[00:22] Laurenceb (n=laurence@host81-154-154-203.range81-154.btcentralplus.com) joined #highaltitude. [00:27] hi guys [00:31] yo [00:32] hello :P [00:32] whats up? [00:34] working too much [00:34] you? [00:34] construction work [00:35] painting skirting all day today, very boring [00:36] however.... I did get my results today [00:37] oh? [00:50] yeah, got a first [00:51] still can't believe it :P one of the papers was awful [00:51] brb [00:51] congrats man! [00:52] thanks [00:57] natrium42 (n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com) joined #highaltitude. [01:01] syntac (n=wade@adsl-68-79-22-191.dsl.emhril.ameritech.net) left irc: "leaving" [01:04] Ebola (n=Ebola@unaffiliated/ebola) left irc: ""Don't let worry kill you -- let the church help."" [01:06] flowolf (n=flowolf@unaffiliated/flowolf) left irc: "Leaving" [02:02] natrium42 (n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com) left irc: [02:10] natrium42 (n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com) joined #highaltitude. [05:05] natrium42 (n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com) left irc: [05:57] natrium42 (n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com) joined #highaltitude. [06:51] Simon-MPFH (n=simon@phantom.mpfh.co.uk) joined #highaltitude. [06:54] akawaka (n=akawaka@external.treyarch.com) left irc: Read error: 110 (Connection timed out) [07:05] Kornholijo (i=kornholi@c-f1f472d5.09-99-73746f40.cust.bredbandsbolaget.se) joined #highaltitude. [07:05] !! [07:06] Hello everyone :o [09:06] edmoore (n=edmoore@smtp.vorticity-systems.com) joined #highaltitude. [09:07] morning Laurenceb [09:07] and all [09:12] hi edmoore [09:13] how's it going? [09:13] vorticity-systems? [09:13] very good thanks [09:13] Laurenceb: work [09:13] cool [09:13] Action: Laurenceb googles [09:14] speaking of which, have you ever come across anything on magnus effect at high mach numbers? [09:14] nope [09:14] Sim time then [09:14] unfortunately all my fluid dynamics is atmosphere related [09:14] virtually [09:14] ie rossby/kelvin waves [09:15] inertia gravity oscillations ect [09:15] yeah gravity waves were new to me a couple of days ago [09:15] till I saw a column for them in the mars atmosphere database [09:15] I'd never thought of that before - very cool [09:15] I was watching some in the sky the other day [09:16] the pic on the front page looks appropriate XD [09:16] aye [09:16] that's the current fun [09:17] well I'll shortly be having fun installing skirting boards [09:17] Matt next to me has got some incfedibly beautiful high fidelity visualisations of the sims of the airbags landing on mars. I really didn't realise quite how good the simming tools available to industry were [09:18] what sort of software do you use? [09:18] written from scratch? [09:18] LS-DYNA for some stuff [09:19] scratch-built for most of the aerodynamics [09:19] right [09:19] the airbags are ls-dyna [09:20] oh you might now - is there something similar open source? [09:20] hmm [09:20] fraid not [09:21] well I mean I wouldn't know [09:21] got my results through yesterday [09:23] still cant believe it - got a first [09:25] oh awesome [09:25] well done [09:25] so you're sorted then [09:25] yeah [09:25] thanks [09:26] the scaling on the papers seems to have been crazy [09:27] 81% for my worst paper where the raw mark must have been <50, and 70% for my best paper where I was hoping for 80% [09:27] ? [09:28] lol [09:28] such is life [09:29] its not really fair... but at least I cant complain [09:31] when does sstl start? [09:31] 1st of october [09:33] wprking over summer? [09:33] well if you call installing skirting work, then yes [09:34] I'll have to take some photos, its looking good now [09:34] almost ready for decorating [09:34] balloons? [09:35] hopefully [09:35] just have no time atm [09:35] been working 12 hour days :S [09:36] I was up till 3am on monday installing an independent framing system [09:37] the whole thing is horrendously complex for a renovation project [09:38] when will it be finished? [09:38] about a month [09:39] then balloons! [09:39] yep :D [09:39] right I have to head off and get the skirting installed, cya [09:40] enjoy the work, sounds good fun [09:43] Laurenceb (n=laurence@host81-154-154-203.range81-154.btcentralplus.com) left irc: "The day microsoft make something that doesnt suck is the day they make a vacuum cleaner" [09:52] fnoble (i=81a90a38@gateway/web/ajax/mibbit.com/x-3776235ad7141b70) joined #highaltitude. [09:52] hi [09:52] edmoore: you around? [09:52] yo [09:52] finally got some crappy browser based irc client working [09:53] lol [09:53] hows things? [09:53] it's a tough life [09:53] are you in EIEIO? [09:53] no, the DPDPO [09:53] ok, looking at magnus effect at high mach numbers [09:53] I have an unsimmable thing to sim [09:54] sounds good! [09:54] took the badger for a walk the other day [09:54] got a gps log saved onto the SD card [09:54] :) [09:54] awesome [09:54] so the gps was just an endia fix? [09:55] endian* [09:55] yeah, a wierd one [09:55] would be boring if it wasn't, frankly [09:55] need to fix it properly [09:55] just swapped the byte manually for now [09:55] yucky poo fergus [09:55] btw, are you still planning on coming up at the w/e? [09:56] i have been having this exchange on email [09:56] and getting unhelpful answers from jen [09:56] is there stuff happening? [09:56] well, ears is cancelled as you probably know [09:56] cos I mean, the dept probbly isn't open is it [09:56] yes yes yes [09:56] will people stop telling me that [09:56] heh [09:57] sorry, i havnt really been checking my emails much [09:57] I would defintely be coming if there was an ears [09:57] I'd still like to, but it depends on what there is to do [09:57] anyway, me, iain and rob will probably be working on stuff [09:57] whatcha working on that can be done at weekends? [09:57] i.e. is the autoclave room open and stuff? [09:58] well we still have the IFM room at the weekend [09:58] well we dont have anything to make in the autoclave yet [09:58] will mainly be coding and electronics [09:58] so mainly tronics? [09:58] yup [09:58] ok - do you want to maybe start on v1.2? [09:58] or is there still plenty to be doing on v1.1 [09:58] will probably take ages to get this mould [09:59] i think we are nearly ready for 1.2 [09:59] the only thing i want to have more of a look at is the telit [09:59] so could come and have a bash at that [09:59] yeah, sounds good [09:59] we can do them in parallel [09:59] i will bring up the telit test board [09:59] i guess you can get the megabus now you dont need to drive [09:59] cool [10:00] and we needed and farking svn. let us get all of badger on google code [10:00] and we will provide brunches [10:00] or else [10:00] yup, ok [10:00] that way I can do stuff too whilst stranded abroad [10:00] in forein climbs [10:00] its anoying we have been denied internet access on our dev machine :( [10:00] does your new room look out onto the anchor? [10:01] no, onto a bit of kings and a bike shed [10:02] that's no use [10:02] if telit works we should launch something next weekend or something [10:02] yeah, deffo [10:02] oh oh oh, we could try and get a radio working on avr [10:02] i was going to ask about that [10:03] there might be an arguement for having one of them working before 1.2... though actually the hardware probably won't go wrong [10:03] he says.... [10:03] yeah, it may be good to fly a steve radio as well if he is willing [10:04] since they are the most reliable design we have flown [10:04] we should be ordering some radiometrixs today [10:05] good good, we need a stock [10:05] well if we fly a steve, we need therefore to get a steve [10:05] and we need to sort out the 232/i2c interfacing issue [10:05] yeah [10:05] but its better than starting from scratch [10:06] we should get henry's code too [10:06] he is online curently [10:06] get him in here [10:06] that's even better than starting from scratch [10:06] i have no other means of communication [10:06] just re-write for an avr [10:06] ok [10:06] yeah [10:07] fnoble_ (i=81a90a38@gateway/web/ajax/mibbit.com/x-130c4c0e746a9941) joined #highaltitude. [10:07] ok [10:08] emailed him to ask him to appear [10:08] ok [10:08] oh my god he's up early [10:08] what time is it there? [10:08] fnoble (i=81a90a38@gateway/web/ajax/mibbit.com/x-3776235ad7141b70) left irc: "http://www.mibbit.com ajax IRC Client" [10:14] 5am? [10:14] sorry was chattin [10:15] s'ok [10:15] I have this nasty problem to analyse, to see if the parachute sabot, when its ejected, will recontact with the pilot parachute [10:15] and it's a flat plate being flicked out as the chute package flicks over 180 degrees [10:16] so it's sort of magnus effect of a complex shape in high mach on mars. It's a bit beyond 1A. [10:16] infact... is Iain there? [10:17] yup [10:17] ill get him, i have no idea what you are talking about :) [10:18] what's a sabot for one! [10:18] this is Iain now btw [10:18] the thing that sits behind anything you eject from a barrel [10:18] the sort of gas seal thing [10:19] http://en.wikipedia.org/wiki/Sabot [10:19] so this is a circular in cross section, but I-shape if you can across it [10:19] and it's being flung out spinning into a mach 3 flow [10:20] right.. [10:20] and the resulting magnus effect needs modelling, so make sure it doesn't fly into the chute or something crap like that [10:20] that sounds tricky [10:20] so it's basically magnus of spinning plates in supersonic flow [10:21] will it split so it's not actually a plate but two halves [10:21] no, it's one solid plate [10:21] Ok [10:22] the cable is wrapped around the chute, and the sabot is a snug fit to the chute, it sort of craddles the bottom half [10:22] Will it definitely remain axial, or could it twist, as that would make it much more difficult [10:22] so when the chute gets flung out the mortar, and the cable becomes taught, it snaps the sabot off [10:22] and the sabot starts spinning round [10:24] because of a torque generated by it being prized off by the cable going taught. But don't worry - we will put it in the sim and get completely untrustworth results [10:24] Is the whole para =sabot thing ejected with spin, or does it spin after? [10:24] but ESA might trust them [10:24] the para is loaded into the mortar head first [10:25] so it flicks over 180 degs when it opens [10:25] this is massively confusing to visualise [10:28] the magnus effect only does stuff when the flow is perp. to the circular cross section (right?) otherwise t=you just have a circular flat plate in the flow [10:28] so are you trying to model it in the flipping round phase? [10:29] 2 secs [10:38] sorry, am back [10:38] was white-boarding with shane [10:41] so the plate will be ejected by the mortar and chute arrangement with some horizonal velocity v, some angular velocity w [10:41] into a flow of velocity u [10:41] mach 1.9 [10:41] it's not that exciting - I'll keep reading [10:42] and at this point the axis of rotation of the disc is horizontal?? [10:42] yes [10:42] now I understand! [10:42] so it's spinning about that axis, like tossing a pancake [10:44] the direction of spin is in fact such that the magnus effect should result in a force such that its vector points away from the entry module [10:44] that sounds like patching a subsonic b-layer onto an external supersonic flow field, which may take a while! [10:44] but I'd still like to be a bit more quantitative [10:45] flowolf (n=flowolf@unaffiliated/flowolf) joined #highaltitude. [10:45] what's the mold like? [10:45] mould* [10:46] Pretty awesome, we need to get info from the manufacturer to see if they can mill in it one piece [10:46] its about 1.5m long, external mould with latex balloon inflated inside [10:47] should get an awesome finish on the rocket [10:47] :D [10:47] I want to visit these peeps [10:47] It covers the nosecone and ~1m of tube [10:47] me too [10:47] have you not? [10:48] We should see if we can get a tour around [10:48] No just talked to them. I'm sure they'd be keen, but we'd need a car...(Ed?) [10:48] I should get back to Matlab and work out stability margins [10:48] Are they about at the weekend? [10:48] fun, fun fun [10:49] ok [10:49] well... do what fergus has done [10:49] and log into irc [10:49] then check every 2 hours when you need a break from matlab [10:49] and that's how irc works [10:49] he not cool enough for irc [10:50] fergus again? [10:50] yup [10:50] crossworks is being so annoying [10:50] its full of bugs this beta mac version [10:51] sigh and arse [10:51] if you feel crazy, could try Code::Blocks [10:51] but then we don't have the fast maths lib [10:51] wonder if there is a newer version- could you give me the download link? [10:51] but it's got a GUI for GDB [10:51] will have a look - gimme a sec [10:52] http://www.rowleydownload.co.uk/snapshots/msp430_crossworks_wavefront_macos_ [10:52] x86.dmg [10:52] that should all be one line [10:53] jcoxon (n=jcoxon@92.40.215.159.sub.mbb.three.co.uk) joined #highaltitude. [10:53] msp430? [10:54] change that to arm, too [10:54] hi jcoxon [10:55] jcoxon: hello! [10:55] alright all [10:56] hows tricks? [10:56] ok, good progress with the flight computer [10:57] excellent [10:57] got it logging gps to an sd card [10:57] coolio [10:57] ready to fly!! [10:57] really... [10:57] no [10:57] hehe [10:57] need radio and telit still [10:57] oh fnoble_ I've put badger v1.1 forward to a high alt attempt [10:58] just thought you should know.... [10:58] :-D [10:58] edmoore, a little bit of balloon porn for you: [10:58] http://www.flickr.com/photos/jcoxon77/2634900584/ [10:58] well, just make a light payload, put it under a 1.2 on a still day and see what happens [10:59] oh james! [10:59] that's a beautiful! [10:59] i've also got it now to grab sms of my phone via bluetooth when they arrive [10:59] fnoble_: was it wxwidgets you got excited about at the end of last term? [10:59] hallam (i=hallam@PIKA-ONE-TWENTY-ONE.MIT.EDU) joined #highaltitude. [10:59] next step is to set up the packet radio decoder [10:59] hey gang [11:00] and work out a way of getting hte data accross [11:00] hey henry [11:00] erm, well yes and no [11:00] fnoble_: I've been using it, that's all. And now can share the excitement, if there's any to be shared [11:00] i was getting excited about how you can wrap wx really nicely in python [11:00] And given rob F and Iain are windows trogolodytes [11:01] would be useful for all our stuff to be portable [11:01] yeah [11:01] hey henry [11:01] Action: hallam reports for brain picking [11:01] be gentle though, it's 6am here [11:01] fnoble_: fire away, need to do some code for 2 mins [11:01] hallam: got up early or not slept yet? [11:02] latter [11:02] borism_ (n=boris@195-50-207-110-dsl.krw.estpak.ee) joined #highaltitude. [11:02] http://www.spaceref.com/news/viewpr.html?pid=19911 this suggests that Ola is a promising sort of person [11:03] I'll see if I come across him [11:03] And make friends if i do [11:04] henry: could we have a look at your radio code / hardware design? [11:04] flowolf (n=flowolf@unaffiliated/flowolf) left irc: "Leaving" [11:04] sure [11:04] it's essentially unchanged since Nova 3 [11:05] hallam: we basically want to plonk it onto an avr. Although actually a pic could be used [11:05] advantage of the PIC is the built-in 4-bit DAC which I believe the AVR doesn't have? [11:06] correct [11:06] but we do have some external Dacs [11:06] ok [11:06] personally I would choose a PIC over an external DAC [11:06] and only the massive pics have the DAC? [11:06] no [11:06] I think even some 8-pin PICs have it [11:06] ok, thats cool then [11:07] don't think the 8-pin ones have a UART but you can get pretty small ones that do [11:08] The DAC on them is just generated off the pwm though isn't it? [11:08] no [11:08] not that that's inherently a bad thing [11:08] it's a real DAC [11:08] it was designed in to provide a reference for the comparator [11:08] but you can use it just fine as a DAC [11:09] ok [11:10] it's an R-2R ladder I believe [11:10] hallam: could you email the firmware zip to fergus and I? [11:10] ok lemme find it [11:10] hallam: is all MIT rocket money dried up? [11:10] or at least, you've lot it? [11:10] lost access to it* [11:11] um, not that I'm aware of, there are still a few thousand in the account for this year [11:11] borism (n=boris@195-50-197-65-dsl.krw.estpak.ee) left irc: Read error: 145 (Connection timed out) [11:12] there's a shop set up to sell paparazzi modules which sells 10 ublox 5H's for $380 [11:12] i.e. �20 each [11:12] which is amazing as they're one of the best GPSes on the market [11:12] does it include an antenna? [11:12] email sent [11:12] thanks [11:13] the pic lets you connect your own reference to each end of the ladder [11:13] so I have a couple of pots [11:13] that lets you tune the frequency and the shift [11:13] for the software, there are a couple ways to do it [11:13] I recommend having a dedicated microcontroller of some kind for the radio [11:13] hallam: no it's just the pcb module [11:13] but making up pcbs is not too scary [11:13] we are [11:14] surface mount module* [11:14] sure [11:14] but it means an external active antenna which is annoying to provide power for, or a patch antenna and an LNA which is a hassle [11:14] but we can then make pcbs for just the gps, stick em on a can bus, and mount them whevever [11:14] fair enough [11:15] and can have 50mm x 50mm pcb ground planes with a 25mm patch antenna [11:15] and have about the best lock money can buy [11:15] by that point it probably ends up bigger and heavier and expensiver than an EM406 [11:15] but may well be worth it for the better reception [11:15] and works about 24km [11:15] and has 5hz updates [11:15] 4hz* [11:15] how sure on the altitude? [11:15] the 5H works above 24km? [11:15] uhuh [11:16] sure in that I spoke to a swiss engineer who couldn't really do enlgish [11:16] while the data sheet says yes, no one has actually pushed it [11:16] none of my ubloxes have reached 24km [11:16] but kept saying 'just 515m/s limit. dynamic limit. no altitude limit' [11:16] that's fairly promising [11:16] we should test them [11:17] if they work, they'll be groovy [11:17] well i've got one nearly ready to fly [11:17] cool [11:17] for rocket purposes it would be good to know exactly what it does when the dynamic limit is exceeded too [11:17] brb [11:17] need to get it high [11:17] well we should log iain's l2 for next month [11:17] we have the time to do that now [11:17] anyway back to the software, assuming you want to do the cos pulse shaping, you can either chop up the waveform along the time axis or along the voltage axis [11:18] fnoble_: for when you get back: we should make a ublox logger for iain's l2 [11:18] time axis is the traditional way, voltage axis is better [11:18] I'm not following you [11:18] I'll describe the dumb way first [11:19] at evenly spaced time intervals, you output a voltage looked up from a table [11:19] yup [11:19] so far so good [11:19] or vice versa? [11:20] output looks like 0 0 1 1 2 3 6 10 13 14 15 or something [11:20] so you totally waste the capability of the dac [11:20] yep yep [11:20] i see what the alternative is [11:20] ok [11:20] yeah, we can do it that way no probs [11:20] I'm sure in practice it makes fuck all difference to the radio [11:20] it's nice to be nice [11:21] and I bet in practice you don't need a DAC at all, and would be fine with a UART connected to a first order passive filter [11:21] you are almost certainly right [11:21] but I did it with the DAC and the 'clever way', that's what's in the firmware I sent you [11:21] but then you can't try something different when you want to get clever [11:21] iain asks how heavy do you expect the parachute and harness to be? [11:22] asks me? [11:22] for the 100km rocket? [11:22] yep [11:22] iain is being politic.... [11:22] he knows, he's building the mofo [11:22] I guessed about 200-300g for my sims [11:22] based on some quick googling [11:23] what does he reckon? I'd love to know [11:23]