Rust Programming Language Rust Linz, 25 Oct 2022

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From YouTube: Rustberry Pi: Baby-steps in Embedded Rust - Lisa Passing - Rust Linz, September 2022

Description

One of Rust's biggest draws is the promise of easily writing and compiling code for embedded devices. But where do you start with embedded development when you have zero clue and just want to dip your toes in some physical computing? This is just the talk for you! We'll use a Raspberry Pi and will write some Rust to interact with the real world.

Lisa is a Berlin-based creative technologist, artist, and researcher. Her main obsessions are playful interactions with computers and creative uses of civic tech and data.

Resources:
From 0 to no_std in one session: https://www.youtube.com/watch?v=Pu4MZmB0E28
The Discovery Book: https://docs.rust-embedded.org/discovery/
Embedded Rust Documentation: https://docs.rust-embedded.org/book/

Rust Linz: https://rust-linz.at
Speak at Rust Linz: https://sessionize.com/rust-linz
Twitter: https://twitter.com/rustlinz

A

If you're ready to go, thank.

B

You, oh my god, um it's a nice to be here hello and welcome um just off the bed. I had several technical issues last night, and just until now so um I will hope for the best uh fingers crossed. But if things don't um don't work out quite as well as they should believe me, they did at some point um okay, uh but this is the fun of it right. uh This is Raspberry Pi, baby steps and embedded rust.

B

So, like really tiny dipping your feet into this, if you've never touched this thing before, but um yeah I don't want to actually like talk too much because I'm gonna talk about this. A lot who am I um a couple of people who saw me yesterday will know that what comes next I'm Lisa I'm, a creative technologist based in Berlin, a creative technologist means that I like playing with technology, the fun stuff and trying to use it for artistic purposes or sometimes also useful things, and ideally combining the two.

B

um This is a picture of where I took apart, like a little bubble toy that I got for cheap and I hooked it up to an Arduino and then had like fun with bubbles. It was like very popular with people.

B

um I've been around rest in the rust Community since 2016 2017, um where I just like thought it was cool, jumped in head first and sent a proposal into a rust conference. So you heard that your arrest is coming up to see if he's closed, but maybe next time just like propose something, and if you get accepted, you actually have to learn the language.

B

This is how I learned the language um and uh last November I was like very, very happy and like to be given the chance to organize Reston Arts, an online conference where I tried to bring these two worlds together, like in an artistic, playful, interactive, fun, kind of um or like all, these kinds of possibilities plus rest, um because the uh intersection is there.

B

um Artists need tools, uh there's like more and more artists that can program that want to like Express themselves through either programming or just like any sort of technology that they can get their hands on. So this is like very exciting to me and also to other people, um and this was really cool, so this was me um but embedded who this um I I still remember like the first time.

B

Somebody was talking to me about embedded development years ago and I was like, but embedded in in what, uh because, like I, couldn't really think about like what? What is this concept, um then again, if uh arrests uh webs like home page, um we see it like as one of the big like areas where rust really shines.

B

Like you know, it's like uh embedded um uh so embedded is about like uh tiny microcontrollers, like various things, so my my big area of it's called expertise um is in the Arduino world, so this is kind of like the hobby, the maker space, so like I, don't I, don't build production things I, don't actually have to program machines that then build things like cars or whatever tiny else.

B

um um Machines built these days machines to build more machines, um but like this is kind of like my, where I come from, where I learned a lot about electronics and like this kind of um like yeah I, was dealing with in this space.

B

um If you've like looked into like maybe rust and embedded you've, maybe come across this thing, because the new rust embedded guide um actually recommends the micro bit, um which is like actually an educational board. So for it's meant like to be cheap and like kind of it's, it's very nicely designed and already has some components on it that you can play with.

B

It's meant to teach people, programming and I'm like really happy that um the the rest embedded book kind of like or the embedded Community picked this one up to like um teach people embedded rest and actually only like uh recently discovered it because the first time I looked into the guide. They were still recommending this one um like a more I guess, hardcore board like developer board with like oh it has all these things and like uh and I'm like uh I, don't even like I'm a visual person. So it's like.

B

Oh, the website was like where you can order it. It's already kind of I, don't really know if I clicked the right thing here and do I need something else. What do I need. um So this was scary and not very beginner friendly, in my opinion, sorry, for touching the microphone.

B

um This is much much nicer, so I'm happy they're going this route, um but in the end, there's not just like these microcontrollers, like tiny, like single board things, um but there's also like single board.

B

Computers like where the Entire Computer lives on a single board, you've probably heard of the Raspberry Pi, it's very popular, um even though they're now getting really expensive because, like of production issues that probably people are aware of, um but the cool thing is that or like not the cool thing, but the thing is: if you want to get into embedded, you kind of you need some sort of hardware um to play with it. There's emulators, but I think the fun is actually getting this tangible feeling of I'm programming but I'm programming.

B

The hardware there's something there um and I always go with like use. What you already have, because I have a feeling that most people who program had have at one point in their life, been given or gifted some form of Arduino or Raspberry Pi, or they kind of like lie around and they accumulate.

B

um So maybe, if you don't have one, maybe ask a friend, they probably have one, um because even I had one and I've never really done anything um with it. So the one that I had at home is the Raspberry Pi model air best way, Pi 3, Model, B um it sits up here. I will show it to the camera in the Stream in a second, so I thought: okay, I know a little bit about rest.

B

I have the single board computer. That apparently, is also able to run rust and we can like do something with it. um So let's do something with it.

B

um Just like this is my the point where I'm starting I have super little experience. An actual bare metal programming come from like web development and like higher level languages and like um if there weren't so much Arduino related resources on YouTube and the entire internet. I, probably would not have been able to build anything at this point, so I'm, very, very reliant on like things that other people put out there.

B

So thank you, people who put stuff out there for me to learn it's very cool um so like yeah little experience not really sure what I'm doing but I have a rough idea of how they actually want, um and this is the motivating factor because, like once, you know that you want to build something, and you know it's kind of within your range of expertise. Maybe um you can get there, it might be rough, but you can get there.

B

um What do I want? um So for me, what I? What I really really want is um physical Computing, uh which is also sometimes um yeah, grew up together in like a part of like a creative, creative coding. So what we want is reading from and interacting with the physical world So reading from could be collecting of data through sensors. Some kind of like modules, there's like tons of stuff out there and interacting with the physical world, has basically then not like taking information in, but then after we did something with it.

B

We want to influence the world through our code and this can be lighting up an LED which is already pretty cool, because lots of LEDs make lots of cool um uh lights and, like various patterns, it can be really beautiful, but just um creating a little bit of light, but we can also like actually interact or like um yeah move the world through, like Motors and like different kinds of Motors.

B

That I'm also going to talk about really quickly um and then have an impact and actually have our code um magically robotically um do things in the world, so this is really. uh You can probably see that I'm really into this. So this is what I want to do um for this uh to work. I had to book for a couple of steps that I actually had to do today again for technical reasons and bad preparation reasons.

B

um So if you want to do this, you um can go one of two routes um you can develop on the device, so um the Raspberry Pi is a complete computer. If you like, if you have no idea it's a complete computer, um you can put in an operating system on it. uh The classic one is raspbian. Os, which is like a version of Debian, um you put it on SD card with the SD card, and then you have like a little yeah.

B

It's an operating system, just like you used to um you, can use the GUI or to extend the browser to install rust, just like you're used to on your laptop or desktop um it's really. Nice uh I, also link to like these slides will be online later.

B

I also linked a video tutorial where, like someone walks you through all of these steps, um um and then you can just SSH into the Raspberry Pi, so like I'm, actually doing the same here, I hope the network um will not shut down and, like I, lose connection, because that would be bad.

B

um But then you can actually like SSH into the into the pie and then like run your rust, compile your best write. Your rest there. If you want um the other option, is also cool because it like also highlights one of rust's um kind of like strengths in a way is that you can cross compile.

B

So you can actually write all the code on your laptop and then compile it to a target for the recipe Pi um with the rest of Target ad So, like um if you've never like, if the only Target that I ever added additionally was the wasn't Target so like actually adding another one for a microcontroller or follow like a um like. An ARM device will actually also kind of cool to me. I also um linked to an article where someone actually built like a little like deploy, cross-compile setup.

B

That is also like really nice, so um lots of fun to be had um for this. One uh like for the rest of the presentation. I would actually be working on the pie um because yesterday, when we like this little laptop here had um kind of like some performance problems with like streaming and then also compiling so I hope when I do the compilation on the board, where I also pre-compiled things we don't have to work for a bird, uh don't have to wait for forever to get results.

B

Cool lots of talking um next step is getting to know the pie a little bit, especially these little um yeah. What could be like? A nice word for them, pointy things um uh these are called gpios, general purpose, input, output, pins um and, if you've never like touched anything like this, it might look like kind of weird like what is the purpose of this.

B

But this is actually the coolest part about the pie, in my opinion, um because through these little pins we can like we can connect them to our, like our circuits to the sensors model modules Motors, whatever we have and read and write from them, general purpose input output.

B

um So this is what we're focusing on um it's kind of like putting little wires on these pins um and then connecting them to our circuits.

B

The thing that I didn't know because it's different in the Arduino world is that um there's different kinds of numberings for these pins um or like these pins, have like certain numbers in software that they don't that don't really match with like how you would go and count the pins if you're. If you just look at it- and you would be going. Oh, like you look at this, where I'm going okay like one two, three, four or maybe you go like per um per column, and it is not like this.

B

It has these special kind of names, which is why I recommend um looking at these kinds of like sheets on the internet of saying, like Okay. What are these actually called um because the first time I tried? This is like okay, um we'll see this later, when we connect these. That I was like it's not very intuitive and you kind of need to know what you're doing also, which I also later learned, is that special pins have special functionality on the pi.

B

You see at the bottom here um different kind of like product like serial protocols that you can speak like i2c and um you art, I, guess I, don't know how to pronounce them. um That might be interesting to you.

B

um We will actually use one that is not explicitly labeled here.

B

um The pwm pin, um but just be aware that like if, if you read some of these words somewhere, it's like it's protocols to like talk to several peripherals if you want, um but the this is not important to know right now, but maybe in your future.

B

um The other really important thing to like just quickly brush on basic Electronics is the power and ground. So when we build a circuit in a second, we always want to like um we need to power like we need to get a power from somewhere and we need to like also basically close, our circuit, like our circular Thing, by like connecting it to ground again.

B

So throughout these pins, we have several ground um uh pins that basically all do the same thing like give us access to a shared ground that um that we can use to like close our circuit.

B

um In my example, here, I actually have a breadboard where I like pinned this out, but I will go over this again, but basically now red means where the current comes from, and then it like goes into the ground. And then we like attach things basically in between to do things.

B

I hope like no, like actual physics, teacher watches me explain this, because this is probably really horrible.

B

um Okay, uh so we know a little bit about the hardware we kind of know in the direction we want to go um where's the Rust part in this um because I don't know how to like actually work with like uh registers and like how these two, um how things work like I, will also look forward to Tim's talk later because I'm pretty sure I will learn a couple more things about some of the concepts here. um But luckily there's people out there who've been busy writing cool libraries that we can use.

B

um I've been working with the RP pal um I think if it is like my pal in the Raspberry Pi World um crates, so they're Raspberry Pi peripheral access Library.

B

um This is a screenshot from from the crates IO page, but we can already see that um we have all our favorite words here again: gpio i2c pwm, which I briefly mentioned, which is also going to use SPI uart. So it's like oh yeah, lots of things that we can use.

B

um Maybe later we will only do a couple today, but I think this is actually like, um like for my little research, the library or the crate. That was the easiest to use and just worked so my recommendation for this kind of endeavor, okay, um some electrical components that uh I will use and also quickly talk about when we see them um is that I have a breadboard.

B

It basically like helps me put together my little circuit and some jumper cables resistors um so like cables, are just cables, resistors help um uh not just but regulate the current for some of the components, for example, LEDs might not um or might break if there's too much current in the circuit so like you might want to put a resistor in front of it just to like Shield your components a little bit.

B

We have buttons or switches for interaction um and Motors, or servers or steppers like different kinds of Motors, basically to do to do cool things in our little projects. If these words mean nothing to you right now, I will show them to you. No worries, okay, um so step one. So this is all the prep work done.

B

It's like time to breathe, um and then we start with step one in in our Endeavor of like okay, somehow interacting with this thing and I called it hello, Blinky world, because the I learned that in in the world of hardware um the hello world is making an LED blink, um this is kind of like the same thing and I thought it was really nice. uh Rp pal actually has the blinking light.

B

Example in the readme and so I thought: okay, let's just take this code and try to run it and make an LED blink and I will attempt this. Actually, let's see uh so this is the wind. ah Actually, let's do it differently, because I don't think I'm I ran into several problems and I had to like quickly.

C

Let's do it like this.

B

I think I would show you the code, that's on my laptop and then uh run the code on the pi, because I don't think I have an editor on the pi. That is not the default one and I don't want to use that.

B

Yes, trust. All the authors.

C

B

So this repository is also online on on GitHub, together with the slides. So you can like look at this if you want um I also want to like include more information about like about the pin connection, because that's not really good right now feel free to ping me. If you want to do this and you don't or you get stuck with this, but okay um with that being said, is this big enough? Yeah I think so.

B

um This is basically the example from the RP pal readme, except that I replaced the error type with, like the dynamic error thingy with anyhow result, but they don't have to worry about this.

B

um The cool part here is that we just can use some like standard Library stuff like threat and um like time, components or like time functionality, um and then we get from our people just um gpio gpio, so the base um the base type to interact with our gpio pins, uh and then we say here- and this is already kind of like the thing um we create a constant with the actual pin that we want to interact with, in this case it's 23, and this corresponds to gpio 23 in the diagram or in the thing that I showed you and not the physical thing.

B

So it's really the the gpio um notation for this and in the main function um we just print some device info from device info, which is nice.

B

um But then the actual thing happens here we create a new gpio PIN um and then we, it's part of the API, say, get this specific pin that we want to talk to, and then we want to convert it into like basically saying that there should be an output, because we have to be explicit about.

B

um Do we want to use a certain pin for input or output default is usually input. So if we want to like write to it or like output, something we have to like, say hey. This pin should be an output pin now and then example uses a simple loop loop statement and we have a actually a pretty nice function that is called pin toggle. So we have two states um on on or off or let's say, high and low, which is usually what it's used in the in the hardware world.

B

So we want to say where low is zero or like false um and high is true, basically so whatever it was before we talked between these two and then we sleep for a little bit and then we do the same thing again, which will result in a blinking LED, exciting.

B

Okay, I will actually go to this. So this is on the pie and I was um I, hoping I'm still here. It's not responding. Yes, okay, so I ran this and now I will switch to this camera, which is this one yeah. Does it work cool?

B

So I have my setup over here and I hope this works. So this is the pie whoop. Oh.

C

B

I need a higher resolution. Camera I think um so this is the pie. Maybe let's put it like this because like this is how you saw it in the diagram.

B

That would be amazing.

B

Okay, thank you Stefan ah amazing, just oh, my God, it is very blurry. I am sorry. um The important part is I tried to stick to the color coding. uh If my cable is permitted it so red is positive. Black is.

B

How many people does it take um no 15., okay, um red is the Positive Black is ground and then for this example. um The blue cable is actually the LED and if you follow it all the way here, Stefan can you move perfect.

B

um We see that I'm here on my little breadboard, just a little explanation for this um here on the sides. We have the blue and the red line. That is indicated, which we can use to say like basically I feed the ground Into, the Blue Line, which gives me access to ground in the entire line.

B

um Same goes for the red line, for the positive current, so like I can I can access the entire positivity like the the positive current from there.

B

um So what I did then is I branched out so where the blue cable goes like all the middle parts, so on the sides it goes from top to bottom and on the sides, basically each they go by row, which is something that is also like randomly or seldomly explained.

B

um So the blue cable goes into this round, which is I, think labeled six. But you can't read this here, um which shares the um which a chance with the LED and then the other leg of the LED goes into row row: eight, where I put the resistor. So this is what a resistor looks like and the other leg of the resistor goes into grounds.

B

So if we follow the curve like the the circle of the circuit, we go in here positive and then throughout this route, through the LED, um through the resistor and back into ground. What's the use of the blue cable? Now this is where we now say from the pie. Write High current into this um because, like actually, if you've paid attention and I didn't say it that in this circuit we don't actually use the red cable yet um so the positive current in this example actually comes from the positive current actually comes from the blue.

B

Cable ah I was talking too fast for my own good um comes from the blue cable. It goes into here. So every time we write like the toggle, we write either high or low like give current or not, um and then we wait, half a second uh and depending on which state we're in the LED is blinking and then blinking, hooray cool. Thank you. Stefan.

B

B

You get a better setup.

B

B

um So, with the blinking LED, we have like step one um resolve. We could like write a little bit of something into into the world and, um first of all make sure that we can actually talk to our gpio, pins um and second of all, be like uh yeah did our first thing in the real world. Amazing um yeah. This is the diagram again, um here's the connection again, so this is all documented, at least in the slides.

B

If you want to do this again um and we ran it cool um step, two hello touchy world, uh so we we wrote something out into the world, but it's also I talked about like reading from from the world, so like kind of interacting like we need to interact with something um and I chose touch because, like I have this like touch sensor?

B

That I can also show you in a second, um and there was another thing that I stumbled upon coming from Arduino, because the um standard Arduino Uno board that you have has digital as well as analog pins and what's the difference um is that in the physical world, um binaries actually don't exist. So everything is um an analog signal or like it.

B

It has various it's a range of things, so when we say um it's either like we write the um to the LED and either say high or low, what we mean is we we go to the extremes of the ends of this current, to make sure that we get a clearly discernible State, um but in reality we can like.

B

We could adjust this, and we sometimes see this because you can dim light based on the current that you send through a thing, um and the thing is that um um this, the Arduino owner can read analog Earth um analog signals, analog inputs so like we can actually like um get all this like finer grain information, um but the standard Raspberry Pi can actually not it has only digital, pins and I didn't know this beforehand. I was like okay.

B

This kind of is annoying because a lot of the easy to use sensors that I wanted to use actually rely on on analog signals and inputs, um so I was kind of like okay, maybe I do use like a simple button, but then I realized that other um this touch module that I have is basically what it does is.

B

um Even though it's an it's an analog module, let's say that if you touch it and you basically close the current and if you don't touch it um like, if you touch it yeah you close, the circuit I mean, and if you don't touch it, um the circuit is kind of interrupted and even though it's an it's an it's supposed to be an analog module I still get the two states, so it could kind of like hack around this by saying, okay.

B

This is enough for me to um to actually work with this, um and I actually also have to keep an eye on time anyway. uh Okay, so to go the next step. um Reading from a touch sensor, uh I connected the the ground and the voltage as we had before a touch sensor has three pins, um so we go into voltage and ground, and then we have the signal that we can so that we can read from it.

B

um I put it into GPO 24, so like next to the LED, so I can, for this example, use everything.

B

um I will quickly look at the code for this one because um yeah and it's um uh similar in a way, um as opposed to like the the LED, so we still get the gpio pin um I called into input, which I think is optional in this case, um but just to be explicit that, like this, is an input um and then I wrote another loop where basically I want to say or like read um from this pin if it is High.

B

um So if, if someone, if it's getting touched, um I want to print hi and if it's not getting touched like there's, no, no connection, it should print low, um and then we sleep for a little bit in between, so that we don't like spam, our like we're going to spam our terminal anyway, um but not so much okay. So let's run touch it. Should it prints, low okay? So this this is working um and I, don't know if you can switch the camera over uh to this camera yeah.

B

Yeah, it's going okay, um so this is the um touch module. It's really just like a little square.

B

To see if I made a stupid mistake.

C

No, but this should open okay.

B

Okay, maybe let's not use too much time on it. It was then part of my technical mishap um from earlier believe me that it does or like it did actually work at some point, um but like I want to uh uh get moving to like not take too much time and like also get to the big finale, um because there's the three uh as well, because like um reading to like uh sending stuff out into the world like an LED, is cool um but I.

B

Think it's super actually like super duper interesting if we actually start playing with motors because they have so much potential and you can build a lot of stuff with them um and for this example, I actually brought a server with me, which is I'll, show you in a second it's a tiny motor that is actually like, quite sophisticated in a way um because we can control exactly um in which position it. It should move um with just code in this part of like method of of telling the server.

B

What how to do that is called pwm or pulse width modulation, um and what we're actually doing is that, like in certain intervals, um which are indicated like always when like when we start sending a pulse, um so this like in in certain intervals, we send a signal for a certain length and based on the length of the signal the server then understands in which which position um it should move to.

B

uh If this is a little abstract, it will hopefully be clearer in a second um just like for these tiny, cheap, like hobby servers that you get the the range is usually that it can move like from zero to like a 180 degree angle, so they're kind of like a half circle.

B

um There are also like now servos that can do a full like 360, so if you're one something specifically like this um look out for it in the shop but like usually, this is like the 180 degree angle is what you, what you usually get. If you get like the the standard average server, they usually also come in packs of five like they're, really affordable.

B

Okay, the circuit for the server is a little bit more, uh like only actually like a tiny bit more um elaborate, um let's say um for some reason, the cable the servo comes with um the VCC is also indicated in red. Ground is brown and not black for some reason. But now you know, um and then another note that I wrote really is like tinyly in here. Is that um uh usually, if you have a motor like they can also be like really really big and powerful.

B

You should separate the power supply from your motor from like the rest of the circuit and like the um uh yeah of the components that you work with, because when the model starts working, it draws a lot of current, which can kind of like uh lead to like really like gaps or like uh disrupt like the rest of the circuit, and you kind of like want the stability. So you should separate this um for this little example. Here.

B

It's fine, but if you want to like do something with like a big motor that pulls something you probably want like an extent like a different different supply for that um yeah, and then we connect the pulse, which is the third, um the third pin on the servo uh to the um to the recipe.

B

um There's another thing that I didn't know and it gets you. Our people gives you an error that I didn't really couldn't really connect from what was happening to what the issue was um is that the Raspberry Pi provides Hardware accelerated, pulse width, modulation, which is really like, accurate and fast and cool, but you have to enable it first, but there's actually a section in the RP pal um documentation. That tells you how to do that. So that's! If you get like a I, think it's I think it's just permission.

B

Denied and I was like what kind of permission um this might be related to this. Okay, uh quick, let's run through the code so that we can get to the finale.

B

um The biggest difference is that in that, um instead of gpio, we now get a pwm, and then we get channel polarity and pwm from that, and these constants are important and because they depend on the kind of Servo that you have. So these are the the units for the standard, like the little blue server that you see in the second, um where the the period in milliseconds like this. This value is kind of like the the frequency in which we send the pulse um and then yeah.

B

We can kind of deal with that neutral position, but like this is basically the the length of the the pulse signals um that we then say like that. Give us the position of the servo, so the minimum pulse length is 500, it's not merely. It might be. Microseconds here actually I'm, not sure, um and then two this would be zero angle um and then the max is um 2500 microseconds um to get to the um 180 degree position.

B

Okay, now that we know that we can go to Main and initiate our pwm with period where we put in all this information um I from microseconds and then the the the period is in milliseconds.

B

um What polarity means in this case I am not sure, um but I just put it in from the example, so it works. um So what happens is that we initialize this. We sleep for half a second and then I, say: hey, um send a different pulse so like set pulse width, and then we move to the minimum, select the zero angle. Then we sleep again and then we do this little Loop.

B

That basically says oh then walk to like for minimum walk to the neutral position um in like small steps, so it looks like it's. A little rotating and I will actually not status right now.

B

Can we also get the camera on the setup again cool?

B

um So this is a little Servo um they're, usually like very small, and they also come with different kinds of um these little things to put on top different kind of arrows. So I use this one because it like clearly indicates like where we're going here. Yep.

A

C

Don't see it, no, oh gosh! Well, let's do it like.

A

Just to take the screen, yes, okay and then anything just show again. The okay.

B

Let's do it like this? Okay, this is the servo cool, it's very small, um there's all the logic and all the electronics are actually inside this little thingy. um You see the cables coming out. uh I placed the important cable that sends the pulse in what now it detached it. Damn it not good put it on here um and then uh I will try to run the code and like hold this, and you can see what's happening so remember. It will like walk through the positions uh automatically.

B

Oh, my God I will never do this again. It's too much.

B

Did you see it should I? Do it again, yeah, okay,.

B

So we start with the neck. Yes, and so we started with neck position, then switch to to minimum and then, like we iterated over the top, we have everything now so the the only thing that's missing really is a creative idea with like what to do with this stuff and I'm, probably way over time. I'm. Very sorry, um but I don't know if I have a slide for this section, let's see bring everything together.

B

Okay, let's do this, so I need to do a little bit of rearrangement, because I only have one Raspberry Pi with me, so I will quickly unplug all of these and then build up this.

C

This piece here.

C

C

Yes, I am sorry.

C

C

C

uh We can do questions while I do this, but only easy questions, so they don't.

B

Have to think too hard foreign.

C

B

Is enough um to move, but it will um like it kind of requires, like the the frequency you have to keep up the frequency anyway right so like we can. We change the pulse once, but the what pulse is actually constant. So it's not actually to what I said. First, we need the constant pulse, but then we keep it at the same value to for them.

C

uh One two three one, two three here.

C

And this should be um here.

C

And this is one two three here: oh my God.

C

Where does this one go right here.

C

I believe this one goes here.

B

uh uh Stefan, it's in my notebook there. No, oh! It is in the front actually perfect. Where I put my little cheat note in case I, forget everything.

C

um This is the circle: okay,.

A

Yes, then I can keep.

C

You a few minutes. Thank you. Why.

A

Lisa is preparing the rest of her demo. uh I have a um a surprise for you. uh I hope you will like it. I asked the grand garage people to do something for us because we're here in a maker space, and so we have something for you and I will try to show it to you here. I can see it. Can you see it? Can you see it? Can you see it? So you will get your very own special laser cutted, rust logo, with the lint sting and so on so I hope it will.

A

It will come out of the laser cutter in time. I have one and we get 20 of them, so everybody who is here should get one I'm I hope it will be done in a second, oh.

A

B

Cool uh I'm also almost done um I only slightly confused myself.

C

C

C

C

B

Okay, this should work.

C

uh Hopefully, that's good.

C

Work yesterday.

B

Okay, let's go with.

C

This I will hold this like this. Maybe we can even do it.

B

Very professional of me, okay, um so I built a little game um with this. It's a complete Hardware game um and I build a beautiful interface out of cardboard um and a little bit of gaffa tape.

B

It travels very lightly, it's nice, um so the idea is that you're kind of like trying to to crack um into a vault or something- and you have to like guess um three random numbers uh in sequence and if you indicate it, as indicated by the three blue lights at the top, um the Servo arm will kind of uh move from zero to 180 and in the background, every time it is close to the randomly generated number um that we don't know.

B

The yellow LED will give us an indication of like oh we're close and then, if we're close, we need to tap the touch sensor and if we're fast enough, we basically correct the code and then once we have all three numbers we get the light show.

B

um My only worry is that the touch sensor might not play well with us right now, but let's see how it goes.

C

And let's play it, hopefully, oh damn it.

B

I called it Panzer knuckle and I couldn't write.

C

B

Okay, wrong window: okay, so what happened in the beginning? If that you maybe heard it is that it did a little configuration um and I also did uh the LEDs are in the wrong order. But this is fine and you can see um you can see the servo just like ticking through the individual steps like one by one and once we get close to the secretly generated number in the uh in the code. We ah no. No, it didn't.

B

This might not be the case that I just don't get the correct, touch signal or was just too slow or there's a bug in the code. Anyway, uh let's see.

B

Okay, something happened that wasn't supposed to happen, but this is the idea of the light show. In the end, um it was like a quick example of just like throw everything together. um You can play it later. Maybe when it's not live it will work magically much more reliably, um but just to give you an idea of the code.

B

um How does this work let's go through and all together made a little game, States drug, to keep um the data in place.

B

um We have like yeah, also like a little state, so we have like this little setup configuration then the actual play Loop and then the win and the place with the um just links all the LEDs. We have a lot of setup code, um then we have a little bit random number generation um setting everything up and then actually the the loop that I'm using with this just like matching on the states.

B

So, instead that we set everything to low and sleep and then do a little server movement just to see if everything works um and then in play, um I'm actually like uh matching on like the the current LED, is kind of like indicating which, which state are we in right now so like? If all LEDs are like blinking like they're all like High?

B

um This is kind of like the indication that we actually won.

B

um This is the matching on the current number that just like use a little bit of wiggle room with, like the actual number, because, like we can't actually be that precise with the with the movement.

B

um But basically once you, you match the number. We generate a new one and then like start linking another part of like the next LED, uh and that's like a little bit of logic to make the server move in One Direction until it hits maximum and then like move it in the actual in the other direction, um and then the code for the light show- and this is it it's not that much.

B

um It's also not that pretty maybe, but it like, gets you um there to make a little Hardware game um and that's fun to make like in a little box and just put a cable in there, and then people can play it. um This is it I'm, so I'm so excited.

B

um So this was baby steps like just like, mostly dealing with electronics and minimal part on the rust embedded side, um but I think it's a super nice way to like just ease into, because we can write code um as we're used to in like a not embedded environment and just like go from there.

B

I put up a couple of um videos, especially the one by uh macroman who's like I, think it was like a wrestling session, maybe um uh where he goes from like zero to um no standards like actually going a fully bare metal um so like. If this is more like the the way you want to go um check out this video and then I can only say Vietnam and then finally stop talking and thank you very much.