443: Vexing Machines
Transcript from 443: Vexing Machines with Chris White and Elecia White.
EW (00:07):
Hello and welcome to Embedded. This week it is just going to be Christopher and myself chatting with each other.
CW (00:15):
Hello.
EW (00:16):
Hello.
CW (00:16):
Hello.
EW (00:18):
You started by asking me if I was enjoying the every other week cadence.
CW (00:25):
Yes.
EW (00:26):
I have to admit I am. Although the fact that we are talking to each other means that I managed to spend two weeks without inviting anybody. I did start some invitations today, so we will get some more guests.
CW (00:38):
Okay. Well, that will be in two weeks <laugh>.
EW (00:45):
In the meantime, you have been doing a lot of astronomy because I hear there was some sort of celestial event.
CW (00:52):
We are just going to dive right into topics? Just get to go.
EW (00:55):
Oh, I am sorry. How are you?
CW (00:56):
I am fine, I am good.
EW (00:58):
How is astronomy?
CW (01:02):
<laugh> Astronomy is interesting. Do you want me to tell the whole story of astronomy from the beginning?
EW (01:07):
Does that not take like 12 billion years?
CW (01:10):
It is very quick. You start with gravity, and then there is the big- But no. Yes, I have been doing a little astronomy. That is a hobby I have had for a long time, but I have put by the wayside for a while. I did a lot around 2000 to 2004, something like that. When I say astronomy, it is not so much observing stuff. It is taking pictures and doing astrophotography.
(01:34):
As you imagine back then, computers and cameras were a little bit different. So I think the camera I had back then was pretty advanced. It was a cooled CCD camera, which is what you are supposed to use for astronomy, if you are being super cool about it. It had a parallel port interface and stuff. Anyway. So there is a comet, and-
EW (02:01):
What is the comet's name?
CW (02:02):
The comet's name is C/2022 (ZTF) E3. I finally got that right after getting it wrong on social media a bunch.
EW (02:13):
Why are we not giving them good names anymore?
CW (02:18):
I think it is because it is too hard to not have a standard. I think that sometimes they have good names, and the boring names. But the boring name tells you when it was discovered, and who discovered it. So the 2022 is when it was discovered. And ZTF is, I think, Zwicky Transient Facility, which is a telescope facility. I found it.
(02:43):
So anyway, this is a comet that recently became visible. And was somewhat, I would not say spectacular, but a good visible target that for a while was good in binoculars and small telescopes. And now is pretty much invisible, unless you got a big telescope or a camera.
EW (03:02):
But you took your SLR out.
CW (03:05):
Yeah. So I have been fighting with thinking I was going to start astronomy again and looking-
EW (03:10):
And you have a giant telescope.
CW (03:12):
Yeah, I have a giant telescope. Well, I have an eight inch telescope.
EW (03:18):
Physically giant. Sorry, I do not really know the telescopeness of it.
CW (03:22):
It is a good telescope. It is reasonably sized. There are many bigger ones for amateur astronomy, but it is a good middle sized telescope. But it is pretty heavy, and the mount for it, while it is a good mount, it is extremely heavy. And so I think all told when I have counterweights and stuff, if I am going to move it outside and use it, it is 75 pounds of stuff that I got to move. And by the time I have got it in place, I just-
EW (03:46):
And aligned.
CW (03:46):
And aligned, I just want to go to bed and not touch anything. So the comet was out there, and I was like, "Well, I have got this other stuff." I have a little camera tracker, which is where you can attach a normal camera to, and all it does is rotate at the speed of the earth's rotation. It keeps stars mostly in place, but if you do not align it perfectly or there are errors and the gears and stuff, it will bounce around. So it is good for wide-field stuff, where you are not going to notice that kind of stuff. And the comet is a wide-field target.
(04:14):
So I just say, "Ah, I will just go out there and see what happens. I will take my camera, put it on there." And I actually got some decent shots the first night, and I was really surprised <laugh>. So I went out a couple more times and got a little better at it. And got some good photos that I have posted in various places, Mastodon mostly.
EW (04:33):
And Instagram.
CW (04:33):
Instagram.
EW (04:33):
I will put at least one in the show notes.
CW (04:36):
So it has got me more interested, because it was easy. The mount and the tripod weighs maybe eight pounds maximum. And the camera is a normal DSLR that weighs a pound. So I can move stuff around, and aligning it was easy. It was just easy <laugh>.
EW (04:55):
The activation energy to get going on this.
CW (04:57):
The friction, yeah. That is the trouble I have with hobbies, is there is too much friction, I do not want to do them. So yeah, I can go into the process a bit more if you want.
EW (05:07):
I do actually. Because that has changed a lot in the last few decades.
CW (05:10):
Sort of.
EW (05:11):
I mean, it is all signal processing and averaging and trying to find good noise. Has it gone in the direction of AI?
CW (05:19):
Mm, a little bit. I can talk about that, but most of the processes are the same. It is just we have bigger computers.
EW (05:28):
And bigger images.
CW (05:29):
Well, yes. So some of the advantage of the bigger computers has been taken away by the bigger images. So my old CCD camera, I used to use, I think it was-
EW (05:36):
Super fancy CCD camera.
CW (05:39):
I paid 1500 bucks for it. It was used.
EW (05:41):
Yeah, I remember it was quite-
CW (05:43):
It was one of the biggest purchases I ever made in my life.
EW (05:46):
At that point.
CW (05:46):
And it was 750 by 400 pixels.
EW (05:49):
Wow. Just so many pixels.
CW (05:51):
My new camera is 6,000 by, I do not know, 4,000? It is 32 megapixels. It is a lot. So you can do the math on that, but the amount of processing that goes into those is a lot more. The way this works, basically- I will go through the pipeline a little bit.
(06:13):
In the old days with film cameras, you used to get high sensitivity film and you would take a really long exposure, as long as you could with your camera being stable on a mount, and develop that. And that was the picture. There were different ways of developing it than with normal photos, but it was pretty much the same process.
EW (06:33):
And there were different ways of light gathering, which is part of the telescope.
CW (06:37):
Yeah. With digital cameras, you can play a lot more games. You still want long-
EW (06:47):
Checkers?
CW (06:47):
Yes. You-
EW (06:48):
Chess?
CW (06:48):
Snake.
EW (06:51):
Okay.
CW (06:52):
<laugh> You still want really long exposures for a lot of objects, not for the moon or planets necessarily. But for deep sky objects, or comets and things, you want really long exposures. Because there are not that many photons coming from these things. They are pretty faint. While you can see them in telescopes, they are often very faint smudgy things, that you see out of the corner of your eye if you are lucky.
(07:13):
So you still want really long exposures, but you no longer have to take one long, big exposure. In fact, you generally do not want to, because if you go long enough, you start to saturate the sensor with bright stars and things. So what you do is you take an array of shorter exposures.
EW (07:31):
A series of shorter exposures.
CW (07:32):
Yeah. These can be anywhere from a second, to a couple minutes, to five minutes, depending on what you are doing, or how stable your mount is and stuff. Once you have got that array of photos, and it can be like hundreds, you throw it into an astrophoto processing program that takes all those and aligns them, because they will not be exactly aligned anymore because things move.
(07:54):
Once it has aligned them, it averages them all together. That is the magic bit, because there are all sorts of sources of noise with taking pictures of anything, or any sort of optical photometry kind of thing. Right? So there is noise from the sky, there is background sky glow, and light pollution. There is noise from the sensor itself from getting hot, so there is thermal noise that shows up. And there is noise when you read out the sensor for the whole digital signal processing, analog signal processing chain.
(08:37):
A lot of those are uncorrelated. There is random. So if you average a whole bunch of images together, that all goes away. And so your signal to noise ratio goes way up. And for stuff like light pollution, I may get this wrong, but even your faint objects, the photons are all coming from them in a consistent way, and the light pollution is maybe less consistent. When you average them together, you can start to drive the base level noise down, when you stretch the image out in contrast.
EW (09:12):
Oh, I did not get that. Because the stacking of the images, it made sense to me in a dithering sort of way, where you take multiple too fast samples on an ADC, and then you average them together to get another extra half bit.
CW (09:34):
That is another thing you can do, called "Drizzle." Maybe I am explaining that wrong. So it is more about the long exposure, because-
EW (09:43):
With sky glow it is harder.
CW (09:43):
It is more about the long exposure without saturating. So if you take a really long exposure, the sky glow might saturate. If you take a lot of short exposures, the sky glow will not. So the longer you go, the sky glows the same in every image.
EW (09:57):
The more sequence images you have. "The longer you go" is ambiguous.
CW (10:05):
Yes. The more sequence- Right. Sorry. The total exposure of all of your stack, the better it gets. Because you get more photons from your object, which is going to be higher than the background sky glow no matter what. Even if it is one or two photons per whatever. So that is always going to start to dominate. Then you can in post-processing contrast stretch out the background radiation as long as it is not saturating the sensor. I am more fuzzy on some of that. So that is what you do.
(10:39):
When the images come out of a camera from photography, you usually do not see anything. If you just opened a picture from Photoshop, you might have one or two bright stars. That is because when you are in a linear transfer function between the sensor data and your screen, the astrophoto images are in a very narrow band of values for your sensor. So that needs to be stretched out so you can actually see it. So there is usually like an exponential or an S curve or something you apply to take the very narrow dynamic range that you have actually captured, and stretch it out so you can see it. It is kind of weird.
EW (11:26):
Relating back to ADCs, it makes a ton of sense.
CW (11:30):
Yeah. There is a ton of software packages that do this stuff. I use one called PixInsight, which is kind of the gold standard right now. It is sort of expensive, but there are a lot of free ones out there that do a lot of the similar stuff. Siril is a new one people like, S I R I L. There is DeepSkyStacker, and a few others.
(11:48):
It is fun! It is kind of like fishing in a way. You are just out there doing nothing <laugh>, and then eventually you might have caught a picture that is of something that everybody else has taken a picture of, but it is your picture.
(12:01):
And it is fun to look at the star charts, and see what you accidentally picked up. I was doing that with the comet photos a little bit, "Oh, there is a little smudgy nebula there in one spot." Or there are some dark clouds of interstellar dust and things that block stars. That is always interesting to see, if you expose long enough.
EW (12:25):
Yeah, I was surprised to see those in your images. It looked like you had-
CW (12:28):
Clouds.
EW (12:29):
Black clouds. And I was like, "That does not really make sense. The sky should be full of stars." But it is not actually.
CW (12:36):
It is full of stars. Stars and dust.
EW (12:38):
Yeah.
CW (12:40):
So yeah, I have been enjoying it. It is hard, and there is stuff I do not understand. You set things to advanced, so the software has some things I do not understand I need to study up on.
EW (12:52):
But now the post-processing is hard, instead of the activation energy.
CW (12:58):
Oh, because I can take out the little camera?
EW (13:00):
Yeah. You can choose to spend more time on it later.
CW (13:04):
Yeah. It is much more comfortable to sit on a couch with a laptop, than stand in the freezing cold.
EW (13:10):
Even with the bigger telescope, it was an effort to do that. It is like, where is the effort? Is it at the starting point, or at the ending point? I have been thinking a lot about effort, and how to do things without making yourself do them.
CW (13:29):
Yeah, no, I am thinking about that too. The effort thing is right, because for this, it is like the sky moves, and night is only happening sometimes, and clouds happen sometimes. A kind of a urgency.
(13:41):
Got to get it set up, got to get it exposing while there is a window, while the object I want to see is not blocked by the house or the trees or not pointing- There is a lot of that stuff. It is like, "Got to get it. Got to get it." And then when you are post-processing, it is like, "Well, I can spend three days on this." Oh, you asked about AI.
EW (14:00):
Yeah. Is there- Technically you could say, "I already know what everything is going to look like, so I will just sharp it up, so it looks like the canonical image."
CW (14:11):
Er. Yeah.
EW (14:11):
Which seems not good.
CW (14:14):
You can always do that with everything right now. But there are some AI programs...
EW (14:17):
Well, except that there are still 1.5 billion people on Mars.
CW (14:22):
I do not talk about that. <laugh> It is 2.5.
EW (14:25):
<laugh>
CW (14:25):
For all image processing, there is a bunch of AI stuff now that does noise removal or sharpening or just general enhancement stuff. Those are becoming more popular and they work pretty well. For astronomy in particular, I have used a generic photo denoiser on them. That works fine.
(14:48):
There have been some specific AI ones for astronomy. I used one of them on the comet image when I was trying to play around. When you are doing comet images, there is a bunch of games you play, where you want to enhance the comet a lot, separately from the stars background and then recombine them. I did not get it to work. I was trying to bring out more detail in the comet doing that.
(15:09):
One way you do that is you remove the stars from the comet. There is a bunch of ways that you can accomplish that. One is to do what is called "plate solving," where the computer figures out exactly where you are looking. And since it has a star map, it just subtracts all your stars <laugh>. It says, "Oh, you are in this right ascension and declination. Here are all the stars I see. I know what they are. They are gone." But there is also another program-
EW (15:33):
It is kind of magic.
CW (15:35):
Yeah. Another program I used, I actually tried a trial of it which is AI, called "StarXTerminator." And it is a-
EW (15:40):
<laugh>
CW (15:40):
It is a neural network. Star Eliminator? Star Exterminator?
EW (15:44):
<laugh> I hope it is Star Exterminator. That is so awesome.
CW (15:46):
I think it is Star Exterminator. Anyway, you throw your stuff at that, and it removes all the stars using a neural network and just leaves the comet. Then you can do your processing that way. So there is a bunch of stuff like that. And then there are specific astronomy, denoisers and sharpeners.
(15:59):
I do not think people realize how much processing goes into all astronomy images. You cannot take a picture of the sky and then get it out of your camera and show it to somebody. Even if you contrast stretch it as your only thing, it will look nice sometimes, but-
EW (16:21):
You can do that for the moon, but that is about it.
CW (16:23):
Yeah. You can take a long exposure and just contrast stretch it. That is what film used to do. Right. But it is a lot harder to do that and get a satisfying result, especially if you need to expose 30 total minutes or something. Even stuff like Hubble and the James Webb telescope, there are tons of post-processing that goes into those kinds of images. It is a lot of work.
(16:49):
There is always a little bit of an artificialness to the image you are producing. But I think my goal, and other people's goals, is just not add data that does not exist. If there are values coming from the sensor that you want to enhance or bring up and others that you want to move down, I think that is totally fine. Because you are trying to see details that are hard to see.
EW (17:11):
How much of the processing pipeline do you not understand?
CW (17:17):
Of the one I used?
EW (17:19):
Yeah.
CW (17:23):
I am trying to think the pipeline I used. Obviously get the camera images, and there is a format conversion, so I kind of know that. There is the registration process where it aligns them. I think I understood that at one time. I am not sure I do anymore, because I think it is a lot smarter. Back in the old days, you used to take like a master image, and then you would mark several stars by hand that you wanted-
EW (17:47):
Fiducial stars.
CW (17:47):
Yeah. That you wanted it to align to. Then it would do a bunch of stuff, and try to pick the high quality images based on some focus factors and things. I kind of understood that. And then I probably used cross-correlation and other things to do that.
(18:03):
Now you just throw a pile of images at this and say, "Please go. Thank you." I do not know how that works exactly. That is a lot smarter, and nicer, because you do not have to go mark stars or throw out images. It just does all that stuff. You can parameterize it all and change stuff to like, "Oh, here is what I want you to use for quality factor and stuff." But for the most part, the defaults just work, unless you have got a funny image. I kind of understand that, but not really.
(18:29):
Then there are some other things now that- There is dynamic- There is all this stuff. When you take an image of the sky, there is often a gradient, either because of your lens is vignetted, where that means the corners of your lens might be a little darker than the center.
EW (18:49):
Mm-hmm <affirmative>.
CW (18:49):
That happens with all lenses. Most people do not care when they are taking daylight images or brightly lit images. When you are taking faint images that tends to show up. There are also gradients in the sky from light pollution or just all kinds of things. You want to remove the gradient, otherwise you have got a bright glow in the middle of your image and then dark corners. There is stuff that analyzes that and just divides it out. I guess I could come up with how that works.
(19:16):
There are other things like automated color adjustments and things. I guess they are mostly arithmetic, but I do not really know how they work. If you are looking to get into this hobby, you can get into it for a lot of money or a ton of money. Nah, it is actually with a DSLR and a star tracker, you can do an awful lot. Which is kind of exciting.
EW (19:44):
It is, because a lot of people have the DSLRs.
CW (19:46):
Yeah. The star tracker is like-
EW (19:46):
It does not have to be your bigger one. It could be the older version.
CW (19:53):
Yeah. Any modern, where modern is since 2010, 2008, camera has got a decent enough sensor for this stuff. And like I said, a lot of it comes down to just taking a lot more images and averaging them. So if you have got a less good sensor, okay, take more images.
EW (20:14):
You were doing this in our front yard, and people do drive by on the street.
CW (20:19):
Yeah.
EW (20:20):
Did the program just drop those?
CW (20:23):
No, I did not see that affected much. So I am not sure. I would have to look through the images and see. Probably I should have rejected more images than I did, but I was not really thinking about it.
EW (20:38):
The images you got had way more stars than I could see. Although realistically, I do not know that there are seven Pleiades, so how many I can see is not really the question. Because you were stacking and getting the fainter stars. How dark does the sky need to be for someone to do this?
CW (21:06):
Not dark at all.
EW (21:08):
Because the software can take care of some of the sky glow.
CW (21:12):
Exposure time kind of heals all sins of the sky. The photons are still getting to you from everything, from the faintest objects. They are still getting to you. They are not blocked, it is just that there are other photons competing with them. And so the more-
EW (21:28):
As long as you do not saturate, you can get both.
CW (21:30):
Yeah. I have seen some of the most spectacular, ridiculous, Hubble-like deep sky images from people, amateur astronomers who are in Chicago.
EW (21:47):
To get the spinny thing, the "making sure the stars do not go in a circle" thing.
CW (21:54):
<laugh> The star tracker?
EW (21:55):
The star tracker. You do need to be able to find Polaris.
CW (21:58):
At least to be able to find Polaris. But it is a pretty bright star. The way you align usually is through a small telescope that is embedded in the star tracker or the mount. That will help you even if it is too faint, and you get it in the ballpark, you will be able to see it in that. If you cannot see Polaris, then yes, you probably should not be doing any astronomy.
EW (22:17):
But, I mean-
CW (22:18):
But it might also be day.
EW (22:20):
<laugh> Right. It might be daytime.
CW (22:22):
In which case you can look at the sun, with a- No, with a filter, a proper- Never mind. Do not look at the sun!
EW (22:27):
Do not look at the sun.
CW (22:31):
There is a scale called the "Bortle scale" of light pollution. It goes from one to, I think-
EW (22:36):
Yeah, I remember you were telling me about the Wordle scale.
CW (22:38):
<sigh> Yes. The Wordle scale.
EW (22:40):
I was doing the Wordle, and he was telling me about the Bortle scale and I did not understand.
CW (22:47):
<laugh> The Bortle scale goes from one to nine, I think, or maybe one to eight. It is just a measure of how light polluted your sky is. There is a rubric to evaluate, so Bortle one is the least light polluted sky, and that is where you would be in the middle of the Atlantic or something.
EW (23:03):
And you said you can see shadows from star lights.
CW (23:07):
The center of the galaxy casts a shadow. That is how dark it is.
EW (23:11):
I have never been someplace that dark
CW (23:12):
And Jupiter and Venus are bright enough to ruin your dark adaptation night vision. So that is how dark that is. It is very few people have encountered that. But then it goes down. Two is probably mountains, remote desert. Three, similar kind of thing. Three is like rural. And then four is a suburban/rural transition. We are kind of in four.
EW (23:37):
I believe that.
CW (23:37):
Based all the maps.
EW (23:38):
If people did not drive by our house.
CW (23:40):
I think we are in four if we just go a mile one direction away from the neighborhood.
EW (23:46):
Yeah.
CW (23:49):
Most suburban people are probably somewhere between five and six. I think in San Jose, we were in six or seven.
EW (23:56):
But you got some good shots there.
CW (23:57):
And I got some good shots in San Jose, because it just works. It is really scary. Yeah, when you sit there with that camera, I could get stuff out. Take a longer exposure and immediately see something. It was just weird to point at an area of the sky where I could not see anything in the telescope. I could see some brighter reference stars to know where I was on my star chart, and the object would be invisible, and just sit there and take exposures and have this invisible object appear. It was very cool.
(24:27):
But there are all sorts of new stuff. Like they have- This whole principle of of averaging stuff, people have built it into all-in-one kind of telescopes for observings. You can go out with this telescope and point it, and just look on your iPad or iPhone. It will accumulate while you watch so you can see things and observe that way. They are coming out with neat new products that are more for just fun using, using this kind of imaging stuff, than for serious astrophotography.
EW (24:58):
So I recently built a pinhole camera. Can I use that for astrophotography?
CW (25:07):
Maybe? You know what you could use it for? If you ever see where somebody exposes for an entire year, the sky. They get this figure eight of the sun, all the sun's positions. I do not know if that would work with a pinhole. I do not know if that is multiple exposures or not. I do not know what would happen. You would have to expose for a long time, which means that you might get star trails. It would be interesting, I think. Yeah, it depends on the film too. Like if the film is not very fast, it might be so faint that you do not get much.
EW (25:50):
So in paper engineering class, I made a camera, a pinhole camera. The instructor sent us some special paper that is very light blocking. And of course, she helped us through the instructions of making the camera. She also sent some film, and instructions for making a developer at home, using caffeine and baking soda.
CW (26:18):
Do not believe that for a second.
EW (26:21):
But I have not tried the pinhole camera yet. For me, it was more about the paper. One of the special things about the pinhole camera is the focus is general. There is no...
CW (26:38):
It has a very wide depth of field.
EW (26:40):
Wide depth of field. That is how you say it.
CW (26:41):
Yeah.
EW (26:43):
So I should do something that uses that. But since he has been doing astrophotography, I keep wanting to take the pinhole out there and leave it on the roof for a couple hours.
CW (26:53):
We could try it. It might blow away. That is the thing, you got to make sure it does not move.
EW (26:59):
I got to make sure it does not get wet.
CW (27:01):
<laugh> That too.
EW (27:01):
It is made of paper. Yeah, so I am not going to become a pinhole photographer, or one of those people who takes pictures using the pinhole by opening their mouth. I do not know. I do not think that was a good idea. But there were two different artists!
CW (27:26):
I know. I think they put the camera in their mouth.
EW (27:30):
They used their lips as the pinhole.
CW (27:35):
Oh, maybe that one did. But I saw another one where somebody put a pinhole camera in their- Because they could see the back of their teeth. So it could not have been the...
EW (27:44):
Oh yeah, no. This was- You could not see the back of their teeth. You could just see who they were. I do not know.
CW (27:50):
Anyway, so how is paper engineering?
EW (27:53):
It is good. I really, really like not being in charge.
CW (27:57):
Of the class?
EW (28:00):
Of class. Yes. I like that it is a cohort. The other students are really interesting and have different perspectives. I know with my class, people have said that they were sad when the class ended, because suddenly their Saturdays did not have that to look forward to. I think that is going to be true of this. I kind of wish I could just continue the class, even if the instructor did not do it. I feel like I have so much more to learn from the other people.
(28:33):
I was amused that one of the people in the class who is a children's book author, pretty successful, started to have a cohort based class herself. In part because she took this one and enjoyed it and did not want to go anywhere to teach the class. So she is having her own children's book writing class, which filled up in a very short amount of time.
(29:05):
So I am really enjoying that part. The paper engineering is interesting. We are getting into popups, which is not something that is super cool to me. I think the books that have them are super cool, but it is not something I like to build. It is interesting what things you can learn from a book, versus the things that you need more people around.
CW (29:36):
Yeah.
EW (29:39):
I actually picked up a pop-up book today, because I was interested. But I could do all of the exercises in the book, and I could probably actually do more pop-ups than I can do after week nine in a ten week class. But I would not have learned more about Bruno Munari, and pinhole cameras, and Canadian children's authors, and Italian bookmaker- There is so much more, even though I would generally rather read a book.
(30:14):
One of the things from there, that I wanted to mention, is the idea of rigid flat foldable structures. This is one of the areas that is a crossover between origami and space. Whenever they talk about, "You should see this giant, cool, space telescope, it is made of origami," what they are talking about are the patterns that can be folded so that they end up totally flat. Kind of aggregating the material in a different form, and then being able to spread it out into a flat structure like solar panels.
(30:56):
One of the things we did in my paper engineering class, was to go over these as tessellations. I have done a lot of tessellations. I was not excited about that. But once we started to talk about the rigid flat foldable, I ended up down the rat hole, and got very into the different types of that. Miura-ori folds are probably the most well known, but Yoshimura folds is one that I have fallen in love with. They tend to make arches. Okay, I am going to do origami on the podcast.
CW (31:37):
<laugh>
EW (31:37):
I did not bring down a piece of paper. I was tempted, but-
CW (31:41):
It is all right. I just got done talking about photography on the podcast.
EW (31:46):
You take a piece of paper, a square, and you fold a diagonal, then you fold the two corners into the center. Then you make a diagonal in the other way, fold the two corners into the center, and now you fold one direction- Those are all mountain folds say, so they are all pointing one direction. Turn it over, fold mountain folds in the other direction, so that you have eight lines, which is in half and half and half.
CW (32:18):
Okay.
EW (32:21):
Now if you just make all of those folds-
CW (32:23):
Like a pizza.
EW (32:25):
Not like a pizza.
CW (32:26):
Then in half and half and half. Eight lines.
EW (32:30):
No, sorry. Eight horizontal lines.
CW (32:33):
Oh, see, I was thinking radial.
EW (32:35):
No, horizontal lines. So now you have two sets of diagonal lines, and one set of horizontal lines. That is eight horizontal lines, and four diagonals in each direction. So four, four and eight. 12 lines.
(32:50):
Now you just fold these, so the diagonals go one way, and the horizontal goes the other direction. It will fold flat. At first it will not. It will make this little arch, and then it will fold flat into an arch shape. And so if you wanted to, I do not know, make this out of large metal and store a bunch of shelters, you can store them as a small...
CW (33:23):
Pack
EW (33:23):
Pack, and then setting them up is pretty easy. Yoshimura folds. I like them. So I made a little program that would let me try different angles. The one I described would be a 45 45 angles, but you can do them at different angles and get different arches and different shapes, blah, blah, blah.
(33:45):
But then I really like to do curved origami. So I added sine waves, which led to some pretty weird and cool things. To be fair, I saw somebody else had done this, and I wanted to try it. And I had saw someone else else, Ekaterina Lukasheva, did something that I thought might be a result of Yoshimura folds and sine waves. So I did a bunch of those, and they have turned out really good. Weird patterns, but still very comfortable patternish sorts of things.
CW (34:25):
Mm-hmm <affirmative>.
EW (34:27):
Then I added a little bit of randomness with how long each one was and where it started. And that was pretty cool, but weird. And then I started adding random start points for the sine. That is where things went really strange, because it is almost disconcerting to look at. There is a pattern there because there are sine waves.
CW (34:56):
Ah.
EW (34:57):
But pattern has been randomized in a way that I find-
CW (35:04):
What you should do, is you should take a signal for something and you should Fourier transform it, and pick the big peaks and use those as the sine wave frequencies. So you could have an origami, that has a secret message...
EW (35:20):
<laugh>
CW (35:20):
But it is broken down into...
EW (35:25):
Okay. Well, I will put that on my list.
CW (35:27):
<laugh>
EW (35:29):
So as I am doing this, I am making more and more Python code to do it.
CW (35:36):
Right.
EW (35:38):
And I do it on a Colab, because I do not mind sharing these things, and that is the easiest way for me to do it. Then I output SVGs, and they go to my Cricut. But I have heard recently that SVGs using points are bad for printers like that, and I need to switch to Beziers.
CW (36:02):
It depends on if the printer supports the interpolation, I think. Like I remember not all 3D printers could do that, I thought, but maybe I am wrong.
EW (36:12):
But I think the Beziers are good for everybody, and the points are kind of bad for most things. So I have that to do. I have more randomness, I have more folding. I have been pretty happy with the origami lately. It is weird that I now probably should be more entertained by the pop-ups. But I am still back in week two of the paper engineering class of playing with these tessellations, although rounded instead of straight.
(36:41):
Then there is a book that I want from Robert Lang. He was on the show.
CW (36:45):
Mm-hmm <affirmative>.
EW (36:47):
Twists, Tilings and Tessellations. I mean, I have, I want to read.
CW (36:52):
Ah, yeah, I thought you-
EW (36:54):
It is full of mathematical proofs.
CW (36:55):
Oh no!
EW (36:58):
They do not really get to this sort of tiling tessellation thing until chapter two. And chapter one was boring, and math heavy. I just need to get to a mental place where I can do that.
(37:15):
And that is astronomy and origami for those of you who- Sorry. Okay, let us see, what else? Next on my list is burnout sucks. Yes, burnout sucks. How are you doing with that?
CW (37:33):
I do not know. I am too busy to be burned out. I think I am still burned out, but I have added so many activities that I am ignoring it. Like I am taking another music class. The previous music class was great, but it was really intense. This music class is less intense, but also takes some time and effort.
EW (37:53):
And it is a totally different area for you.
CW (37:55):
Yeah. And I did the astronomy stuff, and I am doing some more session work for music.
EW (38:06):
People ask you to do drums or bass.
CW (38:08):
Yeah. So that is coming along. I have had some very manic days in the last couple of weeks, where I have been like, "Oh my God, I have done like eight things. What am I? Exhausted." Which have been great. I enjoy that, but I am still not really feeling like I want to work. So I do not know. I mean, we have talked about burnout a lot, and I do not think I am at the place where I just want to sit around. I have a lot of stuff I am excited do. It is just none of it is work.
(38:37):
So I do not know what that is. That may not be burnout. That may just be I need to retire. Because truthfully, I sit down and spend three hours poking in PixInsight, and be perfectly happy to sit at my computer doing that. But if somebody paid me to do it, I probably would not want to do it <laugh>.
EW (39:00):
<laugh>
CW (39:00):
So I do not know what that is. That is weird.
EW (39:05):
It is usually me who cannot read a book, as soon as somebody says, "You should read this."
CW (39:08):
Yeah. I do not want to process anything sold, bought, or buy anything process- Yeah, anyway. The work I am doing is kind of interesting. So I am having a little more fun with that. But that is wrapping up soon, so we will see.
(39:24):
I am enjoying the music stuff. I wish I could figure out a way to make that a thing, but I think it is just going to have to be a non-compensated vocation for a long time. But you are still in burnout zone.
EW (39:41):
I am.
CW (39:43):
But you do all this paper engineering stuff, and you sit and focus on your class. So you can do things.
EW (39:49):
I do, but I am really tired afterwards.
CW (39:50):
Yeah.
EW (39:50):
And I can only do it for a little while. I do have fun with it. And what I am working on for work is interesting, and almost done and probably pretty good, but...
CW (40:04):
Well that work was not- That was...
EW (40:09):
I totally misestimated it. Anytime you are looking at something and you say, "The hardest part of this is going to be how to test it," you should not estimate it-
CW (40:18):
<laugh>
EW (40:18):
Without thinking, "Oh my God, I am going to have to write a full simulator." Because if the hardest part about it is testing it, that means that is the part you are going to have to do. That is the actual work.
CW (40:32):
Yeah. Well, I have watched you do some of it, and I have tried to help you with a couple of things that I probably did not have answers for, but it did not seem exciting. It seemed like just a little couple steps above scut work. I do not know if that factors into it, but I think if you were working on an image scanner that was going to fly on the Hubble Space Telescope, you might be a little more into it.
EW (41:02):
Maybe. But I only get a couple of really good brain hours a day, and then I have to do something else because my brain just says, "No."
CW (41:18):
Oh, okay. See, I am still very tired a lot of time like that, but if I switch to something else, I can continue.
EW (41:27):
No, I am still in the stage of at some point on almost every day, even on the weekend, it just is like, "No, no, there will be no more output." We were talking about this in the paper engineering class, about needing some forms of input before you can have output. One person said, "It is like juice. I am a juice machine. I can output juice, but at some point, if I do not have oranges, you do not have juice." My brain is a juice machine seemed very yes, like that.
CW (42:09):
<sigh>
EW (42:09):
So you are winding down your project. I am winding down my project. Are we asking people to give us more projects?
CW (42:19):
No.
EW (42:21):
No.
CW (42:22):
Not right now.
EW (42:23):
Not quite yet.
CW (42:24):
I would very much like to have a few months off, which would be the first actual few months off, I can remember since...
EW (42:36):
Grad school?
CW (42:38):
Yeah, probably. I fully intend to take some of the summer.
EW (42:43):
It is February.
CW (42:45):
Some of the summer and its penumbra.
EW (42:49):
Huh. Well, I too am planning on taking a little bit of time off. But probably not that much. We will see.
CW (42:58):
I do not know. Maybe I will just take spring off. Whatever.
EW (43:02):
We will figure it out.
CW (43:05):
Whatever season, it does not matter.
EW (43:06):
Once we start needing to mine salt again, we will start mining salt.
CW (43:09):
Yeah. Anyway. Yeah. It is not like I want to do something for myself. Like I do not have any ideas for a product, and I do not want to do that stuff. I do not want to do the- It is kind of like marketing music. I do not want to do that. I certainly do not want to figure out how to sell something and manufacture it, even if it is software. I do not know. I need a break. But not a break where I do not do anything, just a break where I do not do what people tell me to do.
EW (43:45):
One of the things you have been doing for work is some actual CAD in 3D printing, which-
CW (43:50):
Oh God!
(43:50):
So many people are going to be like, "Oh yeah, I do that all the time." But then there are other people like me who are like, "Yeah, I do not know how to do that. And I heard it is hard."
(43:58):
I complained on previous episodes, recent previous episodes about all of this.
EW (44:01):
True.
CW (44:04):
Yeah, no. I am doing some drone stuff and I have a big drone over here. You can look at it. It looks like an Imperial probe droid.
EW (44:13):
Oh my God, that is enormous.
CW (44:13):
You have not seen it? Did you not see it?
EW (44:15):
I do not think I saw it outside the garage, and it looked smaller in the garage.
CW (44:18):
Well, that is with all of its blades folded down too. Those arms come out, so those two foot long arms. So when it is fully extended, it is quite a terrifying thing.
EW (44:29):
If you told me that was named Star Exterminator, I totally would believe you.
CW (44:33):
<laugh>. It does look very Imperial.
EW (44:34):
Yes.
CW (44:36):
It has an 11 pound payload capacity. So it could carry an infant, if you wanted to have an infant delivery service.
EW (44:45):
Stork?
CW (44:45):
Keep it away from the blades.
EW (44:49):
<laugh>
CW (44:49):
So what I am doing with that, is for a client. Without going into great details, we are doing some stuff with neural networks, and I needed to mount an NVIDIA Xavier to it that runs our code.
(45:00):
I delayed doing this for months, trying to figure out how to do this, because I knew it was going to come down to me CAD designing something, and I am terrible at it. I tried to CAD some stuff for other parts of this project, and failed miserably, getting to the 95% point. But the 5% point where the screws align, or where the board fits perfectly, was not working. And I gave up. But this one I had to figure it out.
(45:28):
So yeah, I came up with a mounting mechanism that will securely mount this. It was not that bad, because it was a simple structure. It was basically a plate with some curved places for rods to sit, and then screw holes. So that was within my capabilities, turns out.
EW (45:48):
And it looks good. It looks solid.
CW (45:50):
But that is a pure extrusion. It was easy because I made the profile, and then just extruded it. And drilling holes is pretty easy in CAD programs. Since that was the extent of it, it was within my capabilities. But boxes and things with lids and stuff like that, and places to mount boards, that gets tricky. That is still beyond me. Yeah, I was pretty happy with that. But this drone is, oh my god, it is a really expensive professional drone. And it is complicated!
EW (46:22):
Really? What a shock!
CW (46:24):
It has got this flight controller computer. It has got an Android tablet that it comes with. That is that thing there, that runs this weird software. It has got this flight manager, and mission planner stuff, and all this calibration and set up.
(46:39):
We got a gimbal for it that we are going to mount the camera to. That took me like three hours to assemble this morning. Because it was fiddly with little Allen keys, and the entirety of the documentation was mostly that sheet of paper right there on the floor.
EW (46:54):
<laugh>
CW (46:56):
It also comes with 50 cables. And I do not know which cables to use to, because some of it has to plug into the flight controller, some of it has to plug into power, some of it plugs into itself. And some of the cables, turns out it just gives you all the cables you might need, depending on what kind of drone you are hooking it to. And then there was one that was for Bluetooth, but I do not see any blue- Anyway. Complicated.
(47:17):
Then once you get that, you have to configure it in the Android thing, and get it all to work. This is not stuff I am enjoying that much. It is a lot of fiddly, "some assembly required" stuff. And then this thing has got to fly and work and not crash. Oh, and then I got to get the power to work. I did not even talk about the power. I got to power of the Xavier, right? The Xavier is this little NVIDIA computer and it-
EW (47:40):
Did you not decide you are powering it separate from there?
CW (47:42):
Ah, maybe, but it has got <laugh> a barrel jacket that takes 19 volts at like five amps or something. Maybe four amps nominal. So they got it powered from the drone, because the drone is in the sky. I am not going to have a wall wart flying in the sky with an extension cord. So I found some DC-to-DC converters on Amazon that were in the right voltage range. I tested that and hooked them up. There is an AUX port from the batteries on the drones. So that all worked.
(48:08):
But I do not really know if it is going to work in flight, because I do not know if the voltage is going to wiggle around a lot while the throttle is being jammed up. So I do not know, I got to figure out how to make that stable or test it on the ground, because I cannot really test this thing. You have seen it. I cannot take this in my backyard and fly it without chopping down half a forest. There is nowhere around here I can take it. I think you have to be FAA certified anyway to fly something like this. This is not a 250 gram <laugh> drone.
(48:42):
I thought about strapping it down and throttling it up just to see what the power thing does. Yeah, that is my main worry is conditioning the power, so the DC-to-DC converter does not trip out.
EW (48:59):
Why do you not just pop some more batteries in there?
CW (49:01):
Because I am not sure I have batteries that are at the right voltage for the DC-to-DC converters I have. Because I do not have the 24 volt batteries that this monstrosity takes. I have normal drone batteries, which are like 9.6. So, instead of a buck, I need a bunch of boost and buck converters.
(49:22):
That is my story. I will be glad to have this out of my room where it stares at me. It has a little beaty GPS antenna. Oh, it is so loud. You turn the thing on and it beeps at like 130 decibels, until you push the big safety button, which you have to hold down, which is between the blades!
EW (49:45):
<laugh> That seems bad.
CW (49:46):
You see? Look, see those two yellow connectors right there? Yeah, those. The safety button is to the left of that. Those two blade arms, you have got to unfold before you do any of this. And so you are sticking your hand between vinyl record sized helicopter blades to push off the safety button. It is a little terrifying.
EW (50:12):
Well, why do you not take the blades off? You would not want to push the safety with the blades on, would you?
CW (50:19):
It is extremely hard to take the blades off. You have to Allen key them off. You would not want to put them back on with the safety off. You cannot get the blades off. So yeah, it is a very vexing machine. I am vexed by it. Once you turn the safety off, it beeps in different ways.
(50:37):
Oh, and then the Android computer starts yelling at you in this autopilot "You are about to crash" kind of voice, and says things like "GPS not connected. No satellites found."
EW (50:51):
Let us see. Let us talk about something more positive.
CW (50:55):
That was positive.
EW (50:57):
Was it? You made her sound very mean.
CW (51:01):
Well, she was mean.
EW (51:05):
CircuitPython now has a Jupyter Notebooks host?
CW (51:08):
It has for a while. I did not know this. It came across in the Slack. MicroPython does, but it turns out CircuitPython also does. So if you want to use Jupyter Notebooks, and have the Python code in the Notebook run on your CircuitPython target, that works. There is a link we will put in the show notes. You can set up a Jupyter Notebook, and connect it to your CircuitPython compatible board. It runs each cell. It is running on the device, so you can do all your embedded stuff in development there. I thought it was really cool, because normally the pattern with CircuitPython is you have an editor on your computer and you edit the code, and then you save it to the device over USB, and then run it. So the iteration time is pretty fast. But this is like, if you want to develop stuff, it is like running in the REPL basically. But you still got the code that you can copy and paste. So that was really cool.
EW (52:10):
I really like Jupyter Notebooks. I do not think it is that hard to run. One of the things that I did not understand about Jupyter Notebooks to start with, was that it always needs a server.
CW (52:25):
Yeah.
EW (52:25):
You cannot just run Jupyter Notebooks on your computer, unless you have something for it to talk to.
CW (52:32):
Yeah.
EW (52:32):
Like a Python-speaking backend that is a Jupyter Notebook's backend. This is hidden from you when you do Colab, because it looks just like Jupyter Notebook, but you are already attached to your fake machine that somebody else owns.
(52:53):
Jupyter Notebooks is really nice because you can have the code and documentation in pretty documentation form. So it is really easy to say, "And now I am doing this," without getting too bogged down in how pretty your comments are, because they look like text comments. They look like Word comments.
CW (53:11):
Yeah.
EW (53:13):
So yeah.
CW (53:14):
Yeah. No, I should not have been a surprise that this works, but I never considered it.
EW (53:19):
Yeah. It is a nice way to do things.
CW (53:22):
It would be a completely different way of doing embedded development. It should be fun to explore.
EW (53:29):
We got a couple of good links recently from our Patreon Slack group. In fact that is what the newsletter was last week, since we did not have a show to talk about. So if you want to sign up for the newsletter, you can get some of the good Slack links from Patreon folks. Or you could join the Slack group if you give us a buck on Patreon.
CW (53:55):
I think we should raise that for inflation. Should be like $1.20 now probably. I am kidding.
EW (54:02):
I knew that you were kidding. I just was not sure what I was going to say to it. So, cool.
CW (54:14):
<laugh> All right.
EW (54:15):
All right!
CW (54:17):
Yeah, we do not have to talk about that other thing. Yeah. So that is the state of the world.
EW (54:23):
That is the state of the world, in our universe at least.
CW (54:28):
If anybody has a source for really flexible USB 3.0 cables, drop me a line. For the drone the camera we are using is USB 3.0, but it has to be on the gimbal. And all the USB 3.0 cables I have and I have seen are fairly stiff. That is not going to work very well, because it is going to be fighting the gimbal, or the gimbal is going to be fighting the cable. What I want is a really thin or pliable USB 3.0 cable.
EW (55:00):
Why did not the gimbal come with the right cable?
CW (55:02):
Gimbal does not know what camera you have.
EW (55:05):
You said it came with every cable.
CW (55:07):
Yeah, but most <exasperated>.
EW (55:09):
Sorry. <laugh> Oh, your life is so hard.
CW (55:17):
We cannot order stuff. Everything still has huge lead times with this drone stuff. It is crazy.
EW (55:23):
It is funny. The chip market is starting to move, or has been starting to move. Things are not nearly as bad as they were.
CW (55:31):
The gimbal took months to get. The camera has taken many weeks to get. The drone itself took like six months. That was incredible <laugh>.
EW (55:42):
Does the drone have a name?
CW (55:45):
It is the Aurelia X6 Standard.
EW (55:47):
No, I mean, have you named it? Do you need googly eyes for it?
CW (55:51):
I do not need a connection with it.
EW (55:53):
You are not going to bond with the drone?
CW (55:54):
No, I do not want to bond with the drone.
EW (55:56):
I can give it really like evil googly eyes.
CW (55:58):
And luckily I am not going to fly the drone when we do testing. So if it crashes, it is not my fault.
EW (56:04):
It may not be your fault, but you will probably still be present.
CW (56:07):
You think I should wear a helmet when we go?
EW (56:10):
Hard
CW (56:10):
Hard hat?
EW (56:14):
Yeah. And that is the show. Thank you to Christopher for producing and co-hosting.
CW (56:18):
<laugh>
EW (56:18):
Thank you for listening. You can always contact us at show@embedded.fm or hit the contact link on embedded.fm.
CW (56:28):
And if you take all of our shows and average them together, there is enough exposure time that you get a decent show out of the 400.
EW (56:36):
[Winnie the Pooh excerpt]