Carrie and Dave talk about his home-made DMX light system, entering the STEM space, industrial knitting machines, unicycling across Canada, failure and typing again, and designing/using aluminum printed circuit boards!
Check out his Twitter @unicycledave
Follow his unicycle adventures on his website: http://www.unicycledave.com/
(0:56 – 6:44) DMX Lights
Carrie: I have Dave with me. He is @UnicycleDave on Twitter, and he has unicycled across Canada, which is pretty darn impressive. He also likes hardware hacking and he's got some lights, which I am hoping he'll tell us more about, because they're DMX lights. I don't know anything about that system; I know that there are protocols and systems involved for theater and stage lights. I would love to learn more about that!
Dave: The lighting for this part of my room sucks so I went on this over-engineering journey of building some lights and that started probably a year and a half ago. I bought these little smartphone size, bi-color, lighting things. They're fantastic! I love them a lot, but they die, you have to charge them, they don't run off of power, you can't control them remotely, and they're not as bright as I wanted them to be. I did a little bit of shopping on Digi-Key, and I found these 95 CRI modules in two colors. I did some research and learned about aluminum PCBs. Something else that tied into the project is I had sliders that came from one of those high-end film mixing boards that have a servo controller on them. I thought, what if I built a lighting board from my desk? It just led to vastly over-engineering this problem.
Carrie: What is the system and protocol because I hear that all the time, but I've never really worked with stage lighting or theater lighting.
Dave: So, DMX is RS485. Which is a serial protocol that’s also used for industrial control and stuff like that. It’s just RS485 at 250,000kBd and it’s called DMX 512 because you send out 512 different settings, one after the other. You just repeat that over and over again, then the lights just listen for the start of the packet, find where they are in the address space, and go those are my values. They translate that into whatever they're supposed to do. The light cannot communicate back to the board in most setups. The board is like, do this and the lights do it.
Carrie: Just dumb receivers basically. For anybody listening, who's not familiar with RS485, you might already be familiar with UARTS or maybe even RS232 protocol or serial communications via those old school DB9 dongles that used to plug into the back of your computer, which USB has pretty much made obsolete. RS485 is a serial protocol, there tends to be a transmit and receive. For RS232, there's a dedicated transmit line, a dedicated receive line, and usually have ground. You can have other signals for handshaking, but they're not absolutely necessary. It’s very similar to transmit and receive UART communications that come from a micro-processor, but just level shifted and inverted a little bit. In order to hook up a processor directly to a computer, assuming that it has an old-school DB9 port, you would usually still have to have a chip in between that did a little bit of level shifting and converting. RS485 is similar, but it's differential. Basically, you can run it for longer lengths, and it is less sensitive to noise. I imagine it would be very good for theater applications where you might be running hundreds and hundreds of feet between your lights.
(17:34 – 22:55) Dave’s Work / Knitting Machines
Dave: I was going to say a little bit about where I work at the moment which deals with industrial circular knitting machines, which is really, really cool!
Carrie: Yes, I want to hear all about that. I’m a hand knitter so I think it’s really cool.
Dave: Okay, cool. So, this is a vastly different process, but it's still worth talking about. I work for Sheertex, a pantyhose manufacturer in Montreal that makes ultra-strong pantyhose. They have a special fiber that they use to make a knit that's stronger than most pantyhose. They work, they do what they say, they're a legit product! They can be quite expensive, so they're not for everyone, but I think the technology that goes into them is super cool. A lot of it's under NDA, but basically, the way the knitting machines work is they have 400 odd needles in them. It's a cylinder that spins around in a circle with a light vacuum pulling down the sock and it's kind of like a corking, I guess, is the name for it. There’re little fingers that are pneumatically actuated that actually dropped the yarn into the needles and pull it out based on the pattern that someone has programmed into the machine. We have so many of them and they speak RS485 so one of the things I had to do as part of the engineering work is we were trying to get them into our operations software. Turns out that you can talk serial to them if you say the right things in the right way. I got to build these little boards that actually do that, which was really cool. I don't have any photos of the machines, but it's worth looking up pantyhose knitting machines. You'll get videos that I don't even know, it's just one of these really cool processes. They're super intricate; it takes a long time to even learn how to program or use them because there’s a lot going on. You can do patterns, you can change the stitch height, so the taller your stitches, the more room you'll have in the leg for whatever thing you're doing.
Carrie: The looser the gauge, the more flexible it is.
Dave: Yeah. But the needles are a constant, they’re the heart of the machine. You can't change the number of needles and you can't change their size, they just are what they are.
Carrie: Right, so instead of changing the number of stitches in the circumference of a sock, they maybe change the yarn weight and the tension of each stitch.
Dave: Yeah, exactly!
Carrie: So, are these machines sort of specifically made for pantyhose or can they also do socks and hats and things like that?
Dave: Versions of the machines can do socks and I guess hats, I never even thought about that. Normally the yarn is quite thin.
Carrie: Yeah, that's got to be super tiny, tiny thread.
Dave: The yarns are wild, they float in the air, it's crazy!
Carrie: That must be nuts to try to work with yarn like that. That also is elastic, knitting yarn that’s fully elastic tension has got to be such an issue, consistency of tension as they're unwinding it from whatever spools or cones or whatever it comes on.
Dave: Yeah, they have a thing called a creel, which is all of the pipes and stuff that support the yarn packages that are above the machine. Then there's a bunch of feeders that sit in a ring above the needles that actually manage exactly what you're saying, the tension. When you get into stretchy Lycra and all this other stuff, the electronics are wild. I've taken apart some of these devices and it's so cool. They've got brushless DC motors and load cells and other stuff that they use on the fly to detect what the tension is and then adjust how much yarn is being fed into the machine. You also have to deal with temperature and humidity. I think a lot of industrial processes, which is one of the things I like about my job is kind of getting to learn more about that, like the intricacies of what makes those things work and what makes them not work and how to control them more accurately. It's a lot of fun!
(24:10 – 28:11) College/STEM
Carrie: How did you get into STEM and working on knitting machines?
Dave: One of the things I've always just had an interest in is electronics. Ever since I was a kid, I was dumpster diving for computers with my friends where I grew up it was just kind of my jam. I actually don't and never really have had much of a background in doing engineering on a more professional level. I absolutely have imposter syndrome about not being a “real engineer”. As I put LEDs on a circuit board that I designed myself – that works, got dammit!
Carrie: A college education is but one path and it is but four years of one's life.
Dave: This is super the thing and I'm slowly getting over it, but my background is actually in film. I worked on film sets for a number of years as an IAA certified data imaging technician and I used to do video backup. When the first digital cinema cameras came out, I was one of the first technicians that was backing up the files off of those cameras as my day job. It was great! The hours were terrible, but film sets were a good time.
Carrie: That’s the thing, right? You either have no project and nothing to do, or it's 24/7.
Dave: Precisely. My uncle introduced me to Linux at a young age and taught me how to use VI when I was 13.
Carrie: So, was he the one who mentored you with electronics and things in general?
Dave: It was more just the spark of interest, then it kind of ran from there with friend groups and exposure to other folks in my immediate community. There's a guy who ran an IRC (internet relay chat) server in the town where I grew up where you could get yelled at for writing C code if you wanted to. By that, I mean you would write C code, but it was the old school people were mean to you on IRC if didn’t know what you're doing. I don’t recommend it.
Carrie: I’ve never been on IRC, but I've heard about this.
Dave: Yeah, honestly, I'm glad that we're starting to move on from this kind of jam, but it was quite formative for me. I was always more drawn to hardware, but never had the resources for it.
Carrie: Yeah, it was really expensive, until recently, to make your own circuit boards or program your own circuit boards because the software was all very expensive initially.
Dave: Yeah, and now you can go grab a copy of KiCad and Fusion 360 for free (editor's note: sadly, Fusion 360 is not free anymore). I built my own 3D printer a couple of years ago, now I have a Prusa because I like myself and my time, but it was a very formative experience. I think the long story of that is my hobby experiences were very useful when they (Sheertex) were looking for someone to do prototype hardware engineering, machine interfacing, and data gathering stuff at Sheertex.
(48:20 – 56:04) Unicycling Across Canada
Carrie: Tell me about how you planned your trip across Canada. What was the remotest area that you went through and how long did it take?
Dave: I planned it just by… I don't know how to describe it. Sometimes there's stuff that you just have to do. I'm not sure that I ever really had a choice on the whole, you’re just like I'm going to do this. I started to obsess about it, and I really am a planner at heart. I think in general I really like knowing the details of how I'm going to do something. I had a pretty chill day job; at the time, I was working at Technicolor. I was just researching what the routes I could take were and how I would carry the stuff I would need to carry.
Carrie: Yeah, how do you carry stuff that you need to carry?
Dave: Carrying stuff is really interesting and everyone does it differently! One of the things I love about touring cycling is there's no real one size fits all for how to store your gear on your bike or whatever you're doing. I think it's so cool because when you're touring, you find other people and they set it all up differently. The way that I did it was I bought off-the-shelf bike racks, drilled holes in my frame, and put one facing forwards and one facing backwards. I bought 20L dry bags; big, blue dry bags from Mountain Equipment co-op.
Carrie: Because it actually rains in Canada, not like California where it does not rain, ever.
Dave: The weather was interesting at times, for sure. So, I want them to be waterproof and I bought replacement equipment for attaching panniers to the racks. I put a piece of Coroplast inside and then screwed that to the side because the problem with panniers for unicycling is that you get heel strikes because your cranks are so short.
Carrie: How is there even room for a rack on a unicycle?
Dave: I might have to explain a little here. I have a hole for a rack that goes here. The actual panniers would only hang down just a little bit. You get the clearance, but they have to be custom, and they have to be modified.
Carrie: Okay. That makes sense.
Dave: I was using a 36” tire, so there's a little more room for stuff, but I did carry a tent, drone, GH5 camera, tripod, sleeping bag – all this stuff. I had way too much crap with me. It was a lot of fun! It took me 111 days to do the trip and it was 9,250km; I have no idea what that is in miles. (5747.7mi)
Carrie: It’s a long way, it’s across Canada, right? It's across north America and not at the skinniest point.
Dave: Yeah, and I took a lot of side trips because I was like, well, I'm here and I'm in good shape. I would go to see friends; I would go to see stuff that was worth seeing that was on the way. It was really fun.
Carrie: What was the typical daily mileage for you?
Dave: So, my brain works in kilometers, but-
Carrie: We'll try to translate here.
Dave: You’ll just have to translate for me, or I can get out an app. But I would do a 100km a day roughly. About an hour’s worth of driving, I would do in one day. I don’t know how many miles that is. (62mi)
Carrie: Well, it depends upon how fast you're going. Are we talking freeway driving or?
Dave: Absolutely freeway driving. The reason why I didn't do it on a bike, which makes way more sense and is a lot easier, is you meet so many more people when you're that weirdo out on the road. People are like, what are you doing? Why are you here? How did you get here? Where are you going? On a daily basis, several people would pull over and they'd offer me snacks and places to stay and just kind of concerned people. I've received two bibles while riding my unicycle, I guess I looked lost a little bit.
Carrie: Right, this guy definitely needs God.
Dave: Yeah, if anyone needs a bible it’s definitely that guy. So, it's really cool because you kind of have that gimmick that opens up a couple more doors than you might, if you're more normal biker tourist type.
(1:00:42 – 1:08:55) Failure and Trying Again
Dave: It was definitely a long time coming. I had tried to Unicycle across Canada once 10 years previous, but that is a long and torturous tale. I didn't get super far; I made it to Alberta and then I went home.
Carrie: But that is also good for people to know. People tend to hear only about the successes and sometimes, especially when you're trying to do a big thing that you've never done before, it might take you a couple of tries to be successful and that's okay. That's part of the whole thing.
Dave: Yeah, that's a very good point. I don't often think about that, but failure is a super important part of success. I will also say through the wisdom of having failed a number of times in my life, sometimes it's important to fail and just walk away like you're never going to pick it back up again. Maybe in a year or two or whatever, depending on the project, the time will come back around where it's right to complete the thing that you wanted to do. Time is such a useful tool for overcoming problems.
Carrie: In knitting, we call that hibernating; projects are hibernating. When they’re giving you too much trouble or you don't like them, they're being a pain in the ass for some reason. Okay, putting this aside, hibernating now.
Dave: Yeah, and then when you come back to it with a fresh brain, after your subconscious has had some time to chew on it. There's something really cool about that. I like that on the larger scale, but also on the day-to-day scale where you're like, “Screw this, I'm out of here.” Then the next morning you're like, “That was easy, I should've gone to bed first.” I give up so easily now and go to bed. It's move number one for me; I’m like, “Nope, I'm going to go write some emails and go to bed.”
Carrie: I like it! The wisdom we've learned along the way, just give up and go to bed. It'll be fine tomorrow.
Dave: It's so true.
Carrie: Yes, Bob (from the livestream chat) is saying that very few people follow a strictly linear path through life, and many go through multiple iterations. I feel like that is so true and yet, it is so weird that sometimes we still feel like failures about not having this direct linear path or it still feels like the expectation somehow or the thing that we should be doing or the thing that we should be achieving. Why is there that narrative?
Dave: That's so true. One of the things that I aim for in my life overall, and I feel like I'm achieving it by and large is, setting my life up to have as many interesting opportunities come my way as possible by just saying yes to the weird stuff and going with it. I also recognize that there's a lot of privilege in that as well. I don't say that without qualification, but it's really cool. Sometimes it's worth it to take the thing that is interesting and just go for it because it leads to other opportunities that you might never have been able to see coming or anticipate. I don't know how true that is for everybody, but it's worked for me.
Carrie: I absolutely agree. Also, what you said about privilege is really true because if you're in a position where it's a daily marathon or a struggle just to meet basic minimum needs then oftentimes you don't have the luxury of doing the weird things. Or you're not in the head space where it sounds like a good idea or that you have the energy to take advantage of it.
Dave: Exactly, I just need to be really clear about that. Because I know not everyone has the ability to quit their job and take this other weird job that sounds like it'll be cool.
Carrie: But we can work towards making a place where that is possible, where everybody does have those opportunities.
Dave: Yeah, exactly, wouldn't that be great. It's what landed me learning about industrial controls and stuff like that, because I had gone and explored a lot of this stuff on my own. I don't have a traditional engineer background, like I was saying earlier, so there’s a lot of imposter syndrome. Being able to actually do stuff professionally really, really helps.
Carrie: I think it's funny too. The whole having a traditional engineering background because even though, yes, I have an engineering degree and you could say that I have a traditional engineering background, I did not take classes and what I did in college is not what I'm doing now. Yes, it's set me up for some things in certain ways, it definitely opened doors and gave me opportunities for sure, but the classes that I took in college were not what I'm doing now, at all. Engineering is such a huge, huge topic, right? I mean, you don't learn everything you need to know in college. Nobody could. You're always going to be continuing to learn and you're going to be learning on the job and learning from other people and maybe learning through your hobbies, too. I think that there's this real fallacy of, “I learned this in school and therefore, it is somehow more important.”
Dave: Yeah, totally. I'm getting over it, but it was a long journey thinking I can't do electrical engineering. What if there's stuff that I didn't learn in the magic sauce? Like the magic sauce class, they don't tell you on the internet.
Carrie: Most of the magic sauce stuff was stuff that the profs had learned by experience. Right? The really interesting gems of information that I picked up in college was when professors were telling you about these weird things that there was no way of learning except by actually just getting out there and doing them.
(1:22:05 – 1:28:00) Aluminum PCBs
Dave: This is really interesting trying to solder to an aluminum PCB!
Carrie: Yeah, tell me about that. I'm curious – Where did you have it made? How much did it cost? Was it really expensive compared to a normal PCB?
Dave: I learned so much making these. This was done with a credit with SeeedStudio and one of the options they had was for an aluminum PCB. For the least expensive type of these, you can't do vias. The original version of this board had these KiCad 2-pin connector layouts. Obviously, that doesn't work. I got a message back and they were like, you can't do that. So that's why I'm doing this really silly wiring. It's really interesting because the heat sinking is quite good on the board, soldering is really difficult because the minute that your iron leaves, it just hardens right away.
Carrie: Do you have an idea of how much more than a normal circuit board the cost would have been if you hadn't had the voucher or anything?
Dave: Yeah, I think it was between $50 and $75 for 10 boards of this size. The quoting is pretty good on their website; JLPCB may not do it, but Seeed definitely does it. There's one other place that will also do aluminum boards that I forget the name of, but they will give you a quote if you upload your Gerbers. It's worth checking, but the big thing is making sure that it's a single-sided board.
Carrie: No electroplating aluminum.
Dave: Yeah and I think if you pay a fair bit extra you can do it, but the process is a lot more complicated.
by: Carrie Sundra
Do you want to try out surface mount soldering, but aren't sure what supplies to get? Or are you just curious about what others use? We've amassed two lists - one is a list of the most budget-friendly supplies we've found that don't suck, and the other is a list of the brands and supplies we like best and use regularly. Let's fire up those irons!
Note: none of these are sponsored or affiliate links, we don't profit from our recommendations.
Budget-Friendly Supplies That Don't Suck
We get it. Sometimes you want to try something out but don't want to shell out massive amounts of money to just learn that you don't like something. Here's a list of supplies that hopefully won't break the bank, that we don't mind using ourselves. We also talk about why we like them, or what we look for. This is also the bare minimum, it is definitely nice to have some nicer tools, but is not required for starting out.
What We Prefer:
These are tools and supplies that we use every day. Alpenglow-approved!
In our previous blog post, we Put the U in FUnicorn; this month, we’re all about the F! With our shield headers in place, and so many available Arduino shields, the world is our oyster, or whatever the unicorn equivalent is – probably some kind of fancy berry or something! In our previous blog post, we alluded to a Wi-FUnicorn, but that beast will have to remain mythical for now, since we ran into some pin conflicts and other issues that made its performance a little less stable than we’d have typically preferred. So, we headed back to the drawing board with a blank canvas – or more accurately, a blank proto shield – specifically, Arduino’s Proto Shield Rev3 for the Arduino Uno, which in addition to the typical prototyping area found on most boards of its ilk, has those really nice labeled pins like the newer Arduino boards, and also a great little SMD area where you can add a 24-pin (or fewer) SOIC.
The FUnicorn is literally one flashy pony out of the box, but we wanted to really make it shine. The protoboard made it easy to add more LEDs, but that wasn’t enough – we wanted to really put on a serious dog and pony show. So, we thought: what if we made our filly a bit more philharmonic? Browsing audio shields, we noticed a common theme: they typically used SPI, and since the FUnicorn LEDs already use those same pins for PWM pulsing, they were unavailable. However, I2C, UART, analog, and many digital I/O pins are free and clear! So we looked at other modules, eventually settling on the $15 “WayinTop Sound Module Button Control Music Voice Player Programmable Talk Chip” on Amazon, which rather than relying on a complicated SPI bus, would allow us to trigger a preloaded MP3 with high or low, similar to a button.
Due to the its capacitive touch interface, which works by using a pullup to stick a voltage on a pin and measure how fast it decays, the FUnicorn must constantly poll to see if its giant golden likeness is being interacted with. This presented a challenge for our additional functionality that we wanted to layer on top, since we wanted our LED and audio to have some specific timing characteristics in order to put on the show as we’d envisioned it. In the end, we solved this by playing a short LED animation as part of the capacitive touch loop, counting down the number of cycles we needed to approximately match the length of our audio, after the initial built-in animation (which is blocking) has completed. An extract of this code can be found below, and the full example can be found in our GitHub repo, or the Examples > Alpenglow FUnicorn menu if you already have the library installed, and have updated it.
With everything now working precisely how we envisioned it – or close enough – allow us to demonstrate to you the glorious result:
We couldn’t think of any lyrics that better represent our marvelous mare than Mermaid Sisters’ Galactic Mermaid from Shinichirō Watanabe's Carole & Tuesday (which is where the "B" in FBUnicorn comes from!), though of course you can load as filthy or clean of a song as you like onto the board’s microSD card. If you build this project, let us know what song you chose, or maybe in the next installment we’ll get that Wi-Fi working and turn the FUnicorn into a networked jukebox so that you can pick your favorite track remotely!
by Carrie Sundra
This time of year is a conundrum. While I'm grateful for the friends and family the holidays bring together, I also have to acknowledge that Thanksgiving is a colonizer's holiday. My earliest memory of the story of Thanksgiving, taught to me in school, was that indigenous people shared their food with white settlers, taught them about the new-to-them foods and game, and that knowledge and generosity saved them from starvation that winter. Later I learned that the white settlers went on to commit terrible acts of genocide against indigenous people and stole their land to found the country we live in now. I feel like Thanksgiving should be a narrative about giving thanks to indigenous peoples, but instead, our cultural narrative has become gratitude for the things and people that myself as a white person is surrounded by. It feels pretty hypocritical and gross.
All of us at Alpenglow Industries would like to acknowledge that the land we operate on, and that our team members work on, is all the ancestral homelands of several different indigenuous peoples. Our small team is spread over 3 time zones and 2 countries, and we each had a bit to say about the land we live on.
Tiohtiá:ke, (Montreal) is on the traditional unceded territory of the Kanien’kehà:ka, and has long served as a site of meeting for many First Nations including the Kanien’kehá:ka of the Haudenosaunee Confederacy, Huron/Wendat, Abenaki, and Anishinaabeg. We recognize and respect the Kanien’kehà:ka as the traditional custodians of the lands on which Alpenglow Industries Team Members operate today.
Hundreds of years before Ann Arbor, Michigan was founded, the Anishinaabeg, meaning "The People" and including the Odawa, Ojibwe, and Potawatomi tribes, and the Wyandot tribe lived on the land along what are now called the Huron River and the Great Lakes. Collectively, the Odawa, Ojibwe, and Potawatomi form the Council of the Three Fires and it is their unceded land that our team members live on and work from today.
San Luis Obispo, California, where Alpenglow Industries in headquartered, is the ancestral home for over 10,000 years of the yak titʸu titʸu yak tiłhini tribe, "the people of the full moon", also known as the Northern Chumash Tribe. We respect the deep understanding the yak titʸu titʸu yak tiłhini have of the ocean (yat spasini) and tides, and as makers, we respect their expertise in intricate basket weaving and skilled jewelry-making featuring local abalone shells. We recognize that the yak titʸu titʸu yak tiłhini are the longtime non-nomadic custodians of these unceded lands that we occupy.
We will be donating to local organizations representing these Nations and tribes at the end of the holiday week, in recognition of the indigenous people whose generosity and empathy brought about the Thanksgiving holiday, and in gratitude for the work that indigenous people and their tribes do in our communities today.
Carrie and Tommy talk about his 555 synths, the OKAY and the Poly 555, and his upcoming arduino-based keyboard called the Scout, plus switches, light pipes, and 3D printing and design, while Carrie solders up his APC Atari Punk Console noise-maker.
Check out all of Tommy's cool musical inventions at www.oskitone.com
Carrie: Hello, how's it going? I am Carrie Sundra with Alpenglow industries. Welcome to the weekly Wednesday solder sesh, where we come and hang out and put something together! This week I'm super excited because I have Tommy Marshall from Oskitone. We're going to be putting together this kit right here, which is his APC Atari punk console. Also, I have his poly 555 which is an amazingly fun little synth that is made of 555 timers and is polyphonic. It has like one separate timer circuit for each key, which is simple and overkill and lovely.
Tommy: It's a joke instrument, yeah.
Carrie: Yes. It is an excellent joke instrument though.
Robyn soldered it all together and she had fun doing that and then tuned it. You can now see the extent of my piano skills. The pressure is on, I've never done this live before, so I'm probably going to screw it up. All right, here we go.
Carrie plays a halting rendition of Chopsticks. She obviously has little musical training.
That was chopsticks. So yes, that is the extent of my piano playing. I think all of the other songs I know are only one tone at a time, so they don't show it off quite as well.
Tommy: And Carrie, how many years of piano lessons were paid for, for chopsticks? Was that 4 years?
Carrie: Oh, well, well for chopsticks, I looked it up on the internet, so it was about five minutes of YouTube. Then I needed to refresh for this week. I really needed to prepare for that recital, so it was five more minutes on YouTube and maybe three practice sessions. Yeah.
Tommy: You know what, honestly, that's pretty good. 10 minutes
Carrie: patterns, right? Recognizing patterns and remembering the pattern. That's what it is for me, at least, because I'm not good enough to associate a sound with a particular key. So, for me, it's all, what is the physical position?
Tommy: The dirty secret of musicianship is that for a lot of instruments, especially guitars and stuff, it's all just patterns. You'll learn to do this little box or something and then some of you change the key and you'll play the same pattern in different spot.
Pianos are not great because this little layout doesn't lend for transposition easily. Transposition is where you change keys because the naturals and the accidentals, the whites and blacks are a totally arbitrary thing, and every key kind of looks different and your fingers do different things.
It’s like a muscle memory thing that you either learn or you don't, or maybe it doesn't matter. Maybe you have a keyboard that does a key transpose or something. Anyway, the point is that they're easier instruments for knowing how to play. A keyboard is good because it's like a known thing, right? There's infinite frequencies and keyboards are like, there's just this many and it's multiplied, and they always look like this, and it's been that way for a long, long time. So, you can look at any keyboard and be like, yeah, I basically know how to play that.
Carrie: I'm going to start to solder up the APC while we do a little bit of chatting. So, I'm super curious about so many things. First maybe tell us, how did you get started on the whole 555 musical instrument kit path? How many 555 timer-based instruments do you have?
Tommy: I have two that I'm selling and probably three, if you count the old OKAY instruments.
Carrie: Oh yeah, what happened to the old OKAY instruments?
Tommy: They were really hard to put together, they took a long time. I thought the ROI on them, as a maker, was really low. I thought if you're spending a long time on something, it should give you more.
As a one-person maker business, I field all the support questions. So, I saw the most earnest effort not get rewarded and all these questions that were like, I should have just designed this better. I should have made this a lot easier for folks to put together.
Carrie: That was like the first thing that you put out right?
Tommy: Yeah, it was, it was a real learning exercise. Cool. Um, and I, I hope, I hope that everything that I make, I get to learn from the previous things, you know what I mean? So, I hope that I learned from the OKs failures and put those lessons into the poly 555 and now the new Scout thing, which just launched the other day.
Carrie: Yeah, the poly 555 was pretty easy going together.
Carrie: What inspired you to make your first 555 instrument? Take us down the twisted path of your brain.
Tommy: What can I say? I learned how to solder around 2013. I wanted a hobby that was technical, that didn't use a computer, and electronics fits the bill. I did the things that hobbyists do, I did various kits and stuff, and I started building my own circuits on breadboards. One of the first things that folks will do is blink and LED. It turns out if you blink a pin real fast and it's hooked up to a speaker, you’d get a little tone. If you give it the right components, you can fix the frequency of that tone. I'm a musician, so I put the things together and I was like, okay, I'll just make some instruments with these things. The OKAY which we've mentioned before and looks like this, was a ridiculous thing. It's a chunky boy. You put it on your shelf and it's like a little conversation piece. I think the poly 555 is also a conversation piece, but probably for different reasons.
You asked about 555 timers. I've used them because that's what I was kind of familiar with, but there are other ways to make square waves. I've made different, weird one-off things with different waves. Schmidt triggers, hex inverters, quiz me later on what the CD 4,000 numbers are for these because I don't remember. I liked the 555 because it's kind of like a running joke within the electronics community. For folks who don't know, you'll see anything, anything anywhere, and there will always be one comment like, “Ah, I should have used a 555.” like, no matter what it is. Save the world, man. I could've done it with a 555.
Carrie: I mean, you know, you can really do anything with the 555 timer. I think that's the main theme, right? Any circuit that exists could probably be made using a 555 timer.
So, APC stands for Atari punk console and is basically used to make fun and obnoxious Atari-like sounds.
Tommy: Yeah, APC makes some annoying sounds. It was made famous by Forrest Mims in one of his books for radio shack long, long ago. Seventies, I think. It's fun. It's obnoxious.
Carrie: I've said this before on previous streams, but my mom just hated nothing more than repetitive, eight bit arcade noises. They drove her crazy. I wasn't allowed to have a normal Nintendo console as a kid. I finally was able to get a game boy, pretty much because my dad got it for me. I used to be forced to wear the headphones a lot so that she didn't have to hear all of the noises, which you know, for me was a key part of the game. Right? Some of the best parts were all the fun noises.
Carrie: Let's see. Oh, yes. Don't bend the speakers leads. I am going to solder the wires and I saw that you include holes here for strain relief, which is super cool. That's always nice and something that I forget to do in my boards sometimes. So it's always nice to have a reminder. So feed it through its holes. I'm guessing that we want to feed them from the bottom to the top and then solder them over like this.
Tommy: I'm trying not to spoil it.
Carrie: I kind of want to see a photo. Because, it might make a difference whether the wires exit the bottom or the top of this board for routing purposes.
Tommy: There is a picture of a finished PCB at the top. But, there could be step-by-step photos, which isn't a bad idea.
Carrie: This is a small enough board though. I think you're fine with just one photo. Okay. So now those are bent over and I'm going to pull this through a little bit, just so these guys kind of are more or less in their final resting position. Making sure that red is to plus and black is to minus.
Tommy: One reason I like those relief holes on the PCP is that it kind of helps hold it in place while you're soldering, without those you're trying to binder clip it in, you're doing a blob or a tack or something. So, the relief is nice because it's a mechanical thing. I think that helps assemble it too. If you can spare the space on the board, I think it's always nice.
Carrie: So, we recently had a tantalum capacitor blow out. So I am now triple checking tantalum, capacitors. I really hope I have mine in the right way. I think I do. I think I do from the instructions, but I don't know, the one in your picture almost looks different maybe, but I don't know if I want to second guess myself right now.
Tommy: Let's see your board again.
Carrie: Let's see, I have the minus on the side next to the speaker. We might not be able to focus very much closer than that, but definitely the white is to white. Yeah, hoping that I don't blow things up.
Tommy: There's an electrolytic. There's a couple of ceramics on there.
Carrie: Yep. Just one electrolytic, one tiny one. Well shoot, should we, should we try it? Robyn definitely has some PTSD from that.
Tommy: All right.
Carrie: Okay, and I think our switch was to the off position probably since nothing's happening.
Tommy: I think it's good. Do you hear anything?
Carrie: I hear a little bit.
Tommy: So RV 103 is volumes. It's a quiet thing, thankfully.
Carrie: My mom would approve. It's pretty great. Well, it's cranked to 11.
Tommy: Yeah. Nigel Tufnell would like that.
Carrie: I'm going to try the other one, more tone and pitch. Oh, that's fun. That is definitely fun. All right. Let's put it in this case. I have some questions about your mad 3d modeling skills here. I am very impressed with this case. First of all, what printer do you have? Because I'm always interested to hear what printers people like.
Tommy: I got one of these Prusa’s, one of the bigger ones, not the latest, it's a couple of gen's old. I like the Prusa. All of that is in PLA, which is the standard relatively cheap stuff.
Carrie: The thing that I liked about this so much was that this slide is really, really nice. I look at this and I'm like, man, if I tried to print this, that under cling or the under the lip would be all sorts of crappy and I'd have to clean it out. It would just never quite work very well. So, when I got this and it just slid so smoothly, I was like, dang that's impressive. Can you share any tips or tricks you have for making parts that fit together so nicely? And, and do you have to do any finishing to these?
Tommy: I try very, very hard to design things that print nicely and don't require a lot of post work. Uh, rewind. When I design kits, I'm kind of designing for a couple of different audiences. 1. Is the electronics person, is this easy to solder? 2. Is it easy to assemble at the end? 3. Can your printer do this well? DFM design for manufacturability. What you’re appreciating there, and I thank you for appreciating it, is that the tongue and groove joints of that thing. This goes together pretty well because there's this trick you can do where, if you ever have to print something that goes out, instead of printing it as a T, you print it at a 45-degree angle.
Carrie: Yeah. Now I can kind of see that a little bit in the profile.
Tommy: The Scout’s enclosure kind of snaps together, but it uses the same tongue and groove joints with a lot of 45-degree angles. The last thing you want to be doing is like cutting out supports from very tiny places. A lot of things that I do unfortunately have to have supports because they're weird. But whenever I do that, I try to make them big things that you can clunk out easily or maybe things that don't really matter. A joint like that needs to be really tidy. If you're anything like me after you put this together, you’ll fidget with it and it’ll become a toy.
Carrie: Nice. So now I gotta fit the little switch in,which I think goes in that way. That seems to be proper.
Tommy: I'm curious what you would call a piece like that. There's this adage that one of the hardest things in engineering is naming things. I had the hardest time naming this little piece.
Carrie: You know, from an electronics perspective, I would call it a switch cap.
Slight caveat, this is super interesting because you have a vertical switch here. And yet you have a right-angle switch cap. That right angle switch cap, actually keys in here to the vertical switch. I would never have thought of doing that that way at all, because I would have just been like, oh, well, I'm just going to get a right-angle switch. Yeah.
Tommy: That would be the smart thing to do. Let me share a fun fact about my version of APC and it relates to the poly 555. So, the poly 555 has an L-shaped PCB and it's really big and expensive. Fab houses don't care if your thing is L-shaped or heart shaped or whatever shape, you get charged by the rectangle. So, I was getting charged for this big chunk of space that I wasn't using. I was wasting money. What I did was, I literally just grabbed that radio shack book. I was like, what is the circuit that I know that everybody will know? I very quickly did the step tone generator, and I threw it in that corner. I basically did nothing else. I kind of changed the pots on it, but it worked, and it was good enough for me. It existed like this just in PCB form for like a hundred of these. I had a lot of these PCBs before I ever started on the design for it.
Carrie: Bold, very bold. I like it.
Tommy: So that is why that switch is kind of weird, because I kind of thought that I would have a switch that exposed out of the top of the thing, like the switches right here. But it's a weird spot and to have that switch exposed out at the top, I think would have been ugly. So, I made it instead expose out the side., This switch cap, as you say, I call it a clutch because it’s clutched onto the actuator. I was careful not to call it a switch itself because it's not switching anything. It's kind of like an actuator on the actuator, I think that makes sense.
Carrie: Switch actuator is also something I believe I've heard for this type of thing. Especially when it's something like this, where you're translating motion into a different plane, because I generally associate switch caps with just going on the top.
Tommy: That’s what I thought too. I thought a switch cap is a thing that just goes on top.
Carrie: Yeah, so I think actuator might be the more proper term for it.
Tommy: I thought that actuator is the name of the part that sticks out of the switch too.
Tommy: Naming stuff is hard.
Carrie: Yeah, it is. It's hard to search for things too when you know what you're looking for, but you don't know what it's called by the people who are selling it. Learning terminology can be a real challenge.
Tommy: Yeah, this is something that I struggle with because I'm not an industrial designer. I'm not an electrical engineer. I don't know. I don't really know anything about anything.
Carrie: Well, you're doing a great job at both.
Tommy: I find myself just making up words all the time. My code is just littered with these words that probably don't mean anything to anybody else. I'm like, ah, somebody else looks at this code, I hope they understand this. I hope they can get it.
Carrie: I like it. I also have an L-shaped board and I did not come up with something as clever as your solution. I panelized it myself and I ordered them as a panel. So, I panelized it wit the cutouts, it was kind of shaped more like a flag, so I was able to nest them. The same thing, those boards were going to cost me almost twice as much money if I didn't do that. I did get the prototypes made by OSH park. It was funny, I even got a comment after I had ordered them, whoever processed the order was like, Ooh, nice nesting.
Carrie: It's a super fun build. I also think that it's super approachable kids, I think because it's not a kit that has a million different parts, you know, and you get a lot of really great instant gratification from it. I think it's awesome. So, tell us more about the Scout and could you play something on it or the poly 555.
Tommy: The Poly 555 Is this. It looks like this. There are 20 555 circuits, they're all identical It has keys. It's got this thumb wheel on the side. Like it's an old nineties Walkman. It doesn't slide together like the APC, but it uses a lot of the same enclosure parts and kind of screws together. There's some hitches here so this part is held together right there. And this screws together, it's basically top and bottom. It's takes 20 hours to print. There's a big old speaker in there and a nine volt battery.
Carrie: I love that there's an LED per key too.
Tommy: Next time you have me on, maybe I'll have a better camera set up, but you got to trust that I was playing that. I can do one blue scale and it's C blues and that's the only blue scale I can do.
So that is the Poly 555, available at Oskitone.com. The other thing that I launched Monday is called the Scout. It looks much smaller, much cuter, 17 keys powered by an atmega 328, which is the same microcontroller used by the Arduino UNO. It is called the scout because it is my first foray into microcontrollers. I don't really know much about much, but I knew that I wanted to get away from 555’s and I wanted to make something that could be done in a much shorter time. So, this takes about 45 minutes to put together to solder and assemble. It still takes like nine hours to print because you know, printers can only go so fast. It has the same kind of switch caps, switch clutch, the volume uses the same code as the APC, but it looks different. Instead of a Brody knob we have a little dimple and there's no spokes. It uses a lot of the same code. It has a line out, first time playing with headphone jacks. It's a stereo Jack, but it's wired as mono so you could use headphones and I tried to make it so that at max volume it won’t deafen you. It has a UART do you know what UART stands for? I don't remember.
Carrie: Universal asynchronous receive transmit? I think, I'm not sure if the U is universal or not.
Tommy: When you turn it on the APC has its LED exposed as does the poly 555.
Carrie: I love that light pipe action too, by the way. The “ah, do I really need a light pipe? No, I'll just work it into the print. “
Tommy: I will. I always want a light pipe. There are things that I keep coming back to. I always want to make a real light pipe. If I can figure out a design that uses them well and make sense to get them manufactured, I probably will because I just keep coming back to them.
Carrie: You know you can buy light pipes too, right? :)
Tommy: You know me, I have a disease called “not invented here,” which means I want to make everything from scratch. That's why all these knobs are like this. This is why I'm not using like off the shelf mini controllers or whatever. The Scout does not have an exposed LED instead, it's kind of a secret thing that when you turn on it, there's a little thing inside the thing. Also, the speaker is not exposed, the speaker is actually right here, and it uses the keys as a grill.
Bob asks, “Does the UART on the scout allow for reprogramming?” It does, you hook up an FTDI cable, sold separately, and you plug it into this and then your computer talks to it just like an Arduino Nano. I ship all the chips with a bootloader so that you can do that.
It sounds like this.
At this point Tommy holds the Scout up to the camera with one hand and plays it without the other, barely looking at the keys, making playing music look effortless.
Tommy: It is monophonic it, uh, monophonic means one note at a time. But yeah, it's fun. I think it's a nice little kit for folks new to electronics and people who are familiar with Arduino. I hope people like it. I put it out Monday. I'm still kind of promoting it a little bit. Thank you for the opportunity to promote it right here.
Carrie: Of course, of course!
Tommy: I'm hopeful that people like it, but I'm also hopeful that it unlocks me to do new, weird things. You know what I mean? Anytime I put something out, people are like, “can it do MIDI?” And I'm like it’s all analog. Like, it wouldn't be worth it. And people ask, “can do filters, what about envelopes?” This still doesn't really do any of that.
Carrie: This is more of an instrument than a synth, right? Like that's how I kind of think of it.
Tommy: Yeah. It's, it's I don't know. It's an overloaded word. When you say synth, that means a lot of different things for a lot of people.
Carrie: Well, you see, I know nothing about this! There's synth drama. I love it. I'm not surprised. I mean, you know, there is knitting drama. There is crocheting drama. There is spinning yarn drama. There is all sorts of drama in every community. So, it's like, of course there's synth drama and discussion about what is the meaning of synth and what exactly is the meaning of yarn and what constitutes a fabric? It's fun having those discussions,
Tommy: right? Yeah. I bet I love it about as much as you do. Anyway, I'm hopeful that this will unlock some of those things and I'm also hopeful that it will give me a foundation to start doing weirder things that are less keyboard-y. Pianos are like the 555 timers to me, it's like a known thing. There's value in using a thing that already has precedent and people have a general understanding of like the, the ins and outs of this thing, but we shouldn't be beholden to it. You know, the world is our oyster. Why shouldn't we do weird, weird stuff?!
Carrie: I like it.
Tommy: Maybe I'll do some weird stuff.
Carrie: I think you should do lots of weird stuff
Tommy: If people buy it, I will make it.
Carrie: yeah. I'm like, well, even if people don't buy it, I'll probably still make it, but that's not a very good business decision. I don't recommend that, but it does happen sometimes.
Tommy: Yeah, no, I hear ya. It's hard to be both an artist and a business person, you know, it's, uh, those two things can be at odds when they both meet up, it can be a little awkward.
Carrie: Yeah, definitely.
Well cool, this was super fun. Thank you so much for coming on and everything.
Tommy: Yeah, this was great. I'm so glad that it actually worked. Thank you for having me. Thank you for buying, buying my wacky things.
I also want to say, you know, I'm a big fan of you and of Alpenglow. And I recently learned what Alpenglow is. I love the poetry and the name and the mission. And I'm so excited for your new space, new expansion, your new people. I'm real jazzed about everything that y'all are going to do. And, uh, I'm weird on camera, but I will do this for you.
Carrie: Well, thank you because I feel like I'm weird on camera too. So, thank you for being weird on camera with me, I think it all works out. Cool. Cool. Cool. Well, awesome we'll definitely keep in touch with each other. Give Tommy @Oskitone a follow, give him some retweets, sharing the Scout love. He has really cool things, he has a range of stuff on his website and even has like a little sequencer that I also got at the same time.
That was a pretty inexpensive little kit so if you're not quite ready for the poly 555 yet, there's still a lot of cool stuff.
Tommy: I'm trying to better serve the markets out there. So, if you like my aesthetic, but you don't see something that is for you, let me know.
Cool. Thank you, Carrie.
Carrie: Thank you. And thank you everybody for watching, we will see you next time.
by: Carrie Sundra
A few weeks ago, I had the awesome opportunity to visit Debra Ansell of GeekMomProjects in real life. There are all sorts of colorful creations in her electronics lair, but this super cute Blob caught my eye. It had a happy bounciness to it, these great big googly eyes, and it lit up in fun patterns that were reactive to her voice. When she asked if I wanted to make one, I was like "HELL YEAH!"
She used a 200 light strand and bent each LED into a swirly pattern, and then zip-tied them to each other as she went around. I thought - hmmm, I wonder if you could do it without zip ties? After a few weird wraps at the start, it occured to me that I could totally knit the wire together, making one stitch per LED. I did this all with my fingers, so I could easily fish the wire through the stitches and turn the LED so it was right-side out. Mine isn't voice-reactive yet, but that will come soon! Here are instructions so you can finger-knit your very own Blob, and you can also check out Debra's post on her Blob.
Step 1 - Start
Start at the end nearest to the USB dongle. Form 8 loops, one loop per LED with each LED at the top, and twist each at the base three times to lock in the shape of the loop.
Bend the loop in a circle, and wrap the wire going to the USB connector to fix the circle.
Step 2 - Knit
Pull the next LED through the very first loop you created. This one will be a little offset from the middle, and that's OK. For the next one, bend a U-shape with the LED in the center. Pinch it with your fingers, and pull it through the next loop.
Keep pulling LEDs through loops, and as you go, turn the LED on the strand so that the rounder more translucent "top" is facing out. The Blob will eventually start to form a tube shape. You may need to bend each "stitch" inward as you go, to prevent the previous one from popping out (or in knitting parlance, "dropping stitches"). You'll figure out what kind of bends work for you as you go!
Step 3 - Finishing
When you have 2 LEDs left on the strand, fish the end of the strand through all the "active" stitches - the ones that don't have another stich on top of them. Pull through and cinch as much as is practical.
Wrap the last few inches of the strand around the cinched hole to fix it in place.
Add googly eyes! The end you just finished is the head, it's a little more practical for the string and USB dongle to exit the "tail" end. You might want to hot glue the googly eyes to keep them on, or add tape to the underside.
Congratulations! You've now made your very own Blob. GeekMomProjects will also be writing up more instructions for how to create a Blob with the zip-tie swirl method, and for adding sound reaction with a Micro:Bit, and we're working on more microcontroller options, so keep checking out this blog and her blog and follow us on twitter and GeekMomProjects on twitter for updates!
Want some company for making your Blob? Join Debra and I for our Build-A-Blob-Workshop livestream next week Oct 13 2021 at 5pm Pacific (which will also be recorded), watch it here.
The Alpenglow Industries FUnicorn is a fun way to share a special message, and the Full Kit adds to the fun with a big F’ing button, for remote detonation of your F bombs. But what if you want to make the FUnicorn your own – and create a more-than-one-trick pony? Also included in the Full Kit are user-solderable headers, so that you can add an Arduino shield and create the equine masterpiece of your dreams*!
*provided that your dreams are compatible with 3v3 I/O
In order to not perforate the FUnicorn’s majestic form on the front of the board, we used surface mount headers rather than through-hole. This cosmetic decision means that you may find the headers harder to solder than other Arduinos you may have come across in the past, but, you can do it! If you believe in FUnicorns, we believe in you!
We recommend using any shield you may have handy to hold everything in place. Tack opposite corners to maintain alignment, then work your way along the rest of the outer pins. If everything is looking good, go ahead and carefully remove the shield. Remember at this point that the headers are only half-soldered, so if you yank it off with full Clydesdale strength, there's a chance that the headers – and even the pads that they are attached to – could come off with it, causing permanent damage. So please wiggle gently! With the shield out of the way, you are now clear to complete the interior pins (below, left). You may experience some balling or other flow issues – feel free to reflow any problematic areas. At this point, your board should look like the below right:
To confirm alignment, go ahead and reattach the shield, verifying that all of the pins are correctly seated and insertion/removal does not require an unreasonable amount of force. At this point, you are ready to put the U in FUnicorn, and give your idea wings (which would perhaps make it an FAlicorn?!)! If you want to be a nerd (don’t worry, we love nerds!) you can sneak ahead by completing Step 3 in our Hackaday instructions, or if you’d prefer to nerd out vicariously, stay tuned for the second part of this series: the making of the Wi-FUnicorn!
by Carrie Sundra
SOT-523. Is that one I can hand-solder, or is that one of those ridiculously tiny packages? SC-89. Is that basically the same as an SC-75, just one has bent pins and one has flat pins? And wait, are those both actually the same as a SOT-523?
If you're been around the block with PCB design, you'll know exactly the frustrating mess of nomenclature I'm talking about. After finally having had enough of it, I spent 3 weeks reasearching standards, poring over countless datasheets, and using Digi-Key's priceless parametric search to bring you...drumroll please....the WHAT THE SOT?! and FOR THE LOVE OF SOD! printed circuit board footprint rulers.
Not only did I want a tool that would help me identify the right size part to put into a design, but I also wanted a tool that would help me identify a drop-in replacement when the inevitable stock issue or obsolescence issue came up. Because there is NOTHING worse than having to re-spin a PCB just to change a footprint!
Did someone say stock issue? With the worldwide parts shortage the electronics industry is currently experiencing, my email has been bombarded by panicked current and past clients who are trying to order boards only to find that 1/3 of the parts are out of stock. Having these handy references on my desk has allowed me to quickly and easily identify alternates and save some manufacturing schedules. Warning: side effects may include your clients or boss thinking you have superpowers.
Here's my process for identifying an alternate. Let's say a trusty N-channel MOSFET in a SOT-523 package that you designed into a board is out of stock for 52 weeks. Your client might be sweating bullets, thinking their manufacturing schedule and income for the next year is completely shot. But you're cool, calm, and collected because you have the WHAT THE SOT?! ruler and Digi-Key's parametric search.
First, you type "transistor" into Digi-Key's search bar, and select "FETs, MOSFETs - Single".
Now to narrow it down from 41k results. Of course we want only parts that are "In Stock" and they should be "Active" so that we can (hopefully) continue to source them for several years to come.
That gets us down to a mere 10k results. Ok, now to the specifics. We want an N-channel FET, and we want it in a SOT-523 or footprint-compatible package. Looking at our trusty WHAT THE SOT?! ruler, we see that there are flat-lead versions that will very likely fit on our board that used a gull-wing part. So we scroll the Package/Case category, using a CNTL-click to select all compatible parts. Check out how the Suppliers have even more names for the packages!
This finally brings us down to a very manageable 25 parts. Now you can go onto other features, like Vgs, Rds(on), etc, to find the most compatible one.
I hope these ruler footprint references help you too! WHAT THE SOT?! has transistor patterns from 3 to 8 pins, from as small as the insanity-sized SOT-883 to the big whopping D3PAK. FOR THE LOVE OF SOD! has diode and passive 2-pin patterns from the finely-ground-salt-sized SOT-962 to the mighty SMC. Each footprint has the more colloquial "small outline transistor" SOT or "small outline diode" SOD size names (with alternates), as well as the equivalent JEDEC "transistor outline" TO or "diode outline" DO names, as well as the Electronics Industry Association of Japan SC names.
You can buy these handy footprint rulers from our Tindie Store, or from Digi-Key. We're a Marketplace seller, we ship fast and have a $5 shipping option.
by David "ishotjr" Groom
16x2 character LCDs are a great way to add a visual output to an Arduino project, though they are somewhat inflexible in terms of the information that they are able to display - for example, the character size and font is fixed. Or is it ? By using the 8 available user-defined characters, it's possible to add your own custom glyphs - and if you're clever, you can combine them to completely transform the capabilities of this humble display!
Our own resident clever clogs Carrie published the BigNums2x2 library a while back as a byproduct of another project she was working on. This library redefines the 8 available characters to create Big Numbers which each occupy 2x2 characters! As explained in her original blog post, Carrie was inspired by other, larger examples of the same technique, using 3x2 characters. Combining characters in this way revolutionizes LCD usage, since you can now easily take a reading from across the room, making it ideal for at-a-glance data. One of the most common numeric values that humans like to glance at is temperature data, so I thought it would be fun to create a simple thermometer using a DHT11 and an Arduino Uno, in order to put the library through its paces.
I happened to have an unused Adafruit RGB backlight positive LCD 16x2 handy, so I soldered on the headers, then followed their wiring guide to ensure everything was working. The particular LCD that I'm using is RGB-backlit, but to keep the project somewhat generic and applicable to standard single-color displays, I resisted the urge to get fancy, and only wired up the R(ed). There's quite a bit of wiring required, with 12 of the 16 pins populated on the standard LCD (the RGB adds another two pins for controlling green and blue). The Adafruit tutorial has an excellent description of how to hook it up, as well as what each pin does, but here's a cheat sheet so that you can check your work, or skip the long version:
Once you've got the LCD wired up, it's a good idea to give it a quick test before proceeding, so grab the built in HelloWorld example from File->Examples->LiquidCrystal. The Adafruit tutorial uses different pins than the Arduino default, so we'll need to tweak the code slightly; instead of:
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
for the way we wired it. Compile and Upload the sketch, and you should see a lovely "hello, world!" on your LCD. If not, hit us up in the comments and we'll try to help you figure out what went wrong!
Now that we know the LCD is working, let's have a look at the temperature. I'm using the commonly available, inexpensive, DHT11. It's not the fastest or most accurate way to measure temperature, but it's cheap, and good enough for our purposes. Hook the middle ("out") pin on the DHT11 to digital pin 2 on the Arduino, and the + and - pins to 5V and GND respectively. You'll need to install the Adafruit DHT sensor library as well as its dependency, the Adafruit Unified Sensor library - if you've not done this before, Adafruit has an excellent walk-through. With the libraries installed, we can run another quick test sketch like we did for the LCD: open File->Examples->DHT->DHTtester and uncomment this line (15 at the time of writing) by removing the leading forward slashes:
#define DHTTYPE DHT11 // DHT 11
then comment out this line (16) by prefixing it with two forward slashes:
//#define DHTTYPE DHT22 // DHT 22 (AM2302), AM2321
and give it a quick Compile. If you run it, chances are you won't see the expected output on the serial monitor, but as long as it compiled OK, we should be good for now.
After confirming all is well with the basic hardware, it's time to go large! The first step in using the BigNums2x2 library is...well...getting your hands on the library! Like the other libraries that we installed via the Library Manager, we can simply search for "bignums" to locate and install it:
The library comes with two nice examples, which are worth a quick try, like we did with the previous libraries, in order to ensure everything is working. Load File->Examples->BigNums2x2->BigNums2x2FontDemo, and like we did with the basic LCD example, update the pins to:
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
then Compile and Upload to get a feel for the available fonts and how they work. File->Examples->BigNums2x2->BigNums2x2LocDemo is also worth a quick try in order to understand how the positioning functionality works.
Now it's as simple as combining the DHT11 and BigNums2x2 examples to create our own big numeric thermometer remix! Create a new sketch, and add the header portions of each, including the library includes, as follows:
In setup(), we need to initialize the LCD, and DHT:
Then in the never-ending loop(), we just read the temperature value and output it to the LCD via BigNums, over and over, with a 2 second (2000ms) delay between each run:
Now that we have our temperature values outputting via BigNums2x2, let's get a little fancy. The numeric value alone is useful if you're completely familiar with the context (and you probably are, since you wrote the code!), but most temperatures will indicate which scale they are using in order to eliminate ambiguity. Although we're using BigNums, there's nothing stopping us from using plain ol' LCD characters alongside their chonkier sistren, so let's add a small °F legend to the right of our temperature value. To do this, we'll shift the position of our BigNums two to the left, plus use (char)223 in order to tell lcd.print that we want to use the ° character; replace bigNum.print(f); with the following 5 lines:
Behold, a pretty decent-looking thermometer, which can easily be viewed across a room:
If Celsius is more your thing, just swap dht.readTemperature(true) to false, and the F character to C. Or you could get really fancy and cycle between the two, or add a button to toggle them, or calculate the heat index with computeHeatIndex(), or ... well, let us know what crazy things you come up with in the comments below!
Alrighty! We're onto our last installment (for now). Are you have buyer's remorse yet? Are you wondering exactly where your $7k plus $2k yearly maintenance fees are going? Are you ready to kick whoever thinks getting images onto circuit boards isn't necessary or important? Me too!
Saving Your Image for the Future
Now that you have a really nice image in Altium using Method 1 or Method 2, you may want to save it to use it again, especially if the image happens to be a logo! There are 2 ways you can go about this.
That about wraps it up. There used to be some script that imported logos into Altium as a bitmap, but I never had very good results with it and am not sure it's still supported.
Got yet another way of creating a logo or image in Altium? Let us know in the comments!