventures in Injection Molding'. We are going to recap the entire two year sage and close the book on it.