UmbralRaptor changed the topic of #kspacademia to: https://gist.github.com/pdn4kd/164b9b85435d87afbec0c3a7e69d3e6d | Dogs are cats. Spiders are cat interferometers. | Космизм сегодня! | Document well, for tomorrow you may get mauled by a ネコバス. | <UmbralRaptor> … one of the other grad students just compared me to nomal O_o | <ferram4> I shall beat my problems to death with an engineer.
<kmath>
<cosmos4u> Why @Philae2014 wouldn't talk much in 2015: remaining explanations after the lander was seen by OSIRIS. From a talk… https://t.co/TLPUsM1oZn
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<SnoopJeDi>
Ellied, are you familiar with this scanlime lady that egg|cell|egg posted? Content seems very up your alley
<SnoopJeDi>
Ah, I see that she is following her on Twitter. Shocking :P
<Qboid>
[#34] title: Explicitly define timeout parameter in irqWait | Currently, the `timeout` parameter in irqWait passes improperly to the call to `GPIO.wait_for_edge`, setting the `bouncetime` parameter instead. This causes the example `recv.py` script to fail, as packets sent more frequently than the `bouncetime` setting (30 seconds by default) cause the IRQ pin to go low without being caught by t
<Ellied>
eight characters. Not sure what part of the bell curve that's on for length of first pull request.
<Ellied>
This wasn't planned at all, I just stumbled from "I'll use this library for these radio transceivers since operating them manually is hell" to "Huh, this example code doesn't work, let's fiddle with it" to "not only did I make the example code work, but I just figured out what's wrong with the library" in the span of about 2 hours.
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<UmbralRaptor>
\o/
<SnoopJeDi>
congrats Ellied, nice work!
<Ellied>
thanks!
<Ellied>
last commit was 9 months ago so we'll see if it ever gets pulled in, but still a personal milestone nonetheless.
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<SnoopJeDi>
I know the feeling, my first meaningful one was never merged, but it was still a big mental hurdle to get over
<Ellied>
I imagine nRF24L01+ use on RPis is not a very hot topic these days since the latest boards all have far more versatile integrated WiFi chips. On the other hand, the power use of the nRF compared to wifi is remarkably low (left one running today off a small battery, and it barely put a dent in it), so maybe they're still in use for some things.
<Ellied>
a lot of the open issues on this library are things I feel tantalizingly close to being able to solve. Maybe I should just open a proper fork.
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<Iskierka>
I was trying bluetooth first but I was thinking about that as a way to remotely talk to an rpi when a network may not be available. and switching over and setting up a hotspot on laptop would be a pain
<Iskierka>
though so far there's been little luck in getting bluetooth to support a terminal
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<Ellied>
Iskierka: I've heard of it being done, but I haven't had much luck figuring it out and bluetooth on linux is almost always pure madness
<Ellied>
My two weapons of choice for RPi interfacing are the USB console cable and the ad-hoc wifi network.
<Iskierka>
weirdly, it seems to actually work well on my laptop and I can connect to the pi. Just how to get a terminal is completely obscure even following several different guides (after exams going to try undo the main one and investigate more deeply)
<Iskierka>
in fact my phone is more annoying for bluetooth as it won't save the tethering setting long-term, so I can't just tell laptop to borrow its network for a moment. Need to get phone out and re-enable
<Ellied>
oh yeah my phone does that too, just ~magically forgets~ pairings after a while
<Ellied>
I think you have to edit cmdline.txt and add a console to the bluetooth serial interface, but I don't really know how to do that
<Iskierka>
remembers the pairing, just turns off tethering. Like, no, I want that on permanently, you're supposed to be sitting ready for requests
<Ellied>
oh, huh
<Iskierka>
the tutorials had me do something like that but I don't understand the system enough to know what was going wrong
<Ellied>
if you haven't got a USB console cable, you might consider one. They're cheap I think, and a pretty foolproof way of accessing a Pi's console even if it has no working network interface at all.
<Ellied>
all you need are the two serial UART pins and a ground pin on the GPIO header and you're in, provided enable_uart=1 is in config.txt
<Iskierka>
the wifi network does at least work at home so I'm experimenting here to try get the bluetooth working. Might not work elsewhere since I bound its IP on its end instead of the router, which I should also change
<Ellied>
I've had great luck with ad-hoc. It doesn't require much configuration so it's easy to have the Pis just connect when they boot, and then they're all accessible to each other whenever they're in the same room. Plus they all have consistent static IPs.
<Ellied>
if you're using the wifi as an actual internet connection a lot it's probably less than perfect though
<Iskierka>
I might consider that if you can make sure the ad-hoc is private, since the other bluetooth problem is configuring it in a way you're sure new pairing is disallowed
<Iskierka>
I do tend to be, yes :p
<Ellied>
I haven't looked into setting up encryption/authentication yet, I've heard that's hard for ad-hoc networks.
<Ellied>
I've just been treating it like it's the wide open internet anyway, so all the security is at the doorsteps (RSA auth only, nonstandard port, etc) instead of before the network.
<Ellied>
when I'm on my uni's network, I *am* on the wide open internet, so those steps are necessary anyway.
<Iskierka>
true, the bluetooth vulnerability is that it just ties a bluetooth console straight onto the auto-login one
<Iskierka>
and then if it's not on auto-login it might also not auto-perform things needed to actually provide it and glhf starting it up
<Ellied>
I think bluetooth is already designed to be pretty secure. You have to be pretty explicit about allowing new pairings from the device end, right?
<Iskierka>
In cases. It does currently appear to still accept new pairings, and idk what people may be able to figure out to make it accept it, so I'd rather figure out a no-new-pairings state that still allowed previously accepted
<Iskierka>
I did have mild success with just the straight USB gadget setup (mainly messing with a pi 0) so not sure if I need that as such, but I'll keep it in mind
<Ellied>
oh you have a zero, okay
<Iskierka>
serial is weird though. Have a GPS that uses serial which I couldn't get to read and unclear if it just wasn't locked or just refused to talk. Gonna go through in sensible order of making stuff work though, so the GPS is far down as a low precision sensor
<Ellied>
I mostly deal in 3s because that's what my prof has us buy for class, so usb gadget mode isn't an option
<Iskierka>
Have a 3B and a 0, 3B is sitting around as a server that can just stay on wifi with a dyndns server, 0 is one I plan to take around and want to be able to find digitally
<Ellied>
sure
<Iskierka>
Wanted a low power one that I can mess around with on battery a lot - but is definitely very low power so may consider swapping for another 3 as well
<Iskierka>
Just have to see where it leads *shrug*
<Ellied>
hmmm, maybe I should see if I can set up an nRF24 for console access.
<Ellied>
since they're so low-power that could be pretty useful
<Iskierka>
if I was going that route I'm not sure I'd do that unless it turned out to be quite easy, was just thinking I'd decide what I need and then use it as a communications relay for whatever instructions I decide on
<Iskierka>
but it *should* be easier to use the communications both devices already support, so
<Ellied>
yeah I'm just dreaming here
<Ellied>
bluetooth is a good idea for console access since it's already on-board but won't tie up the wifi
<Iskierka>
well, hopefully won't. Previous laptop even low-intensity bluetooth connections brought wifi below dialup speeds
<Iskierka>
though I'm not sure if that's just a badly supported machine or they've dramatically improved things, as pretty much everything works perfectly on the thinkpad
<Ellied>
I've had no trouble on my toughbook, although on the Pi having bluetooth audio streaming and wifi active at the same time makes it get stuttery because the antennae are so close together
<Ellied>
but that's audio. You hardly need an unbroken continuous stream for console access to work well.
<Iskierka>
Does the pi actually use separate antennae?
<Ellied>
good question. Now that you mention it I think not, which explains why streaming bluetooth simultaneously as using wifi works so badly. :P
<Ellied>
but I'm pretty sure on my laptop they do.
<Iskierka>
On both of mine they definitely don't. They're the same frequency so device-sharing is much cheaper to implement
<Iskierka>
though a decent wifi&bluetooth device may be good at presenting itself as two devices
<Ellied>
oh, now I know mine are separate. the wifi is a PCI device, but the bluetooth shows up in lsusb
<Iskierka>
interesting.
<Iskierka>
... windows what the fuck, 152 GB of temp files?
<Ellied>
thats rather a lot
<Iskierka>
that apparently includes downloads which I do not consider to be particularly temporary, though is 109 GB
<Iskierka>
I don't know why there's 35 GB in the recycle bin when I always shift-delete
<Iskierka>
and the previous version of windows, which I got here because it suggested I create space by deleting, is 5.5 GB. Iiii think I'll keep that as there's much more efficient ways to clear space that won't be deleting something I might want at some point
<Ellied>
can you still switch back? I thought they locked you after a month.
<Iskierka>
I still have the version there and old install disks so if they wanted to try stop me ... ¯\_(ツ)_/¯
<Iskierka>
hell I could run legit vista on this if I were crazy
<egg|work|egg>
!wpn Iskierka
* Qboid
gives Iskierka a protracted Brand New Photoneutronic Engine
<kmath>
<MicroSFF> "Human cultures have stupid, made-up, adult milestones, like lose virginity, kill a lion, get drunk. Do robots?" "Reject a software patch."
<egg|work|egg>
!wpn Ellied
* Qboid
gives Ellied an amphibious involution
<egg|work|egg>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor a radioactive killing nova-like paywall
<Iskierka>
they're really getting aggressive against adblock users now
<UmbralRaptor>
egg: This makes the idea of having xray/UV/optical/IR/microwave/radio instrumentation entirely too plausible.
<Thomas>
In before "Principia - The game"
<UmbralRaptor>
It feels like a significant chunk of KSP modding should be written up as MSc theses for aerospace engineering. >_>
<UmbralRaptor>
(I believe this has been explicitly said about FAR)
<pizzaoverhead>
Didn't Majiir say he'd get either a paper or a patent out of his method of tesselation for Kethane's grid?
<egg>
UmbralRaptor: nah, in principia's case it's more A&A material (at least the references are)
<pizzaoverhead>
egg: What's the camera code plan?
<egg>
~projective space~ (for the abstractions)
<egg>
pizzaoverhead: the reason is that we want to downsample to plot the trajectories
<egg>
so that we don't send a novel to the GPU at every frame
<egg>
to downsample it makes sense to do so based on the rendered points, so you show as many points as needed and not more
<egg>
therefore -> do the projection ourselves
<pizzaoverhead>
What way were you doing it previously?
<egg>
not downsampling
<egg>
plotting one point every 10 s
<egg>
lagging as hell :D
<egg>
(which means people just turn off the history display)
<pizzaoverhead>
:D
<soundnfury>
!wpn pizzaoverhead
* Qboid
gives pizzaoverhead a trellis power supply
<pizzaoverhead>
!wpn soundnfury
* Qboid
gives soundnfury a caramelized git
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<SnoopJeDi>
caramelized git...SVN?
<soundnfury>
it tracks one additional piece of inode metadata... the sticky bit
<SnoopJeDi>
I learned about `git commit --fixup` this weekend \o/
<SnoopJeDi>
and also the use of `:/` in a revspec to match commit messages
<soundnfury>
truly, git is majestic and deep
<pizzaoverhead>
egg: It would appear that in testing your camera behaviour, I broke the stock orbit renderer
<pizzaoverhead>
dT is NaN! tA: NaN, E: NaN, M: NaN, T: NaN
<pizzaoverhead>
SetVesselTarget fell over while I had Minmus targeted and transitioned into its SoI
<pizzaoverhead>
egg: You'll love this:
<pizzaoverhead>
While in orbit of Minmus
<pizzaoverhead>
You can target Minmus
<pizzaoverhead>
And the Mun, but not Kerbin
<egg>
...
<egg>
pizzaoverhead: well currently we don't have our camera, this will come in later versions (it will take time for us to have the pile of abstractions for that, and then to write the downsampling algorithm)
<pizzaoverhead>
Is Kerbin even targetable while interplanetary? o.O
<Ellied>
yeah, I think so? Last I played in 1.1 or so it was.
<Iskierka>
the targeting rules I've observed is can't target the owner of the current or a parent SoI
<Iskierka>
all others are fair game
<Iskierka>
so at mun mun, kerbin, and kerbol invalid
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<pizzaoverhead>
Iskierka, but at Minmus, Minmus and Mun are valid
<Iskierka>
I didn't think you can target your parent body?
<pizzaoverhead>
I tested it a few minutes ago. Yay consistency! \o/
<Iskierka>
is this just at minmus or is it generally you can target the parent, but not parent's parent?
<pizzaoverhead>
I only tested Kerbin, Mun and Minmus
<pizzaoverhead>
Kerbin: Can target Mun and Minmus.
<pizzaoverhead>
Mun: Can target Minmus
<pizzaoverhead>
Minmus: Can target Mun and Minmus.
<pizzaoverhead>
Though some of the GUI was falling over at the time...
<pizzaoverhead>
egg: That is the face that I am making while looking at code manipulating quaternions :D
<egg>
SO(3) is fun \o/ \o/
<egg>
SU(2) doubly covers fun
<egg>
\o/ \o/ \o/ \o/
<pizzaoverhead>
I don't even know which sphere I'm being ejected from any more :D
<pizzaoverhead>
Then I realised that I had neglected the existence of another reference frame in which the problem was taking place :D
<egg>
pizzaoverhead: playing principia?
<pizzaoverhead>
Back working on FreeIVA.
<pizzaoverhead>
Hadn't done any work on it since late 2015/early 2016
<egg>
aaah nice
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<pizzaoverhead>
Trying to add physical forces to a free-floating character in IVA, and have those forces affect how the camera controls work.
<egg>
\o/
<egg>
\\0//
<egg>
//o\\
<pizzaoverhead>
»8«
<pizzaoverhead>
For the targeting consistency, have you considered raising it with Squad?
<egg>
that way madness lies
<egg>
let me shun that
<egg>
no more of that
<pizzaoverhead>
I have had success on that front in the past with former Squad developers.
<egg>
*former* though
<egg>
pizzaoverhead: tbh, the whole celestial targeting thing is unneeded for us; it's just that it's convenient for other mods
<pizzaoverhead>
Though I'm not sure who actually works there these days. I'm sure Bob would throw in a reasonable request.
<egg>
pizzaoverhead: so I'm happy just ignoring its eggsistence
<egg>
trying to unify it even if anything could be targeted was kinda kludgy
<pizzaoverhead>
egg: Not going the "roll your own" route? I thought Principia was the bastion of NIH driven development :P
<egg>
so if I just ignore the celestial targeting and say "it's there for compatibility with less-enlightened mods" that allows our reference frame selection to stay simple enough that I understand it
<egg>
pizzaoverhead: well I may make a warp-to-plane alignment eventually
<egg>
or warp-to-<astronomical event here>
<egg>
we have the APIs for that, we know how to do it
<egg>
warp to next solar egglipse :-p
<pizzaoverhead>
Does Principia do nearest intercept point plotting?
<egg>
define intercept
<pizzaoverhead>
As I understand it, that and plane differences were the only reason for target plotting
<egg>
pizzaoverhead: principia has the LVLH frame
<pizzaoverhead>
"Intercept" in the KSP form, meaning "Not actually an intercept, but the closest point between two orbits"
<egg>
so it shows nodes (intersections of the LVLH reference plane) and closest approaches
<egg>
in the LVLH frame only
<egg>
so a frame which fixes the target
<egg>
like they do in real life fwiw
<pizzaoverhead>
"Closest approach", that was the term I was looking for
<regex>
I gotta boot that up again, been burnt out on the usual stuff...
<egg|df|egg>
regex: someday we should do dreary kerbin
<egg|df|egg>
!wpn regex
* Qboid
gives regex a Schwarz pulsed FPGA
<regex>
Someday...
<egg|df|egg>
Sigma88: so, quick update on my thoughts on that leap year thing; the scheme we described last time works, but it doesn't give you leap years of the form (leap once every k years except (once every kl years except (once every klm years except (once every klmn years ...)))) that you get e.g. in the gregorian calendar (instead you leap every 4 years, except sometimes you get 5 years between leap years). it would be
<egg|df|egg>
really nice to have that nested exception approach; I can think of a way of doing that with continued fractions (it won't actually give you the gregorian calendar though; what it will give you is once every 4 years except once every 116 years except ... because it turns out that's better)
<egg|df|egg>
Sigma88: I'll give you details on how to do that some other day
<Sigma88>
egg|df|egg: cool thanks
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<oeuf>
UmbralRaptor: one of my scholars is teaching another about disease and fouled water
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<UmbralRaptor>
egg|df|egg: Sanitation?
<egg|df|egg>
apparently
<UmbralRaptor>
egg|df|egg: Also, dreary kerbin?
<egg|df|egg>
an idea regex had, the KSP system with realistic densities
<Iskierka>
so kerbin would be super floaty?
<egg|df|egg>
the star is still a star iirc
<egg|df|egg>
but much dimmer
<egg|df|egg>
hence the name
<SnoopJeDi>
the sun is a mass of incandescent gas ♫
<UmbralRaptor>
Realistic densities, so Jool becomes a mini Venus, and everything else is an airless rock?
<egg|df|egg>
UmbralRaptor: yup
<egg|df|egg>
UmbralRaptor: and iirc the star gets heavier and so in-system Δv is such that you want RO (regex, am I remembering right?)
<Iskierka>
... the star gets heavier?
<UmbralRaptor>
Kerbol has a density of ~234 kg/m^3 for some reason.
<egg|df|egg>
UmbralRaptor: that's something principia can predict (tidal locking otoh it can't)
<egg|df|egg>
also my craftdwarves are very good at making armor out of mussel and pond turtle shells
<UmbralRaptor>
Dreary Kerbin sounds like a great troll mod. But then, regex does lots of clever trolling.
<UmbralRaptor>
Hrm. What's Kerbol's [Fe/H]?
<UmbralRaptor>
<_< >_>
<egg|df|egg>
my archers are going to be dressed in really fancy silly outfits
<UmbralRaptor>
egg|df|egg: kappa armor!
<egg|df|egg>
UmbralRaptor: kappa?
<UmbralRaptor>
turtle IIRC
<regex>
Basic idea of Dreary Kerbin was that we use the radii and SMA in the game as fact but adjust everything's density to be realistic, yes.\
<UmbralRaptor>
...wait, why am I using a table for red dwarf sizes, Teff, etc? I have scaling laws listed in my paper collection (Beatty & Gaudi 2015).
<UmbralRaptor>
regex: This sounds like a fun troll mod. (But, uh, where do you launch from? Jool?)
<regex>
egg worked out the solar irradiance and Kerbin, even though within ?Mercury's? orbit was about like being on Mars
<regex>
UmbralRaptor, no, you launch from the Ceres-analogue Kerbin. :)
<regex>
It takes you nearly 6km/s to transfer to Duna
<egg|df|egg>
regex: UmbralRaptor just did the irradiance calculation above too :-p
<regex>
OTOH, launch only costs a few hundred m/s
<regex>
Oh nice.
<UmbralRaptor>
regex: Seems a bit hot for Ceres. (Though I suppose an argument could be made for a later M star?)
<regex>
I just skimmed. I think someone else tossed the idea out and we just ran with it. I had an RSS config for it but I lost it, would be much easier to make using Kopernicus.
<regex>
UmbralRaptor, more the density/mass.
<UmbralRaptor>
Fair enough.
<regex>
Actually i think I placed it more in the Mars density range.
<regex>
Anyway, Jool becomes a cold "Super Earth" with a few satellites, etc...
<regex>
although tbh I think it'
<regex>
s smaller than Earth?
<Iskierka>
does it become landable?
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<regex>
lol it is.
<Iskierka>
... less escape velocity too
<regex>
yes Iskierka, since a gas giant won't form that small, IIRC
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<UmbralRaptor>
Jool's marginally smaller than Venus IIRC.
<Iskierka>
though from kerbin anything capable of LEO from earth can land that on Tylo
<Iskierka>
6000 km radius, I don't think venus is quite that close to earth?
<UmbralRaptor>
!wa venus radius km
<Qboid>
UmbralRaptor: convert Venus | average radius to kilometers: 6051.9 km (kilometers)
<Iskierka>
... fair enough
<Iskierka>
+- 1km on wiki also which is impressive
<UmbralRaptor>
All hail radar mapping.
<regex>
I think it'd be a fun little place to tool around on but it wouldn't fly in the KSP community because the lack of spaceplanes.
<Iskierka>
I didn't mean radar mapping, I meant how round it is
<regex>
becasue literally nothing but Jool could hold an atmosphere
<regex>
and why would it have an oxygen atmosphere ?
<UmbralRaptor>
Traces are possible, especially if far UV and flares happen. Pretty hard for liquid water on the surface, though.
<regex>
Yeah, trace stuff for sure
<regex>
Pluto proves that
<UmbralRaptor>
Mars, even.
<regex>
none of those bodies are larger than Ceres though.
<regex>
Perhaps Eve might have a slight atmosphere but I don't believe it would be massive enough even with Earth densities.
<egg|df|egg>
Iskierka: yeah we noticed it when making the gravity model config for venus
<egg|df|egg>
J2 is as vanishing as it gets
<UmbralRaptor>
Hm. Eve is 1400 km in diameter.
<UmbralRaptor>
So between Ceres and Pluto. I'd assume a higher density, but...
<Sigma88>
!wa pluto diameter
<Qboid>
Sigma88: Pluto | average diameter: 2370 km (kilometers)
<regex>
well, the closer things are to Sol, the denser they tend to be, at least with rocky planets.
<Sigma88>
!wa ceres diameter
<Qboid>
Sigma88: 1 Ceres | average diameter: 952.4 km (kilometers)