On this episode, Parker and Stephen talk about if the Arduino platform is right for students learning engineering.
Podcast Transcript
Host 3
Hello and welcome to the macro fab engineering podcast where your host, Stephen Craig
Host 2
and Parker Dolman. This is episode 37. Number 37.
Host 3
Host 2
A? quite a bit actually at Mac fab, we're gearing up for the move will be moving at the end of this month, October, right last Friday is move day right before Halloween. So we've basically been getting rid of stuff that we haven't used in a long time. Pack starting to pack stuff up, organize stuff for the movers. It's getting pretty crazy. purging all the trash. Yeah, yeah, getting rid of everything. We're actually starting to chop up all our old shipping crates, because we have like, basically like the entire like, on ramp that the movers are going to use is filled with shipping crates, we got to chop all that stuff up and throw it in dumpster. So that's all next week. Yep. I was working on last week a fixture for the selective solder to hold up big panel right and prevent it from basically sagging under its own weight. And basically like messing up the Z height on the machine, because it doesn't have a laser. So like when the nozzles underneath it, it doesn't know that the board is sagging down. Like the the my 500 which is the pace jeder. And then my 200 have actually optical laser measuring. And so they can actually know if the board is slightly warped. With select solder it doesn't. So you kind of have to make sure the board is completely level. I guess that's actually a better solution than this jig is to add, like optical leveling. Just like to solder.
Host 3
That would be a pain. Be cool. It'd be super lasers received. But yeah, well, because the selective solder is a bottom feed. Yeah, it's a bottom feed, you have to have the entire panel open.
Host 2
On the bottom. Yeah. So you have to suspend it from the top. And so my solution is basically a big open aluminum frame that the panel sits in. And then they arch support that goes over it with a magnets that you basically put underneath the bottom. And it sucks it to the arch.
Host 3
Right? Yeah, because it's 16 inches of Fr four that has random cutouts and all kinds of V score a mean guaranteed that it's going to be stiff in any direction.
Host 2
So yeah, that's what you know that that fixture is designed. It's actually most of its put together now. So I'm actually going to start testing it next week. Awesome. Make sure that you know that the magnet actually holds all the parts because it's only about 11 pounds of holding force. So it might not be enough. That should be enough. And then, in the same vein, I've been working on the OB, which is the optical alignment test board.
Unknown Speaker
Host 2
Yeah. So what is that? So we talked about this earlier, a couple podcasts ago, basically is a giant 16 by 16 panel that's got measurements in metric and imperial because we actually since we're American company, we have to deal with Imperial lots. But our machines are Swedish. So they're metric. I think the Swedish micronic is Swedish Yeah, I think so. Yeah. Yeah. Swedish engineering precision not a watch so yeah, so basically it's a four alignment of camera systems so that when we finally start getting to the same machine the the software end of that we can actually test to make sure our software is working well
Host 3
right right so it's a full 16 by 16 panel with all kinds of packages and Marky Mark easels yeah it's got everything it's gonna need to look at
Host 2
Yeah, it's got through hole plated through hole non plated through hole trace with a different you know, thicknesses it's actually a a it's actually a panel to to also test to see how well jet reproduces jets are PCB manufacturer, how well they reproduce this giant panel. So it's gonna have silkscreen and all that
Host 3
stuff. Yeah. Yeah. I mean, that's a lot of real estate to play with. Yeah, especially if you use both sides.
Host 2
I'm not sure when to use one side. Okay, so gotta have the other side. All copper to increase rigidity. Ah, okay. Yeah, it's gonna be a stiff heavy board. Yeah, it's gonna weigh a lot. Yeah. So there's that. And then I've been working on the fantastic air real time tester. I'll let y'all figure out what that means. I'm using a at a fruit light tower. Yeah. So light tower is basically a it's, it's similar to what we have on our machines. It's a basically a a, an indicator light that has red, yellow and and green on it. And depending on the air quality that this thing's measuring, it'll light up different colors. And I've been looking at, I'm gonna probably use the macro Duino. Yeah. And then build a shield that plugs in. It'll use the I'm thinking about using the IA Q No, I yeah, I AQ core was What's that chip, which is a air quality for voc measurements. Oh, okay. And they'll have like a light sensor and that kind of stuff
Host 3
is, is it digital? Or does it spit out like a voltage AC? I squared C. So it gives you some kind of reading of quality level?
Unknown Speaker
Yeah, it has a best guess of Voc quality.
Host 3
What like, what is it actually give you like zero to 100%? Or like that? No,
Unknown Speaker
Host 3
Oh, okay. Okay. ppm of bad stuff.
Host 2
Yeah. And it also measures co2, I think. Yes, it does measure co2. Problem is this part $35. I found some cheaper parts. Cambridge, Cambridge, CMOs, sensors, CCS, they have a cut part called the 811, which is actually we talked about that sensor on two or three podcasts go when the Silicon Labs came out with their thunder board. This part is on the thunder board, right. And the fact that the thunder boards $30 means that chip is less than $30.
Host 3
Or they're subsidizing the snot out of it. Maybe but
Host 2
that's a that's a huge sea bass and chips free, right. Actually might be worth to buy thunder boards and D solder that part and put it on board.
Host 3
Yeah, so it seems like this air quality thing Parker brought in a package into the into the podcast today. What is it? It's a air filter.
Host 2
It's an inline air filter for like, cars and stuff. Yeah. You
Host 3
just got the package today. Today? Yeah,
Host 2
yeah, it's made out of carbon fiber and stuff. Open it up. And that the resin in that thing is just like VOCs everywhere. It's just terrible.
Host 3
It smells like gasoline and paint mixed in. Yeah. So that sensor would be going nuts. Yes. 65535.
Host 2
Yep. So yeah, that's, that's projects I've been working on.
Host 3
Cool. So last week, I talked a little bit about the 8098 33, which is a function generator, I see. It's about 10 bucks. So it's not really that cheap. But I was talking about using that in a in a little synth project I've been working on. And I was able to throw it all together. And it is killer. This thing is absolutely awesome. So So I use them a lot. It's
Host 2
so awesome. That our scope can't figure out if it's bad or not. We got cheap scope.
Host 3
It's an okay scope. But it's
Unknown Speaker
it's an Oh, when it works. It works. Well. Okay,
Host 3
so for most of my testing, I'm using an old Techtronic. Green Screen scope. Yeah. So it has it has like time cursors Yeah, but in terms of measuring frequency. Anything, I did it all by ear, because my ears, my ears better than measuring the time frequency on my scope. I just had YouTube play like, here's 440 hertz, and I tuned my my frequency oscillator until there. Yeah, and actually, this thing has pretty great tuning and tracking. So it accepts a zero to five volt signal. Zero being 13.75 hertz, and five volts being 1000 or 14,080 Hertz. And if you chunk that out into octaves, that's half a volt for every octave. And it's an exponential curve across there. And it actually works really well. So every every 500 millivolts, you add it goes up a volt goes up an octave. And in other words every 41.666 millivolts increases, correct? Of course. So yeah, that actually works really well. So I'm just using basically an Arduino as a master commander controller, but I found a I found an interesting kind of, it's not a bug but it's a caveat with with Arduino feature. Sort of Arduino is great for like, you just cast a variable as a float and it's just like Alright, great. That's the float we can we can deal with this. But the the exponential functions that I was having a calculate. I had it out to like 20 decimal places or something stupid like that. And I Arduino will only do six to seven. It's sort of kind of up in the air. So so in order to tune my my circuit, I wasn't adding offsets. I was literally changing The coefficient of the until it had good tracking, which worked, I needed seven decimal places to have good enough tracking and it worked with seven. The eighth was kind of like, No, I'm not doing this. So it worked. I need to throw together a schematic because I hope to make like a small PCB that just like, you know, the the the small Arduinos that are just like a breakout board. Yeah, I want this to be a breakout board. But it's all a sawtooth generator that you can plug into a breadboard. And you have a sawtooth generator with a half a volt, per octave tracking. Cool. So should be cool. Yeah. Also, I
Host 2
been you've been on the fixture train as well. Yeah, yeah,
Host 3
I've been designing a strip feeder for our my 200. pick and place machine. So basically, we have most of the parts are placed with reels on tape. But a lot of times we have little chunks of tape that are like eight pieces long, or even less yeah, sometimes like five pieces long. And that's not long enough for us to load properly in the machine. Now, we have to hand place them, right. But if we can have a fixture that holds the tape, we can just apply an XY and a pitch offset and the machine will know where it is. And it can go pick up all those places. And most of the reason why we can't do that small is because we have to have some parts that get thrown away basically, by the machine. So I have a little tray that holds all the strips. And you can clamp them in and it can do 812 16 and 24 millimeter strips, you just kind of put it on this tray, screw it down and put it on our tray wagon and bam, there you go. He now have access to any quantity of parts.
Host 2
It goes on the tray wagon is basically world like parts that are in trays.
Host 3
Right, right. So you might have a matrix of Q fn chips or something like that. And they and that goes on the tray wagon, which is super cool. When you when you post a picture
Host 2
of the tray. I think we need to post the video of that thing working. Yeah, yeah, we use it all the time. Yeah, tray right. It's really cool. Because it's like, because the the my the My 200 is a really interesting design for a pick and place. It's not an XY gantry. Right. In the head only moves in one direction, I guess you would call that x. Yeah. And that's it passes over the board area, and the camera area and the tray wagon and all the parts. Yeah. And then the y is actually controlled to where the board is sitting. So the board goes in the y direction moving. So think of that like a a with kind of 3d printer at Prusa style 3d printers like that.
Host 3
I guess the viewpoint would be if you're all over the machine looking down towards the ground. Yep, the head moves in the x. And that borders in the walleye.
Unknown Speaker
Yeah. And so the tray wagon actually moves in the y as well,
Host 3
right. So you can just put a matrix of parts on the tray wagon, and the tray wagon will move in the y such that the head and the X will go and grab apart. Yep. Same with the strip feeder, the strip feeder will hold tape and move the tape basically in the line. Go grab parts. Yep, everything's good.
Host 2
This is interesting design. Yeah, it's really like if you if people out there know what a Prusa 3d printer, how it works. It has a x, which is the head. Yeah. Moving back and forth. And then the print on the bed moves in the Y. Right. The table actually at a table actually moves. Yeah, just interesting. Yeah. Cool. And RFO Yep. So we've had Scott shockcraft on the podcast before rhymes with the started Chicken, chicken detec. Right like the quadcopter controller stuff. Yes. And it looks like he is now working for Adafruit. Awesome, which is really cool. Way to go Scott. Yeah, he had his first article come out over there for the Arduino zero. Like basically like how to use it and how to do the debugging stuff on it. Oh, that's awesome. That's really cool. It's a really well written technical article. Well go check it out. Yeah. Um, another thing is, for some reason, we've gotten this argument on the Eevee blog, IRC channel about notation on pins on on a basically chip but like a chip like a five five timer of different notation a pin definitions, depending on who's making it. What Yeah, so I actually started thinking about this. And I was trying to brainstorm what kind of chips multiple manufacturers make and one is like the sudden for hc 595 Shift Register.
Host 3
Well, all the 74 series Yeah, is made by everyone. Yeah. Oh, wait, I thought the five by five was fixed. I thought everyone made big Basically the same 555 Well, it's
Host 2
all the five have a timer, but it's how they label it in their schematic. I think you were saying
Host 3
they brought the the pin. Oh, no, that would be terrible. Yeah, be terrible. Okay. Okay. So the labeling
Host 2
the labeling of the pins that are slightly different. Oh, yeah. So I started looking at
Host 3
the 595 is notorious for that. Yes. Because so
Host 2
I first started looking up different manufacturers and then I was like, Oh my God, a lot people make this chip. Yeah, there's see 1-234-789-1011 manufacturers that I could find. Yeah,
Host 3
a short Google Search bunch of big guys NXP ti on semi is I don't think Philips national semi. All kinds of guys. Yeah,
Host 2
um, Toshiba SGS Thompson microcontrollers. Who's that? No idea party bought out.
Host 3
But next week, we're gonna come in all of those 11 have merged into one.
Host 2
Like national semi who was bought out by Ti actually, it was really hard to find their datasheet
Host 3
Oh, is the internet getting scrubbed? Oh, yes. Yeah, scrub
Host 2
that thing? Oh, yeah. But yeah, so we get like, huge seven s for like the serial output pin. Okay, that's the pin I was really looking at. Sure.
Host 3
Is it different for most of these guys.
Host 2
There's some similar notation, but a lot more different. There's about four or five different ways to they write it. So like Q seven s is an XPS ti likes Q H prime. For some reason. On semi likes sq. lowercase h. There's it's all over the map. That's why standards. Okay. So we need to make an IC company called standards Inc. Sanitize all the seven, four series, and sanitize all the chips. And be like that XKCD article where there's 14 standards, we need a new standard to standardize everything. Now this 15 standards.
Host 3
So I'm I'm looking at it up right now. Because I'm curious. The 7400 series or the 70 408? See? Yeah. When did that come out? Because I mean, the 7400 has been around forever. I it's got to be 70s. Right.
Unknown Speaker
I don't know. Just before I was born. It has always existed.
Host 3
Yeah, for you. Always. I swear. It's like
Host 2
it's like, the world was black and white before the 50s.
Host 3
Cameras didn't get better. Okay, well, I don't want to waste time on this. I thought Wikipedia had like a super article on the sorry. 400 series. No, but I thought it was like okay, so I thought they came out in the in the 70s. You would think that they would have because here's the thing, all of these people didn't design it themselves. It's just copies after copies after copies. Yeah. So you would think that they would use the same nomenclature.
Host 2
This is gonna be interesting. I'm gonna try this is buy all these chips. Yeah. decap them and see how much different there.
Host 3
Hey, I bet you they just have different manufacturers written in metal on the die.
Host 2
Yeah. I want to see that. Someone out there do that. Because I don't have time to do it. Someone decap son for hc 595.
Host 3
There's gotta be decapping services out there right,
Host 2
either. Yeah, I actually I think seats do do offer some. Yeah, yeah, that's right.
Host 3
I remember seeing that now. Yeah. Although, I mean, what's the if you're going to go through all the trouble if you're setting yourself up to be like a reverse manufacturer of chips. You're not going to pay someone like he's to do to decapping it's more for hobbyists, just hobbies and educational and having fun and stuff. Yeah, yeah. We can always see and see the top of them off.
Host 2
Can you're seeing see how that resolution? Yeah, sort of sort of chain drive.
Host 3
My CNC will do 10 thousandths of an inch. Your CNC is made out of plywood
Host 2
and chain and angle iron with bearings rolling on it.
Host 3
And guess it works. I've got I've got it tuned. Pretty good.
Host 2
The tolerance, Matt depends on the relative humidity in the shop.
Host 3
Well, okay. It's made of MDO. So it's actually fairly stable. It's not estrus, but here's, but here's the thing. I calibrate it, most of the times that I run it, so it's calibrated to the run. Yep. You're absolutely right. If I put it down and come back three months later, it's not calibrated, right. Yeah. Yeah. But you know, we could we could decap them, but, you know, be interesting.
Host 2
chip manufacturers standardized your stuff. Yeah. Yeah. Earlier this week, this guy named Mark Rittman. He, I think this like IOT done, right? So this is not us complaining about IoT. It's just something really cool. Someone took the first person the show, he took the Amazon Echo. I think it's what's called Yeah, it's that like thing you can talk to and it like does stuff for you. Yeah. It has a API calls that you can, you know, write to. And you can, he basically made it so that when he asks it to make him a pot of tea, it turns on his tea kettle. Well, it's cool. Yeah. That's like one of the first things I'm like, Okay. I could see that finally being useful.
Host 3
What just like a voice control command?
Host 2
Well, voice control command that turns on or turns off appliances. I mean, they've had this stuff before, for like, home automation. But it's always been like so proprietary. It's not been like, open like this. I mean, the Amazon Echo is still kind of close, but least you can, like, you can make it connect to something that the Amazon engineers never attended
Host 3
to do. Sure. Yeah. It sounds like it's a fairly decent platform for heck.
Host 2
Yeah, I think so too. Cool. Cool. And then last on the list is, there was a Reddit thread on either the EC subreddit of my university banned Arduino for senior design. Good.
Host 3
Good. I agree. Well, I really,
Host 2
it's, I will say it's good and bad. How so? So the whole point about basically getting the engineering degree is learning how to do everything yourself. Right. So the thing about Arduino is, all the libraries basically hide everything from you. Like digital rights zero. Hi, I guess right? Yeah, yeah. Yeah. Um, basically turn pin zero high. Right. And it's like one of those like, well, what actually is happening under the hood? Import your hands a lot. Yeah. And, but it's also bad because the hardware is fine. The AV Navi 80 Mega 328 P. That's an okay microcontroller. Just program it with normal C and write your own libraries.
Host 3
Sounds like an elitist. But no, no, I actually agree with you on it. I'm just, I'm poking fun. No, I completely agree. Because the the point of things like senior design is to learn the hardware, learn the architecture, and learn how to morph and mold it to do what you need it to do
Host 2
make. Make it so that when you flip that bit, directly, the LED blinks.
Host 3
So I've got I've got a somewhat of a challenge for you. If that if, if using the Arduino Libraries is not acceptable, then should you be forced to do assembly?
Host 2
I think just doing C is fine. So there's so there's that
Host 3
kind of like a threshold in your mind? Yeah, I think, because I really want to know what's going on inside the thing. You programming assembly, then you know what's going on inside that? Yeah.
Host 2
Um, I always think that you should first learn assembly before C for doing hardware design. Yeah. Just because that teaches you that, how basically, how registers and how does memory work? How does that stuff actually work? Is assembly,
Host 3
it gives you an appreciation for all the crap that needs to happen in order to accomplish one line of code. Yep. And it I think, personally, it helps with writing efficient code. Because you, you, you have to write efficient.
Host 2
Well, if you don't write efficient assembly, you'll be writing it forever,
Host 3
basically. Yeah. So to be honest, I think so I think it's alright, to use Arduinos. In this kind of situation, but not for the final product. You can use Arduinos for prototyping up and do proof of concepts. If you need to just slap something together that writes digital blah, blah, blah, and figure out how chip works, or something like that. Great. That gives you that gives you instead of having to etch a board or do whatever and just to figure out how to talk or something like that. Arduino is fantastic for that. But your final design shouldn't necessarily Oh yeah,
Host 2
I can see that. It's, it used the Arduino to figure out that like, make sure your I squared C protocols like how to talk to that chip is correct. And then go write your i square C protocol or IC driver yourself in C.
Host 3
Right. Okay. So if you've never done I squared C or SPI, learn on the Arduino and then take it further. Yep, you know, because if you have to do it from scratch, it's it's not necessarily easy the very first time Yeah, but Arduino will give you the success of just like Oh, I do. Just type wire dot begin transfer or whatever it is, and I squared C just works. Like or it said, like I was actually dealing with SPI the other weekend with the Arduino, which is super easy. But, you know, I didn't have to read the datasheet to see what mode it was I just typed mode zero, it didn't work mode one, it didn't work. Oh two, it started working. I didn't have to know what those modes were. It's just like, I just ran through them until it did work. You know,
Host 2
you could take it even a step further where you could automatically try modes. Until Until.
Host 3
Yeah, that's true. Good. That's kind of gaming the system and
Host 2
if you really want to be prototyping on the easy
Host 3
Yeah, yeah. I don't know. What do you what do you think about it?
Host 2
I like I said earlier, it's um, I think I think for that level, I don't think prototyping with Arduino is okay. Really, I think you should be writing see from the get go. For this stuff. Using the hardware is perfectly settled. I mean, it's a great hardware platform. Yet other hardware stuff that plugs into it. All that stuff is great. Just don't use a don't use the software packages. Rosie our studio?
Host 3
Yeah. AVR studio and in the 328 P is Yeah, that's fine. Yep. So when you when you were in school, was this even an issue? Were there people trying to use our to Windows? Because I don't know remember at all. Anyone doing that? Because
Host 2
I went scrolling from Oh, six to 11. Yeah. And Arduino was coming out and what 2010
Host 3
I don't remember these we actually went from
Host 2
we went from the Freescale Freescale nine, that's 12 or the Fairchild. One of those three, it doesn't really matter. And then we went to the MSP 430 line. Basically, the MSP 430 line pushed out the old 912 stuff. And they replaced it with that. And then for last couple years, we moved to a ARM platform by Ti. Oh, I think was freaking hos to
Host 3
me, was an arm seven. Ah, I don't remember
Unknown Speaker
his camera what line it's from. So it's an S.
Host 3
For some reason, I was thinking Spartan, but it's
Host 2
not Spartan. But Spartan six, this was what we programmed in FPGA class.
Host 3
I think I did the same in mind. Yeah, yeah. I think I had
Unknown Speaker
to do I had to do a Bama Altera guy at heart. So
Host 3
Oh, yeah. Yeah, I think I think we had to do a turn signal project or something on an FPGA
Host 2
we had on our nine s 12. In assembly. That project? Yeah. Oh, that must have sucked. We actually the cool thing about that class was we had to design a robot in assembly and an iOS 12. Really? Yeah. So the crazy thing is the we didn't have a robot platform to put our code in. It was all simulated. I've got to find this stuff. Like where this has got to be online is a really cool project to do at macro fab. Yeah. But you wrote your robot and assembly in it simulated your robot. Like there's registers, you would hit that way, like turn motors and stuff. Oh, okay. Yeah. So you would write a value to a register location. And that would be like the motor speed for left track. Okay, so
Host 3
it's just a virtual machine. Yeah, yeah. Virtual robot. Virtual robot. Yeah.
Host 2
That's really cool. And so there was a competition at the end of the year. Yeah. When this competition was, basically everyone's robots were plopped into a big area gets a virtual space. And they fought a battle though. And we didn't have enough time to do any like, like, dude, because people were doing like, like, looking for, like other robots and stuff, where you had like vision that you can, like, detect other people. And you could like do people were doing like tracking and stuff. So they could, like, shoot a projectile and hit them. We didn't have any time for that. So we just made our robots spin around and just shoot. And we ended up coming in sixth place. Just from random fire. Yeah, out of like, 25 people. So yeah,
Host 3
so it was this something where they press to go, and then it printed out the result?
Host 2
I don't know. We weren't there for it. We came in and said you got sick place. Yeah. Well, you got we got our score at the end of the year. Yeah, like right before the final. And we were six.
Host 3
That's actually a really cool project. Yeah. That should there was a big there was some grad student or some PhD student who has all the backend. Oh, yeah.
Host 2
I really hope it's online somewhere and I can go find it.
Host 3
Yeah, that would be cool. Yep.
Host 2
And, yeah, that's the end. of Darfur section. Yeah, thanks. Yep, that was good. Yeah. And so that's the the McWrap engineer podcast episode 37. We are your hosts Parker Dolan
Host 3
and Steven Gregg. Better guys take it easy.
Host 2
On the next exciting episode of Macro vibe engineering podcast, Trey German returns from flight testing his GPS tracker, will he survive or go up in a cloud of blue smoke
