Tod Kurt Part 2

Welcome to the CircuitPython Show. I'm your host, Paul Cutler. This episode I'm joined

by Tod Kurt. Tod is a co-founder of ThingM, a ubiquitous computing and Internet of Things

device studio based in Pasadena in San Francisco. He is creator of the popular BlinkOne USB

notification light in BlinkM, the smart LED prototyping device. Tod is a co-founder of

the Los Angeles hackerspace Crashspace, the author of the book Hacking Roomba, and an

active member in the CircuitPython community with his CircuitPython Tricks webpage. Tod,

welcome back to the show. Hi, thanks for having me again. This is great. I used to listen

to a podcast that when they had a repeat guest, they would officially become a friend of the

show. I'd like to welcome you as my first official friend of the show. Thank you. I

feel very honored. It's been almost two years since we first chatted and way back in Season

One. And one of the big things that's changed in CircuitPython since you were last on the

show is the addition of Synth.io. This past August, we were on a panel together where

we discussed Synth.io. And I'll link to that in the show notes for anyone who wants to

do a deep dive into Synth.io. But really briefly, what is Synth.io in CircuitPython? Yeah,

that was CircuitPython Day. That was a great sort of constructed holiday. It's a great

time period now. But Synth.io is a synthesis, an audio synthesis, musical synthesis library,

core module, I should say, in CircuitPython. And in CircuitPython, core modules are things

that are built into CircuitPython. They're written in C usually. And it means you don't

have to do anything. It's just there. And it's incredible. It's polyphonic. It's got

filters. It can do arbitrary waveforms. It's got LFOs and modulators. Pretty much all the

things you would want in a synthesizer, it's got. And I've been having lots of fun with

it since it was in a pull request in like January, February. Yeah, you've put together

a tips and trick page for Synth.io, just like you did for CircuitPython. And you've also

designed a couple of boards to take advantage of Synth.io. Tell me about some of the boards

that you've worked on. Oh, sure. Yeah. So I've designed a whole ton of boards, like

the ones that are kind of useful. I usually do an extra run and put the remainders up

on my Tindy store. So people that want to get those, they can get them there. I sort

of have two main interests in these boards. One is to make the sort of really easy to

build learning platforms that people with like a QDPI or a Raspberry Pi Pico can just

drop it down, add a few extra other easy to add parts. And they've got a little synthesizer

board, and they can like write their own synthesizers. I've not been working too hard and making

a fully fledged thing for these kinds of boards because I think of it more as a, for me, it's

like an experimentation platform, though that like, you know, some other, like, like these

Arduino experimenter kits from, you know, several years ago. And the other, the other

kind of focus I've been on are what's the thinnest circuit board microcontroller, sorry,

circuit board synthesizer MIDI controller that I can make because I have often carried

a little MIDI controller or a little synthesizer gizmo in my backpack or my book bag. And,

you know, I don't want it to get damaged. So I don't want knobs sticking out. I don't

want things, I don't want to be a bare circuit board. And so a lot of my stuff has been like,

that's the thinnest thing I can do. And so on my tiddie store, there's a couple of examples

of these very thin MIDI controllers. And the most recent one has been this fully enclosed

little cap touch synthesizer that I had 50 built that I gave out as to the 50 attendees

of our sketching and hardware conference that happened a couple months ago, because there's

a bunch of friends that I know for like the last almost 20 years, and I wanted to infect

them with synthesizers.

And what was their reaction to it?

I think I think a lot of them are pretty good. Of course, now we're all old enough that a

lot of them have kids, so they kind of gave them off to their kids. But I should be having

I should be having a version of that board up on the tiddie store as well. It's um, it's

basically you know, what is it a octave and a half cap touch keyboard with a couple of

modifier keys. It's got some reverse mount LEDs to let you know when you're touching

the pads. And then a couple of examples synthesizers that you can install onto it like one's a

wavetable synthesizer that makes really weird, cool, like space noises. And another is a

drum machine. And I'm hoping that I'm going to do a bit more and get a little bit more

interesting examples up there that are like kind of full synthesizers because I think

you can do a lot with this little platform and it's like, no parts that stick up. So

you can just like slide it in like you would a pencil case into your bag. And it'll be

safe.

That's cool. Last year on our old podcast, the bootloader you shared your experience

attending Hackaday Supercon. You were there this year too, just a couple of weeks ago.

What were some of your of your favorite talks at Supercon?

Yeah, Supercon is really great. Have you like you should come some year.

I should I really should.

Like you and me, we only know each other online. We don't we've not been in the same physical

room in the same place. We've been in the same Discord channel tons of times. Right.

And so there are so many people that I know in the larger sort of hardware hacking community

that I only know in this way. And Supercon has been the one of the few cases where I

get to meet some of these people, you know, and so like one of the cool things is, is

like a geek mom who Deborah Ansell, she lives in Los Angeles. And so I've seen her a few

times in reality. But she has a small business with Ben Henke, I think, and Jason Koons.

I think we covered them, their product, the LuxeLavier in one of our bootloader podcasts.

We did.

And so Jason Koon, he makes these beautiful pieces of LED art that fit in the palm of

your hand. These little like they're not grids of LEDs. They're like a Fibonacci spiral of

LEDs. And they just are jewels. It's like and because he uses such small LEDs, these

little like one millimeter by one millimeter LEDs, but they're like new pixels. The LEDs

become a surface like a sorry, a texture rather than like individual LEDs. It's like it's

just incredible. And so I got to actually meet him and hang out with him and and hold

some of these things in my hand. Just just marvel at them. Like it's it's one thing to

see what see pictures of them on websites. Another thing to actually like, you know,

gaze into it. Right.

And that was as I was just just seeing all these people that I've only only interacted

with on Mastodon or or Discord or whatever is really great.

I know looking looking at Super Con from afar, even some of my former guests have been there,

right? The Flowers was there.

Oh totally.

Castillo was there. You're there.

Oh yeah.

So it's like that gives me a reason to go when I actually know a couple of people already

too. So I so like you said, I have to I have to find a way to get there in the next year

or two.

Yeah. One of the things I noticed hadn't seen before is in some of the talks and some of

the idle conversation, people would just say, oh yeah, and we programmed this with Circuit

Python. Like it was it wasn't it was no longer a special thing. We're like, you know, we're

out of this evangelization phase where it's like, hey, you should try this weird thing

called CircuitPython. It's like now now people are just using it because, oh, it's a good

enough tool and we can use it now to do a lot of the projects that we've done in the

past. And that was really nice that it was just like, oh yeah, it's just another tool.

That's great to hear. Tell me about some of the lightning talks that you attended.

One of the coolest things they did this year was lightning talks. So not everyone not everyone

has the time to like prepare an hour long talk in front of hundreds of people. That's

pretty intimidating. And so during one of the days, they just said, hey, if anybody

wants to give a lightning talk for like 10 minutes, come on up. And maybe you had prepared

slides. I think most people had had to prepare some slides. I think some people didn't didn't

so much, but they were all great. It was like, it was, it was like hour and a half, 10 people.

And it was everything from, you know, Scotty of strange parts talking about his, how his

brain injury led him to whole, whole new hacking experiences to, you know, Allie was up there

with her, her Pokemon ball purse. It was just like a purse, purse Pokemon ball, but it also

is remotely controlled light up Neo pixel craziness to Tina Belmont taught us all how

synthesizers worked from, and she, and she's been doing synthesizers for like over a decade.

So it's like, you know, there's, there's, here's someone who actually knows no sense.

And yeah, it just was every, from all over. It was like one of the best kind of condensed

group of talks and the videos up on YouTube right now because hackaday streamed the, the

super con has sort of two stages, the main stage and the design lab stage and the main

stage they live stream and keep the live streams up for awhile. And so for the time being,

you can go to the youtube.com slash hackaday and click on the live tab and then there's

all the talks from the, from the main stage of the super con so you can, you can get those.

And so that was great. The other one, another one was on the main stage was this hacker

named sprite. I forget his real name. It's like your own maybe. Yeah, I can't. We'll

find it and link to it in the show notes and give them credit. Yeah, yeah. He, he's one

of the, he's one of the, the Uber hackers. He works for, for expressive. He is responsible

for a bunch of the really cool FPGA hacks you might've seen on hackaday. And he continued

that trend with his talk was about taking the old 1982 vector video game system called

vectrix that, you know, back then took cartridges, everything to cartridges and he reverse engineered

how it all worked and then recreated how that worked in an FPGA and to be a, an appropriate

emulation instead of boringly driving a LCD screen, he figured out how to, he found a

little like tiny portable right angle CRT and had an analog stage that drove the CRT

the way that like the real vectrix vector scope did. So it was like an analog output

of these, you know, a very clean lines that that's indicative of a, of a vector scope

output and it is, it was all handheld ran off a battery. It just amazing how these little

car, it would play actual vectrix cartridges, but also would play all of these. There's

apparently there's a vectrix, a demo scene of people making new stuff and he found a

bunch of that and was able to slot in those custom demo scene cartridges and it just was

like this tour de force of engineering. That's so cool. Really brand new stuff. Yeah, really

brand new stuff and FPGAs driving really old stuff of like tiny old CRTs from, from video

phones. Now I gotta ask you about a talk that was about the cuddly companion bots with a

title like that I have to know more. Yeah. So, so Angela Sheehan, she makes this really

interesting sort of snake, not a snake. It's like a fuzzy boa companion bot. So a companion

bot, if you've never heard, is a robot that you have on your person somehow. Usually wear

it kind of on your shoulder or maybe it's kind of like you, it's a slung thing, like

kind of in kind of the way a purse would be or you'd wear, maybe it's a backpack and it's

sort of the, the people who make these call them, call them like you companion robots.

So the way you have maybe a companion animal, I find it fascinating because robots are hard

and they're noisy and they take a lot of power and they are not really amenable to being

so close to a person, but here they are making these devices that, that will sit on their

shoulder and, and have to interact with the more soft human world. You know, that means

that like in the way they move and the way they, they interact with the, with the other

people, with the person that they're, that's, that they're on. So Angela's talk was about

like how to do some of that. And that was, that was, that was really fascinating because

I love robots. I'm not interested in making us, making a companion bot, but all the people

in the bot community are really cool. It's like, it's Angela and Ajay, which, which,

you know, and Allie who's the Pokemon ball thing and geek mom, like as representatives

of the, of the, of the companion bot community, they're just, you know, wonderful. Oh, that's

great. Yeah. Yeah. And, and so, yeah, so it's just a, that, that is, that video is also

up on, on YouTube so you can watch her talk right now too. I mentioned the flowers earlier.

What was her talk on? Oh man. Okay. Star girl, AKA Theo flowers for the last year or so she's

been working on making a web viewer for key CAD schematics and PCBs. You think like, oh,

that's pretty easy. You know, you just read the file format and you just, you know, turn

that into an SVG and no, like her talk was, her talk was hilarious. It should have been

a main stage talk so we could have a video of it right now. It'll like the, they'll upload

the video of it eventually. It was just, just amazing. Cause cause you know, key CAD it's

30 years old, you know, it's, it's this amazingly long lived code base that's been touched by

hundreds of people. And so the fact that it runs as well as it does is amazing. Yeah.

I had no idea that it's been around that long. Yeah. Yeah. It's just, um, I mean, granted

the people that, that wrote most of it, uh, work at CERN, you know, there's some of the

smartest people on the planet. So, but it's, it's like any, any long live long live code

base has a bunch of different ways of doing a single thing because you know, you do it,

you do it one way and then like sometime later you figure out a better way to do it, but

you have to keep the old way because of compatibility issues. And then suddenly it's a couple of

decades later and you've got a couple of piles of legacy stacks you have to deal with. And

so in navigating that to make it so the web viewer works, she had to figure a lot of that

out. Her talk about how she went through it was, was really, was really nerdy and really

fun and really funny. That's pretty cool. Supercon is known for its badges. What was

the badge like this year? I don't know if you've seen pictures of it yet, but it looks

kind of like an old Tektronix scope and these scopes, they had a round CRT screen in like

the top left and then they had these big knobs and buttons that sounded kind of surrounded

it and it was a sort of a vertical orientation of the whole instrument. So like a lot of

the, a lot of the test equipment nowadays has sort of a horizontal orientation with

like the screen to the left and the knobs to the right. This thing was, is vertically

oriented where the screen was kind of the top left and the buttons were on the, on the

bottom. That's kind of what the badge looks like. It has this round LCD and then a bunch

of buttons and some little like connectors on the side. And then when you turn it over,

you see that it's a Raspberry Pi Pico and a couple of support chips and, and it's a

pretty brilliant little hack. There's an arbitrary waveform generator that I think is written,

so the whole thing is running MicroPython. Okay. The way you kind of interact with it

is there's an, there's sort of two parts to the badge. There's the arbitrary waveform

generator that outputs an X and a Y signal. And then there's the scope part that reads

an X and a Y signal. And so you can just use it as an oscilloscope. You can just feed in

an X and a Y and, and then get cool Lissajous vectorscope patterns. Or you can use the arbitrary

waveform generator to give you like an X scanning time base to then be your X and then have,

then your signal, whatever your signal you're measuring is your Y. And then you get like

more of a standard oscilloscope readout where the scan is a constant time and then the vertical

Y axis is showing you what the voltage is over time. And you can do all of that without

doing any code on the badge. You just like, like hook up wires and press a few buttons.

And it's, it's basically like a, like an old oscilloscope. It's all like got green phosphor

look and it's as the traces move, it's got this cool phosphor fade effect. This, it's

like this running is like a separate process on the second core of the RP 2040 that's in

the Pico or something. It's, it's incredible. But of course it's all open and you can hack

it all. And so I was like, I hacked around with a little bit, but I'm not very fast with

MicroPython. So one of the first things I did is they just blew MicroPython away and

so CircuitPython, cause I know how to run these GC nine a zero one round LCDs. I've

been playing with those for a couple of years. So I did, so I did, I did a bunch of little

dumb hacks with that. And then you created a capacitive touch sensor to go along with

it. I sort of, I've been, I've been playing around like, like I mentioned with the boards

that I made, I've been playing around with cap touch buttons for a long time now because

in CircuitPython it's so easy. You just use the touch IO core module that's built in and

you say, Hey, I want to turn this pin into a touch pad and then it'll give you a true

faults value whenever somebody touches the pad. And so it's super simple. But I knew

that there was ways of doing more complex sensors with just a couple of cap touch pins.

And so you can actually make a slider, a capacitive touch slider with just two pins if the pads

are shaped in a certain way so that you get sort of a ratio between the two pins depending

on where your finger touches. And similarly you can make a rotary control, a touch wheel,

sort of like the old iPod touch wheels with just three pins. And so I'm like, and this

is a, this is a thing that's been known for like 20 years or something. I've not played

with it much. I'm like, okay, I'll just, I'll just spin up a quick board and I'll have it

so that the pin out matches the little expansion pin out of the badge. So that in theory you

can just plug it onto the badge and have it work. I got the boards back like two or three

days before SuperCon started up real quick. Went once I got the badge and uh, yeah, it

worked great. I was like so surprised. Yeah. It was like, it was like, you know, 20 lines

of CircuitPython to do the, do the, the, the, the, the simple math to turn the three

sensor readings into a angle. Yeah. So that's up on, on the GitHub. There'll be a link to

it hopefully in the show notes. Absolutely. And I'm working on a board cause cause I'm

so excited now by like, Oh, I can do like various types of interfaces with, with capacitive

touches, not just buttons that I'm working on a little, a sort of cap touch explorer

board that'll have some wheels and some sliders and some other things. See how that turns

out. Now there was some controversy around the lack of diversity in the speaker lineup

at SuperCon this year. Not having been there myself, was it fair criticism? Uh, yeah, yeah.

There's, I mean you can just go to the, go to the, uh, SuperCon website and you'll see

that all the speakers, they're mostly white guys, you know, it's um, there's a Carrie

of Alpen glow has a really good thread on Mastodon about this and cause she, she, she's

been a speaker in the past and she comes every year and she was there this year. But it's

just, it's, it's really hard because when, when a community has sort of a default kind

of member, you know, like, like, like you and me, we're kind of the default kind of

member. We're sort of middle aged white guys. Right. Um, you know, that's, that's, that's,

that's kind of your, your, you know, they're stereotypical hacker and, and when you're that,

it doesn't, it's not hard to get the default to, to submit talk proposal when, when they

just say, Hey, here are talk proposal website is open, submit a talk, you know, cause you

know, we'll have, we feel we, we have the time. We also feel comfortable in submitting

a talk if we can, if we can get over our own personal, like, Oh, I have a fear of public

speaking, but like, but like, but like, but like we mostly feel welcome in the community,

but there are so many other people that are part of the community, but they don't feel

welcome. And you know, usually these are the non non white guys. And so like, how do we

get more of those people that are in the community, but don't feel welcome? How do we welcome

them in? And we really have to do the effort to, to make sure they know they're welcome.

And and that's hard. It's a, it's a proactive reaching out rather than a, than a, Hey, come

submit your talk to us. You have to actually go out and get people. And that's hard.

You're absolutely right. Yeah. It's very hard. And even with the podcast, I'm always trying

to keep that diversity, you know, and inclusion top of mind and making sure that I try and

balance those guests out. And there's been some criticism of the Python podcast ecosystem

as well of not being as diverse as it, as the Python community is. So you're right.

It's something that you have to work on. You have to have it top of mind and you have to

keep working on it and you have to let people know that you're going to be fine. You're

going to do great. And welcome them with open arms. Yeah. It's, it's really hard because

it's a lot of us are introverts. It's hard. It's hard to reach out to people in general,

you know, and just say, just say, Hey, you know, it's like, like, this is the problem

that we had at crash space. The hackerspace that I founded, sorry, co-founded that, you

know, people, people would come in off the street and just say, Hey, is this a hackerspace?

And we'd be like, yeah. And then we would all turn back to whatever project we're working

on. You know, it's like, that's not how, that's not how you welcome new people to welcome

new people. If they come in the door, you have to like get up and, and welcome them

and show them around and say, here's where the laser cutter is. Here's where the 3d printer

is, you know? Exactly. You're absolutely right. But it's, but it's so easy when you're, when

you're in your head, you're, you know, you're focused on a thing and you're like, I just

want to solve my problem. Well, we're almost out of time. And the last question I always

ask is which board do you reach for when starting a new project? And in over two dozen episodes,

you're the only person that's chosen a fun house and an itsy bitsy. Are those still your

go-to picks or is there a different board that you reach for these days? Yeah, probably

these days for, I'd say general CircuitPython work, I would choose a Raspberry Pi Pico because

of the fact that they're sort of sold at cost at $4. They're, they're like a really cheap

way of just trying stuff out and lowering that barrier of fear of like, Oh, what if

I, what if I fry something? What if I burn this board up? It's like, well, you've burned

up $4 if you have. But also like the, the space of things you can do with a Raspberry

Pi Pico is really, is really large. And so it's a really great board. Even if you're

not doing CircuitPython, like you can do a lot of really great stuff in Arduino. You

can use the Pico SDK to get really low level. It's got that PIO functionality that's sort

of like a little bit of programmable logic inside of the Pico that you can, you do to

do, do like really fast protocol type stuff. And so it's, it's a very interesting board.

You can do the PIO stuff in CircuitPython even, which is amazing, but it doesn't have

wifi and there's the Pico W that has wifi. But I think, I think that the, an ESP 32 board

would be better if you want to do wifi. And for, for, for wifi CircuitPython, I like

something, I'd probably recommend an S3 board. Yeah. Yeah. ESP 32 S3. And then like which

one? So like, like my default is a, a QDPI ESP 32 S3, but I think wifi devices need some

sort of a display because there's this whole onboarding problem of how do you get it onto

your net? And like having a display is really useful for that. So I guess maybe the, like

if we're talking at Adafruit products, the reverse feather, the reverse TFT ESP 32 S3

feather, I think there's also a really good Lilygo board that has an ESP 32 S3 in it.

I think there's so many choices, ESP 32 S3. And if you display pick one, if not a QDPI,

those are all good picks. Tod, thanks so much for being on the show. Thanks Paul. Thank

you for listening for show notes, visit www.circuitpythonshow.com and transcripts are available in your favorite

podcast app. Until next time, stay positive.

♪♪

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