highaltitude.log.20090626

[00:01] <Laurenceb> looks like you can do orbit launching from 30Km with a two stage
[00:02] <SpeedEvil> wthis is a minimal mass attempt?
[00:02] <Laurenceb> first stage peroxide/kerosene with liquid methane pressurization, second stage a solid fuel L class
[00:02] <Laurenceb> yeah
[00:02] <Laurenceb> 37Kg GLOW
[00:03] <Laurenceb> but it needs liquid methane pressurization
[00:03] <SpeedEvil> are you just doing a stupied delta-v, or actual orbital machanics
[00:03] <Laurenceb> orbit mechanics with drag
[00:04] <Laurenceb> atmospheric model up to 86Km then a look up table
[00:04] <Laurenceb> and some data from flight tests or various bodies at different mach numbers
[00:04] <Laurenceb> with a safety factor of 4
[00:04] <Laurenceb> its all in matlab
[00:05] <SpeedEvil> what orbit does it end up in?
[00:05] <SpeedEvil> and what's the mass of the solid?
[00:05] <Laurenceb> launch at 30Km with a gravity turn, then fire the solid at apogee at ~240Km
[00:05] <Laurenceb> 2.8Kg
[00:06] <Laurenceb> of the shelf L class motor wrapped in thermal blancket thats epoxied on, then put in a CF tube
[00:06] <SpeedEvil> how much is the solids dry mass?
[00:06] <SpeedEvil> ah
[00:06] <Laurenceb> 0.5Kg
[00:07] <SpeedEvil> you just spin it, and accept the stupid-G
[00:07] <Laurenceb> 50cm long, and 70mm diameter
[00:07] <Laurenceb> yeah, launched out of a plastic tube
[00:07] <SpeedEvil> I'd wonder somewhat about the solid standing up under high G near burnout
[00:07] <Laurenceb> with some rifling using blades mounted in the nozzle retainer
[00:08] <SpeedEvil> I suppose if it's spinning at 10000RPM, that'll help press the propellant to the case :)
[00:08] <Laurenceb> more like 1000 max
[00:08] <SpeedEvil> yeah
[00:09] <SpeedEvil> Not serious.
[00:09] <Laurenceb> one issue with this is pointing
[00:09] <Laurenceb> I worked out that two flywheels could be very light
[00:09] <SpeedEvil> 'To infinity and beyond!'
[00:09] <Laurenceb> on the first stage
[00:10] <SpeedEvil> As can magnetorquers - but I don't think that'll quite cut it
[00:10] <SpeedEvil> works well for a cubesat tho
[00:10] <Laurenceb> you need to have very accurate pointing when you fire the second
[00:10] <Laurenceb> it has a 20gram payload :P
[00:10] <SpeedEvil> not good
[00:10] <Laurenceb> might be able to get away with 100
[00:10] <SpeedEvil> As a 1% weight growth...
[00:11] <Laurenceb> yeah, a serious second stage would get you lots more
[00:11] GeekShadow (n=Antoine@reactos/tester/GeekShadow) left irc: "The cake is a lie !"
[00:11] <Laurenceb> in fact peroxide/kerosene seems to work best with four stages
[00:11] <Laurenceb> erm 3 even
[00:11] <SpeedEvil> It's annoyign that there is this pesky requirement to do the accelleration in a few hundred seconds.
[00:12] <SpeedEvil> It'd be so easy if you could do it over a few hours
[00:12] <Laurenceb> with approx 48%, 24%, 28% mass distribution
[00:12] <SpeedEvil> (something like massively expanded gas thrusters, powered by boiloff, pulsed every few seconds)
[00:12] <Laurenceb> I wrote script to optimise a generic rocket with isp ~220
[00:13] <Laurenceb> you can have >2% payload with those specs (He cylinder pressurization and CF tube construction)
[00:14] <Laurenceb> yeah the airship idea takes about 30 minutes, but that can work due to the crazy ISP and residual lift
[00:15] <Laurenceb> once youve done two stages to clear the atmosphere, a slow durning third is actually best
[00:15] <Laurenceb> taking up to an hour to burn
[00:16] <Laurenceb> hence why I can up with the design using monoprop peroxide, unfortunately the low isp take you to under 1% mass fraction
[00:18] <SpeedEvil> I was wondering elsewhere a while back if you can meaningfully do fuel in the peroxide
[00:18] <SpeedEvil> for example, a polythene bead/peroxide slurry
[00:18] <Laurenceb> methanol peroxide works apparently...
[00:19] <Laurenceb> it just had the problem that it explodes if your not careful
[00:19] <SpeedEvil> I don't like miscible probs
[00:19] <SpeedEvil> pprops
[00:19] <SpeedEvil> for that reason
[00:19] <SpeedEvil> hence the thought of the solid
[00:19] natrium42 (n=alexei@74.198.8.70) joined #highaltitude.
[00:19] <SpeedEvil> much higher barrier to ignition
[00:19] <Laurenceb> yeah
[00:20] <Laurenceb> injectors dont work :P
[00:20] <SpeedEvil> that's a problem, yes
[00:20] <SpeedEvil> though I'm not sure that's true
[00:20] <SpeedEvil> paint sprayers work ok
[00:21] <Laurenceb> oh you mean really small particles
[00:21] <Laurenceb> interesting
[00:21] <Laurenceb> well lithium borohydride pwder works apparently :P
[00:22] <Laurenceb> in fact it has the higherst energy density of any known fuel
[00:23] <swilly> Laurenceb, did you ever test out those sparkfun radio modules?
[00:23] <Laurenceb> yep
[00:23] <Laurenceb> but I wasnt able to set up a free space test
[00:24] <Laurenceb> so I guesstimated between 5 and 100Km range
[00:24] <Laurenceb> its limited by the lame rx/tx control in the firmware
[00:24] <Laurenceb> if its not receiving a valid transmission, it ges to tx mode
[00:25] <Laurenceb> it wouldnt be too hard to reverse engineer the schematic for the modules then write some decent firmware for them
[00:25] <swilly> cool
[00:25] <swilly> thanks
[00:26] <Laurenceb> id guess at least 30Km with a yagi
[00:27] <swilly> do you drive pins high/low to switch rx/tx modes? I haven't looked at the modules all that closely.
[00:27] <Laurenceb> no
[00:27] <Laurenceb> it tried to work out stself, and fails
[00:28] <swilly> strange
[00:28] <Laurenceb> http://www.ismichaeljacksonalive.com/ <- lmao
[00:30] <natrium42> too soon
[00:34] <swilly> lol
[00:34] <swilly> i have a site like that
[00:34] <swilly> it will be the most popular website on the internet (hopefully) for approximately 15 seconds
[00:34] <swilly> http://isit2010yet.com
[01:09] edmoore (n=ed@88-202-192-1.rdns.as8401.net) left irc:
[01:22] swilly (n=swilly@adsl-226-199-167.gsp.bellsouth.net) left irc: Remote closed the connection
[01:31] <Laurenceb> http://imagebin.org/53684
[01:31] swilly (n=swilly@adsl-226-199-167.gsp.bellsouth.net) joined #highaltitude.
[01:31] <Laurenceb> ^ SpeedEvil: thats with a spun solid second stage
[01:32] <Laurenceb> 30km balloon launch
[01:41] <SpeedEvil> Umm - height above ground and downrange?
[01:42] <Laurenceb> height above ground and number of loop iterations
[01:43] <Laurenceb> x scale is pretty meaningless, as the time step is variable
[01:43] <Laurenceb> so it launches from 30Km
[01:45] <SpeedEvil> ah
[01:45] <Laurenceb> so it goes into elliptical orbit
[01:46] <SpeedEvil> what's the orbital life like?
[01:46] <SpeedEvil> Oh
[01:46] <SpeedEvil> 200km
[01:46] <SpeedEvil> pretty good then
[01:46] <SpeedEvil> (as the descendig node altitude stays constantish till it's circular)
[01:48] <Laurenceb> 210Km
[01:48] <Laurenceb> thats assuming 230ISP on both stages
[01:49] <Laurenceb> the ceseroni L motors are 214 at sea level with the stock enclosure
[01:49] <Laurenceb> then theoretical for peroxide kerosene is around 300 to 310
[01:52] natrium42 (n=alexei@74.198.8.70) left irc: Remote closed the connection
[01:59] <Laurenceb> first stage dry mass 3Kg
[02:14] Action: Laurenceb wonders how hard it is to get liquid methane
[02:14] <SpeedEvil> I think going from LN2 is the easy way
[02:15] <SpeedEvil> Or just exhaust from a insulated cylinder - if the heat capacity of the cylinder isn't too high
[02:15] <Laurenceb> yeah, but its very heavy
[02:16] <Laurenceb> would be perfect for testing
[02:16] <Laurenceb> but its an extra 500 grams of mass
[02:17] <SpeedEvil> No, I mean take a gas cyl of methane, open the tap and run out 2/3
[02:17] <SpeedEvil> should get you close to liquid
[02:17] <Laurenceb> hmm
[02:17] <Laurenceb> theres the thermal mass of the cylinder
[02:18] <Laurenceb> another thing is the risk of an explositon with the peroxide, but theres a piston over it
[02:21] <Laurenceb> hmm with LN2 you could avoid the piston
[02:21] <Laurenceb> maybe 400 grams heavier... still a Kg of ullage gas seems a huge waste, thats heavier then the entire engine
[02:27] Nick change: KingJ -> kingj
[02:54] natrium42 (n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com) joined #highaltitude.
[03:36] Mogwie (n=johan@cpe-74-75-100-121.maine.res.rr.com) left irc: "This computer has gone to sleep"
[04:04] natrium42 (n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com) left irc: "My other car is a cdr."
[06:27] natrium42 (n=Alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com) joined #highaltitude.
[07:15] Simon-MPFH (n=simon@phantom.mpfh.co.uk) joined #highaltitude.
[07:39] natrium42 (n=Alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com) left irc: Read error: 110 (Connection timed out)
[08:26] Simon-MPFH (n=simon@phantom.mpfh.co.uk) left irc: "Leaving"
[08:31] Simon-MPFH (n=simon@phantom.mpfh.co.uk) joined #highaltitude.
[08:33] rjharrison (n=rharriso@gateway.hgf.com) joined #highaltitude.
[08:58] Laurenceb (n=laurence@dyres221-74.surrey.ac.uk) left irc: "The day microsoft make something that doesnt suck is the day they make a vacuum cleaner"
[09:04] icez (n=icez@unaffiliated/icez) left irc: Remote closed the connection
[10:06] Laurenceb (i=zeusbot@lister.antycip.co.uk) joined #highaltitude.
[10:07] <Laurenceb> hello
[10:14] <rjharrison> hi
[10:32] GeekShadow (n=Antoine@reactos/tester/GeekShadow) joined #highaltitude.
[10:36] <rjharrison> Laurenceb: Haveing chatted with SpeedEvil: yeasterday I'm struggelig to set the pins low on the avr when they are set up for output
[10:41] <Laurenceb> oh you cant
[10:41] <Laurenceb> theres no pull down resistors
[10:41] <Laurenceb> you can only make them active low or add a resisotr externally
[10:50] borism_ (n=boris@195-50-200-18-dsl.krw.estpak.ee) joined #highaltitude.
[10:50] Nick change: kingj -> KingJ
[10:53] borism (n=boris@195-50-201-218-dsl.krw.estpak.ee) left irc: Read error: 145 (Connection timed out)
[11:26] GeekShadow (n=Antoine@reactos/tester/GeekShadow) left irc: Read error: 104 (Connection reset by peer)
[11:49] edmoore (n=ed@88-202-192-1.rdns.as8401.net) joined #highaltitude.
[11:58] <Laurenceb> hi edmmore
[12:05] <edmoore> hi
[12:07] <Laurenceb> can I ask you about the martlet rocket
[12:07] <Laurenceb> how are you fitting the motor?
[12:08] <Laurenceb> its a standard "refill" cartridge thingy?
[12:09] <Laurenceb> bbl
[12:09] <rjharrison> Laurenceb: You are better off putting edmoore in the line
[12:10] <edmoore> ta
[12:10] <edmoore> standard refills, custom motor case
[12:10] Bertrix (n=Bertrix@94-225-132-78.access.telenet.be) joined #highaltitude.
[12:23] herabot (n=herabot@78.146.177.110) left irc: Read error: 110 (Connection timed out)
[12:25] jcoxon (n=jcoxon@host86-146-165-194.range86-146.btcentralplus.com) joined #highaltitude.
[12:26] <rjharrison> hey jcoxon
[12:26] <rjharrison> revising hard?
[12:26] <jcoxon> hey rjharrison
[12:26] <jcoxon> not doing to well today
[12:26] <jcoxon> hehe
[12:39] <jcoxon> hows tricks?
[12:45] <edmoore> hi jcoxon, good to see you
[12:45] <edmoore> I've popped home
[12:46] <edmoore> are you still in worthing?
[12:47] <jcoxon> edmoore, nah i'm in london
[12:47] <jcoxon> been back for a week
[12:48] <edmoore> h'ok
[12:48] <edmoore> and which 'xams are these?
[12:49] <jcoxon> my end of rotation exam is next week and then my 4th year OSCE (practical exam) the week after
[12:51] <edmoore> fun
[12:52] <edmoore> then a launch?
[12:52] <jcoxon> but of course!
[12:52] <jcoxon> how about you guys?
[12:54] Action: SpeedEvil is still snowed under with boring stuff. Doing a couple of hours of work in the garden, then veging with no energy for the rest of the day. Post viral fatigue syndrome is fun!
[12:56] <jcoxon> SpeedEvil, doesn't sound fun at all!
[12:56] <SpeedEvil> Not really.
[12:57] <SpeedEvil> Some days I'm more or less OK - can do a whole days work - others I can't get up any energy at all. And if I overdo it, I can go down for a couple of months at times.
[12:57] <SpeedEvil> But meh.
[12:58] <edmoore> jcoxon: badger cub will probably be the next flight
[12:58] <edmoore> + some testing of a new toy - casio ex+f1
[12:59] <SpeedEvil> is badger cub assembled yet - or not up to that yet?
[12:59] <edmoore> nooo
[13:00] <edmoore> still at design stage
[13:00] <SpeedEvil> thought so
[13:00] <edmoore> we won't be launching anything in the next couple of weeks, quite probably
[13:00] <edmoore> no flight computer
[13:00] <SpeedEvil> Are there any GPS modules that can be set to 50bps?
[13:01] <SpeedEvil> Though that would be a silly way to do things.
[13:01] <edmoore> i see your logic
[13:01] <edmoore> would be super-kiss
[13:01] <edmoore> but no, not as far as I know
[13:02] <edmoore> bbl lunch
[13:06] <jcoxon> oh wow that casio looks amazing
[13:06] <jcoxon> oops he is at lunch
[13:07] <rjharrison> jcoxon it does look good
[13:08] <rjharrison> Loks like hard wire though unless someones done a CHDK on it
[13:08] <rjharrison> WTF is badger cub
[13:09] <rjharrison> B VII
[13:09] <SpeedEvil> A really teeny badger
[13:10] <jcoxon> 'WTF" is quite expletive
[13:10] <jcoxon> :-)
[13:10] <jcoxon> badgercub is the successor to badger
[13:10] <jcoxon> i think it has more features though i'm not sure what its based on
[13:13] <rjharrison> Cool
[13:15] <rjharrison> I'm sure they could pull something interesting out if they felt inclined to do so. Esp. on the miniturisation stakes
[13:15] <jcoxon> hehe
[13:15] <rjharrison> Though I wouldn't fancy soldering it
[13:15] <jcoxon> fergus and ed are pretty hot at surface mount soldering
[13:16] <SpeedEvil> Surface mount isn't that scary.
[13:16] <SpeedEvil> As long as you've got the tools
[13:16] <SpeedEvil> And are willing to accept the inevitability of PCB
[13:16] <SpeedEvil> Possibly getting a PCB built
[13:18] <edmoore> back
[13:19] <edmoore> jcoxon: badgercub is more or less the same as badger
[13:20] <jcoxon> http://www.flickr.com/photos/jcoxon77/3662681108/
[13:21] <edmoore> just a bit smaller
[13:22] <edmoore> jcoxon: yours?
[13:22] <jcoxon> yeah
[13:23] <jcoxon> had it made by olimex
[13:23] <jcoxon> just an avr and a radiometrix
[13:23] <edmoore> nice
[13:23] <edmoore> v nice
[13:23] <jcoxon> the plan is either add a gps or add to pegasus to do the rtty work
[13:23] <edmoore> got a serial port interface?
[13:24] <jcoxon> yes
[13:24] <edmoore> cool
[13:24] <jcoxon> for pegasus it means that i can do sstv continously
[13:25] <edmoore> awesome
[13:25] <jcoxon> yeah i'm pleased
[13:26] <rjharrison> jcoxon: It might be worth dilling a couple of holes either side of the RF cable and puting a cable tie on to take the strain off the RM pins
[13:27] <jcoxon> rjharrison, to tell the truth its a little too close to the edge
[13:27] <jcoxon> hot glue wil solve that a bit
[13:27] <edmoore> :)
[13:28] <rjharrison> I have a nice SMA connector you could solder on if you liked
[13:28] <jcoxon> its okay
[13:28] <jcoxon> i don't like connectors
[13:29] <jcoxon> now i was thinking
[13:29] <jcoxon> if i was going to have 2 transmitters how to do the antennas
[13:30] <jcoxon> if i went for 2 ground plane antennas do they need seperated? or can they overlap
[13:33] <SpeedEvil> at diffeernt freqs?
[13:33] <jcoxon> yes
[13:33] <SpeedEvil> how different?
[13:33] <rjharrison> well i think they should be fine close I don't have a problem with this at home
[13:33] <jcoxon> 434.075 and 434.650
[13:34] <rjharrison> 434.650 434.075
[13:34] <rjharrison> hehe
[13:34] <SpeedEvil> If the antenna can cope with both freqs, you can use the same antenna
[13:34] <rjharrison> ooh cleaver
[13:34] <SpeedEvil> Umm.
[13:35] Action: SpeedEvil tries to remember the required circuitry...
[13:35] <rjharrison> clever even
[13:35] <edmoore> i think that might not be the best thing to do
[13:35] <SpeedEvil> 50R from each transmitter to a 25R to the antenna will work - there are better ways though
[13:35] <edmoore> i would try for separate antennas
[13:35] <edmoore> if nothing else it's some redundancy
[13:36] <SpeedEvil> Unless you seperate the antennas out significantly physically, you'll get coupling anyway
[13:36] <edmoore> you could maybe have a groundplane for sstv and an end-fired dipole for the telem
[13:36] <edmoore> the end-fire dipole can stick out of the top, like what steve has been doing recently
[13:37] <jcoxon> i don't mind having 2 ground planes really
[13:37] <jcoxon> if i base the payload on that concept
[13:37] <jcoxon> also i'm planning to dump the canon A60 (as its managed to die again) and use a nikon coolpix 2500
[13:38] <edmoore> we're after some more CHDK cams
[13:38] <jcoxon> i'm not using chdk though
[13:38] <rjharrison> The coax-dipole is good in that it can be attached to the payload strings and should be less likly to tangle or warble much on way down assuming clean para deployment
[13:38] <jcoxon> need remote capture over usb
[13:39] <gordonjcp> rjharrison: j-pole
[13:39] <gordonjcp> end-fed(-ish)
[13:39] <gordonjcp> has some gain, not much but some
[13:39] <jcoxon> also that coolpix is quite a bit smaller, only 2.1MP (as the transmitted image is a lot smaller) and also i might be able to store the data on its CF card as well!
[13:39] <gordonjcp> can be made out of floppy stuff because it'll just dangle
[13:41] <rjharrison> gordonjcp: I had a play with the j-pole not convinced of the case against the gp
[13:41] <rjharrison> edmoore: http://photography.shop.ebay.co.uk/items/Digital-Cameras__canon-a560_W0QQ_catrefZ1QQ_flnZ1QQ_sacatZ31388QQ_trksidZp3286Q2ec0Q2em282
[13:44] <jcoxon> oh well something to sort out in the future, need to sort out the new camera anyway
[13:44] <Laurenceb> hello
[13:46] <gordonjcp> rjharrison: ground plane needs a big rigid thing
[13:46] <jcoxon> hello Laurenceb
[13:46] <gordonjcp> rjharrison: you might also try a 3/4 wave groundplane to get a higher angle of radiation
[13:46] <edmoore> rjharrison: thanks
[13:46] <edmoore> we may end up just restocking with 560s
[13:47] <edmoore> but there might be some cool stuff floating around now with exciting features - dunno
[13:49] <jcoxon> steve might launch this weekend
[13:50] <edmoore> cool. Well i'm down in west sussex so can't really offer to listen, but g'luck to him
[13:50] <edmoore> what's he launching?
[13:50] <jcoxon> not sure
[13:50] <jcoxon> he mentioned it earlier this week
[13:50] <jcoxon> considering hte near perfect js conditions
[13:51] <edmoore> yeah
[13:52] <rjharrison> BTW jcoxon: I tilloks like you have redacted the picture. Is that the famous jcoxon black tape in operation
[13:53] <jcoxon> only so that the module has a bit more of an anchor on hte board
[13:53] <jcoxon> if not its held in place by those 4 weedy pins
[13:54] <rjharrison> Yep I'm going to put a clip on the next verison of icarus to hold the bugger in place
[13:54] <rjharrison> A small solder strip on the other side should do it
[13:54] <jcoxon> i've also got some electrical tap along hte bottom to stop its shorting on anything metal
[14:02] <jcoxon> bbl
[14:12] rjharrison (n=rharriso@gateway.hgf.com) left #highaltitude.
[14:28] Mogwie (n=johan@66.186.190.58) joined #highaltitude.
[14:30] Simon-MPFH (n=simon@phantom.mpfh.co.uk) left irc: "Leaving"
[16:51] <edmoore> jcoxon: ping for your return
[16:55] <Laurenceb> http://www.graphitestore.com/itemDetails.asp?item_id=3336&prd_id=26&cat_id=22&curPage=2
[16:56] <Laurenceb> edmoore: can I ask you about martlet?
[16:56] <Laurenceb> how are you mounting the solid motor?
[17:04] <edmoore> Laurenceb: can you be more specific
[17:05] <edmoore> we are using standard fuel grains in a case that is built into the rocket
[17:05] <edmoore> a custom carbon-wound job with ceramic lining
[17:05] <edmoore> after quite some time with UKRA, we now have permission from the safety committee to ground test this design
[17:07] <Laurenceb> I see
[17:07] <Laurenceb> so you overwrap the fuel wet?
[17:07] <Laurenceb> or its loadable?
[17:08] <edmoore> loadable
[17:08] <Laurenceb> neat
[17:08] <Laurenceb> whats the ceramic?
[17:08] <edmoore> wouldn't want to stick a loaded motor in the autoclave :)
[17:08] <Laurenceb> custom nozzle?
[17:09] <Laurenceb> heh, you could do wet layup
[17:09] <edmoore> it's alumina-based
[17:09] <Laurenceb> custom?
[17:09] <edmoore> custom nozle, yep. optimised for alt
[17:09] <Laurenceb> nice
[17:09] <edmoore> Laurenceb: you really want to read iain's report
[17:09] <Laurenceb> where did you buy the material from?
[17:09] <edmoore> his master thesis was analysis for this
[17:09] <Laurenceb> ah cool
[17:09] <edmoore> and I don't want to get RSI
[17:09] <edmoore> i'll get you the link
[17:09] <Laurenceb> do you use the tensile strenght of the nozzle liner?
[17:10] <edmoore> http://www.srcf.ucam.org/~cuspaceflight/websvn/filedetails.php?repname=CUSF&path=%2FMartlet%2FIain_Waugh_Project_Report_Release.pdf
[17:10] <Laurenceb> - I was thinking of the high strenght graphite materials
[17:10] Nick change: Fighter|sleep -> Fighter1405
[17:10] <Laurenceb> thanks
[17:11] <Laurenceb> I was thinking of a mrtlet like second spun stage for a hab launched peroxide kerosene rocket
[17:11] <Laurenceb> but its only borderline feasible
[17:12] <Laurenceb> have you made much progress with machining?
[17:13] <Laurenceb> still going for the air stabilised, guiderail launched design?
[17:13] <edmoore> we're buying our own cnc router next week
[17:13] <edmoore> that should speed up progress
[17:14] <edmoore> and the guidrail was the topic of conversation on the way back from oxford the other day
[17:14] <edmoore> still various opetions
[17:14] <edmoore> lots of talk of spin stabilisation
[17:14] <Laurenceb> wow
[17:14] <edmoore> but you know that, cos you've read the report
[17:14] <SpeedEvil> np: The Simpsons soundtrack - Monorail.mp3
[17:14] <Laurenceb> SpeedEvil: do you bittorrent mp3s or something?
[17:14] <Laurenceb> its nawt downloading :-/
[17:15] <SpeedEvil> I don't think it actually exists - unless someones sampled it :)
[17:15] <Laurenceb> "waiting for www.srcf.ucam.org"
[17:15] <edmoore> hrm
[17:15] <Laurenceb> edmoore: youh, active stabilisation is especially hard on a solid rocket like that
[17:15] <edmoore> it may actually be downloading
[17:15] <edmoore> that link takes me straight to the pdf
[17:15] <Laurenceb> so much accel ect
[17:16] <edmoore> Laurenceb: we're definitely not going down that road yet
[17:16] <Laurenceb> its not too hard really - especially with guidevanes
[17:16] <SpeedEvil> Laurenceb: works for me seemingly
[17:16] <SpeedEvil> though still loading
[17:16] <Laurenceb> but a solid vehicle like that and its orders of magnitude harder
[17:17] <Laurenceb> really horrible high accel, vibration, short burn time, ect
[17:19] <Laurenceb> that graphite rod I linked is pretty impressive stuff
[17:20] <Laurenceb> gtg, cya all
[17:21] Laurenceb (i=zeusbot@lister.antycip.co.uk) left irc: "Lost terminal"
[17:29] <jcoxon> hey ed
[17:29] <jcoxon> ping edmoore
[17:29] <edmoore> yo
[17:29] <jcoxon> hey
[17:30] <Fighter1405> Hey jcoxon :)
[17:30] <edmoore> just wondering if you could remind me what sort of slots you might have for a UKHAS bbq?
[17:30] <jcoxon> hey Fighter1405
[17:30] <Fighter1405> How ya doing?
[17:30] <jcoxon> edmoore, i'm pretty pretty much from 8thJuly till 26th
[17:30] <jcoxon> Fighter1405, good thanks, been working on my avr/radiometrix board:
[17:30] <edmoore> i want to know when you're free, not when you're pretty
[17:30] <edmoore> you're always pretty to me, james
[17:31] <jcoxon> Fighter1405, http://www.flickr.com/photos/jcoxon77/3662681108/
[17:31] <jcoxon> edmoore, oops
[17:31] <jcoxon> hehe
[17:31] <jcoxon> i thought you'd need that info as well
[17:31] <Fighter1405> Nice
[17:31] <Fighter1405> Working?
[17:31] <jcoxon> yes
[17:31] <Fighter1405> Great :p
[17:32] <jcoxon> though with a 350shift rather then 425
[17:32] <Fighter1405> Ah
[17:32] <jcoxon> its no problem really
[17:32] <Fighter1405> I've been experimenting some more, is it possible the pins are interfering with each other?
[17:33] <Fighter1405> With one of the two pins plugged in it gives one frequency, if I take it out and plug the other in it gives a different frequency
[17:33] <Fighter1405> But when I have them both plugged in they both give the same frequency
[17:33] <jcoxon> Fighter1405, you using potential dividers on each pin
[17:34] <jcoxon> ?
[17:34] <Fighter1405> Yes, leading to the same resistor
[17:35] icez (n=icez@unaffiliated/icez) joined #highaltitude.
[17:35] <Fighter1405> pin |----res----
[17:35] <Fighter1405> ops
[17:35] <Fighter1405> pin |----res----
[17:36] <Fighter1405> Mhh, can't draw diagrams on IRC ^^
[17:36] <jcoxon> hehe
[17:38] <jcoxon> Fighter1405, okay lets got back to basics
[17:39] <jcoxon> the aim of the resistors is to drop the voltage on the pins down to around 1.2
[17:39] <jcoxon> so instead of setting up a potential divider - follow the original system
[17:39] <jcoxon> but use more resistors as you are dealing with 5v instead of 3.3v
[17:40] <jcoxon> edmoore, you free to mess aroun with radios?
[17:40] <jcoxon> (if you've got your icom that is)
[17:40] <edmoore> i'm in west sussex i'm afriad
[17:40] <edmoore> otherwise I would be
[17:40] <edmoore> whatcha wanna do, ooi?
[17:40] <jcoxon> some form of HF
[17:41] <Fighter1405> jcoxon: pretty image for you :p http://f.imagehost.org/download/0124/circuit
[17:41] <Fighter1405> That's what I have
[17:41] <edmoore> shame, would be up for that
[17:42] <edmoore> oh poo, forgot to get SWR meter today
[17:42] <jcoxon> Fighter1405, you are missing a resistor surely on that
[17:42] sbasuita (n=sbasuita@unaffiliated/drebellion) left irc: "Leaving"
[17:43] <jcoxon> as a voltage divider you are 'tapping' the voltage between 2 resistors that are connected to ground
[17:43] <Fighter1405> Where's the missing resistor jcoxon?
[17:43] <jcoxon> oh wait its there - misread it
[17:43] <jcoxon> why not try it with seperate resistors
[17:44] <jcoxon> instead of linking it all together
[17:44] Action: jcoxon is not great with electronics
[17:44] <Fighter1405> And two wires going into TXD?
[17:44] <SpeedEvil> Fighter1405: hat's the circuit doing at the moment
[17:44] <Fighter1405> SpeedEvil, sending pulses but all at the same frequency
[17:45] <SpeedEvil> what's the square box aat the bottom?
[17:45] <jcoxon> thats another resistor
[17:45] <Fighter1405> Above Ground?
[17:45] <Fighter1405> 10k resistor
[17:45] <SpeedEvil> yes
[17:45] <jcoxon> edmoore, we should find an IRC whiteboard addon
[17:45] <Fighter1405> Sorry for my awful drawing ^^
[17:45] <jcoxon> its what #highaltitude needs
[17:45] <SpeedEvil> Fighter1405: take a voltmeter
[17:45] <SpeedEvil> Fighter1405: see what the output voltages are
[17:45] <edmoore> jcoxon: i was just gonna say that :)
[17:45] <SpeedEvil> That _should_ work
[17:46] <Fighter1405> Hang on, need to wire it back up from the previous day :p
[17:46] Laurenceb (n=laurence@dyres221-74.surrey.ac.uk) joined #highaltitude.
[17:46] <SpeedEvil> though it will be something like...
[17:46] <SpeedEvil> 1.25-1.35 or so
[17:46] sbasuita (n=sbasuita@unaffiliated/drebellion) joined #highaltitude.
[17:48] <Fighter1405> Want me to wire them straight to +ve or through the pins?
[17:49] <SpeedEvil> the normal way you had it setup
[17:50] <SpeedEvil> however - wiring to the supply volts instead of the micro will give an indication
[17:52] <edmoore> jcoxon: not sure if you've come across it, but I, for the first time, spent some money on some software - 'papers' - and it's great
[17:52] <edmoore> like an itunes for your pdfs
[17:52] <edmoore> with searching of all the major journals too
[17:52] <edmoore> really good pdf management tool
[17:52] <edmoore> best ¬20 I've spent for a while
[17:53] <jcoxon> i haven't come accross it
[17:53] <Fighter1405> Voltages seem to be worryingly high
[17:53] <jcoxon> unfortunately my learning has collapsed from papers down to using just textbooks - just too much informationn
[17:54] <edmoore> :)
[17:54] <jcoxon> Fighter1405, careful, don't attach it to the radio
[17:54] <Fighter1405> I did have it a second ago
[17:54] <SpeedEvil> stupid comment.
[17:54] <SpeedEvil> You're sure you know how to read resistor codes?
[17:55] Action: SpeedEvil blew stuff up a couple of times way back when
[17:55] <Fighter1405> Yes, I'm checking it against the values on the packets anyway
[17:55] <SpeedEvil> k
[17:55] <Fighter1405> yellow purple orange
[17:55] <Fighter1405> 47k
[17:55] <Fighter1405> red red red
[17:56] <Fighter1405> 2k2
[17:56] <Fighter1405> brown black orange
[17:56] <Fighter1405> 10k
[17:56] <Fighter1405> Yes?
[17:56] <SpeedEvil> yeah
[17:56] <Fighter1405> I seem to be getting a vout of around 4.2v though :s
[17:56] <SpeedEvil> also - breadboards are not 100% reliable - especially if old or abused
[17:57] <SpeedEvil> when you connect one 47K to 0, one to 5?
[17:57] <jcoxon> Fighter1405, whats Vin?
[17:57] <Fighter1405> 5v jcoxon
[17:57] <SpeedEvil> err
[17:57] <Fighter1405> SpeedEvil the 47k is to 5, the 10k is to GND
[17:57] <SpeedEvil> you have got two 47k?
[17:57] <SpeedEvil> one in series with 2k2?
[17:57] <Fighter1405> No just one for each pin
[17:58] <SpeedEvil> I mean - one pin has 47K, one 47K and 2.2K
[17:58] <Fighter1405> yes
[17:59] <jcoxon> Fighter1405, i think an good idea would be do work with one 'line'
[17:59] <jcoxon> attach that to the Vin = 5v and get it down to 1.2v
[17:59] <Fighter1405> Haha, I'm using my voltmeter wrong
[17:59] <jcoxon> by using the correct resistors
[17:59] <SpeedEvil> :)
[17:59] Action: Fighter1405 feels like an idiot now
[18:00] <Fighter1405> ok, so vout is .8v roughly for 1 pin
[18:00] <SpeedEvil> that sounds about right
[18:00] <Fighter1405> And the other pin is about .85v
[18:00] <SpeedEvil> .8, and .72 or so
[18:00] <SpeedEvil> oh - the other way
[18:00] <SpeedEvil> that's connecting one pin to 0, one pin to 1 each time?
[18:01] <SpeedEvil> s/1/5/
[18:01] <Fighter1405> Yes
[18:01] Laurenceb (n=laurence@dyres221-74.surrey.ac.uk) left irc: Remote closed the connection
[18:01] <SpeedEvil> That should be OK then.
[18:01] <Fighter1405> Also jcoxon, I'm not sure I had it wired up correctly before
[18:01] <jcoxon> oh right
[18:01] <Fighter1405> In the diagram you use pins 9 and 10
[18:01] <Fighter1405> in the code you use 9 and 11
[18:01] <jcoxon> hehe, fair enouh
[18:01] <jcoxon> you can change either really
[18:02] <Fighter1405> So I may well have had them wired into 9 and 10, but the code on 9 and 11 :s
[18:02] <jcoxon> those we only 'notes'
[18:02] <jcoxon> were*
[18:02] <Fighter1405> I'm going to try wiring it all back up again and see what I can get on my laptop now
[18:04] <jcoxon> okay
[18:07] sbasuita (n=sbasuita@unaffiliated/drebellion) got netsplit.
[18:07] grummund (n=grummund@unaffiliated/grummund) got netsplit.
[18:07] grummund (n=grummund@unaffiliated/grummund) returned to #highaltitude.
[18:09] <Fighter1405> http://f.imagehost.org/view/0501/Untitled_10
[18:10] <Fighter1405> Do those dots at the bottom show a frequency shift?
[18:13] <SpeedEvil> The waterfall is a graph.
[18:13] <SpeedEvil> It graphs time upwards, and frequency along the ways
[18:14] <SpeedEvil> That looks like you've got a 300Hz periodic noise source
[18:14] <SpeedEvil> Correction.
[18:15] <Fighter1405> How is the theoretical frequency shift calculated?
[18:15] <SpeedEvil> A 300Hz wide source of noise - centerd on about 3581.2
[18:16] <SpeedEvil> you're still getting lots of interference. I'd wonder about the AC supply
[18:16] <Fighter1405> What's the output voltage on a usb?
[18:16] <SpeedEvil> what bps is this?
[18:16] <Fighter1405> 50
[18:16] <jcoxon> 50
[18:17] <SpeedEvil> 5V
[18:17] <jcoxon> Fighter1405, you'll need to seperate the voltages a bit more
[18:17] <SpeedEvil> replace the 2.2 with a 4.7
[18:17] <Fighter1405> I already tried with 47k and 5k jcoxon :s
[18:17] <jcoxon> any change
[18:17] <SpeedEvil> Anyway.
[18:17] <jcoxon> ?
[18:17] <Fighter1405> using two 2.2ks
[18:17] <Fighter1405> Nope, not much difference if at all
[18:17] <SpeedEvil> I think that first you need to work out where that noise is coming from
[18:18] sbasuita (n=sbasuita@unaffiliated/drebellion) got lost in the net-split.
[18:18] <SpeedEvil> It could be as simple as the power supply is too low, and has ripple on - causing the gain of the reciever to vary drastically in sync with the mains
[18:19] <Fighter1405> Is this noisy? http://f.imagehost.org/view/0728/untitled2_3
[18:19] <jcoxon> Fighter1405, it really looks like you are getting 2 peaks
[18:19] <jcoxon> but they are really c
[18:20] <jcoxon> close together
[18:20] <Fighter1405> That's with just one pin plugged into 5v
[18:20] <jcoxon> what happens with 2?
[18:20] <Fighter1405> The other pin is disconnected there
[18:20] <Fighter1405> Plug both into 5v?
[18:20] <SpeedEvil> Fighter1405: disconnect/reconnect the resistor to 5v
[18:20] <SpeedEvil> it should shift by a kilohertz or more
[18:20] <SpeedEvil> while looking at the display
[18:21] <Fighter1405> What do you mean SpeedEvil? Disconnecting the 5v just leaves the TXD floating
[18:21] <SpeedEvil> the 10K pulls it down
[18:21] <Fighter1405> Ah true
[18:21] <jcoxon> Fighter1405, we want to see the jump between the two setups
[18:21] <jcoxon> as in you are supply 2 different voltages
[18:22] <SpeedEvil> and also it helps confirm which signal you're actually picking up
[18:22] <jcoxon> and we want to see the shift
[18:22] <SpeedEvil> as does powering/unpowering the radio
[18:22] <SpeedEvil> (the transmitter)
[18:22] <Fighter1405> http://f.imagehost.org/view/0978/Untitled3
[18:22] <Fighter1405> That's with neither pin connected
[18:22] <Fighter1405> Just the 10k pulling it to GND
[18:23] natrium42 (n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com) joined #highaltitude.
[18:23] <SpeedEvil> http://www.w1hkj.com/FldigiHelp/RTTYFSK.html
[18:24] <jcoxon> hey natrium42
[18:24] <natrium42> hi
[18:24] <SpeedEvil> turn on an off the transmitter, and see if you can see a signal appear and dissapear in the waterfall. Note the frequency
[18:26] <jcoxon> natrium42, when you off to italy?
[18:26] <Fighter1405> http://f.imagehost.org/view/0852/Untitled4
[18:26] <Fighter1405> SpeedEvil, the yellow fuzzy bit in the middle is when the transmitter was off
[18:26] sbasuita (n=sbasuita@unaffiliated/drebellion) joined #highaltitude.
[18:26] <natrium42> jcoxon, wednesday
[18:26] <jcoxon> natrium42, cool
[18:31] <edmoore> natrium42: direct to italy from canada?
[18:31] <natrium42> through US
[18:32] <edmoore> cool
[18:32] <edmoore> thought we might be able to accost you in a london transfer
[18:33] <natrium42> unfortunately not :S
[18:36] <Fighter1405> SpeedEvil?
[18:41] <SpeedEvil> afk\
[18:51] <SpeedEvil> back a bit
[18:52] <SpeedEvil> as to what it should sound like - look at websdr.ewi.utwente.nl:8901
[18:53] <SpeedEvil> the second band - near the middle is something sounding like rtty or something not dissimilar.
[18:53] <SpeedEvil> afk again - have to take bins out
[18:56] <Fighter1405> ok
[19:01] RocketBoy (n=Steve@217.47.75.8) joined #highaltitude.
[19:08] <edmoore> hi RocketBoy
[19:13] <jcoxon> bbl
[19:13] jcoxon (n=jcoxon@host86-146-165-194.range86-146.btcentralplus.com) left irc: "Leaving"
[19:34] rjharrison (n=rharriso@80.176.172.227) joined #highaltitude.
[19:53] <rjharrison> .
[19:53] <natrium42> ,
[20:19] <edmoore> `
[20:20] Hiena (n=Hiena@81.93.195.181.datatrans.hu) joined #highaltitude.
[20:20] <RocketBoy> hey edmore
[20:24] <edmoore> got the balloon, thank you
[20:27] <RocketBoy> excellent - I'll let you know when the next lot come in
[20:29] <edmoore> ta
[20:34] <natrium42> o_O
[20:38] <Fighter1405> Any of you cambridge lot do computer science?
[20:44] <edmoore> no
[20:44] <edmoore> but ask
[20:45] <Fighter1405> I was only interested in what it was like, considering applying
[20:46] <edmoore> ah right
[20:46] <edmoore> well fergusnoble did 50% compsci 50% natsci in his first year, but went down the natsci route
[20:46] <edmoore> i think you'd do 50% natsci or engineering or something in your first year too. not sure.
[20:46] <Fighter1405> Ah, I could ask him if I see him around then. He should have a good idea. Thanks
[20:48] <natrium42> what's better, cambridge or oxford?
[20:48] <Fighter1405> From what I've read, cambridge is for compsci
[20:49] <Fighter1405> Yeah, Times says cambridge is on top
[20:49] <natrium42> cool
[20:49] <Fighter1405> I'm a little concerned not doing double maths damaged my chances, but hopefully taking an AS in further maths next year could make up for that to some extent
[20:54] Bertrix (n=Bertrix@94-225-132-78.access.telenet.be) left irc: Remote closed the connection
[21:04] <edmoore> Fighter1405: that should be OK
[21:04] <edmoore> as long as you show willing :)
[21:04] Hiena (n=Hiena@81.93.195.181.datatrans.hu) left irc: "-=Mi ez a szag? Hippit égettéll?=-"
[21:04] <edmoore> would you take a gap year?
[21:24] borism (n=boris@195-50-197-144-dsl.krw.estpak.ee) joined #highaltitude.
[21:30] borism_ (n=boris@195-50-200-18-dsl.krw.estpak.ee) left irc: Read error: 145 (Connection timed out)
[22:04] sbasuita (n=sbasuita@unaffiliated/drebellion) left irc: "Quit"
[22:06] sbasuita (n=sbasuita@unaffiliated/drebellion) joined #highaltitude.
[22:31] SpeedEvil (n=user@tor/regular/SpeedEvil) left irc: Read error: 110 (Connection timed out)
[22:35] <Fighter1405> edmoore sorry, wemt out. Unlikely unless there is anything in particular I should be doing?
[22:35] <Fighter1405> *went
[22:35] <edmoore> probably not, just wondering
[22:36] <edmoore> but maths is the key - if you want to read around it before interview, so much the better
[22:36] <Fighter1405> Yeah, a little more difficult with computer science than other subjects I guess. From what I'm told the interview tends to be logic puzzles
[22:37] <edmoore> can I suggest the stuff that you don't get to in a-level where it starts to get interesting, like convolution and the laplace and fourier transforms
[22:37] <edmoore> or maybe lamda calculus and functional programming for a more compsci slant
[22:37] <Fighter1405> I see, I won't pretend to know what any of those are but I'll note them down. Thanks :)
[22:37] <edmoore> do
[22:37] <Fighter1405> Would you reccomend doing the decision mathmatics module?
[22:38] <edmoore> I guess you should as a compsci
[22:38] <edmoore> was a bit of a joke though
[22:38] <Fighter1405> Haha, sounds good :p I'd rather do it than another stats anyway
[22:38] <edmoore> you probably want to start reading the bible too
[22:38] <edmoore> hrm, they might prefer stats
[22:38] <Fighter1405> the bible? :o
[22:38] <edmoore> they *love* maths
[22:38] <Fighter1405> I did S1, and I presume I will do S2
[22:38] <edmoore> the bible = The Art of Programming by Donald Knuth
[22:38] <Fighter1405> Will they want more than that?
[22:38] <Fighter1405> Ah I see
[22:39] <Fighter1405> I'll write that down too, thanks :)
[22:39] <edmoore> S2 should be fine
[22:39] <Fighter1405> How complex is it?
[22:39] <edmoore> it basically covers all of computer science
[22:39] <Fighter1405> Ah, worth it then
[22:39] <edmoore> so it goes from the basics to yes, very complicated
[22:39] <edmoore> it's immensely rigorous
[22:40] <Fighter1405> I'm trying to work my way through "The Ansi C programming language" at the moment to give some kind of basic understanding
[22:40] <Fighter1405> Is that worth doing?
[22:40] <edmoore> the whole course is a bit language agnostic, as far as I understand
[22:40] <edmoore> they're not into any specific language, more like algorithms and data structures (with TAOP rocks at)
[22:40] <edmoore> lamda calculus
[22:41] <edmoore> then lots of maths
[22:41] <edmoore> set theory and so on
[22:41] <Fighter1405> Yeah, I heard cambridge was particularly mathematical for it ^^
[22:41] <edmoore> http://www.cl.cam.ac.uk/admissions/undergraduate/year1.html
[22:42] <Fighter1405> o0 the 'bible' is long and expensive, do I need to read all the volumes?
[22:42] <Fighter1405> ooh, never seen that page before. Thanks
[22:42] <edmoore> I'd just concentrate on reading what you can and understanding it
[22:42] <edmoore> don't worry about getting through it
[22:42] <edmoore> it's more a reference
[22:42] <edmoore> you could start playing with ML now
[22:43] <Fighter1405> Ah I see
[22:43] <edmoore> I think you need to learn to love it
[22:43] <Fighter1405> Right :p
[22:44] <edmoore> this is much better
[22:44] <edmoore> http://www.cl.cam.ac.uk/teaching/0809/part1a-cst.html
[22:44] <edmoore> it's for actual students
[22:44] Mogwie (n=johan@66.186.190.58) left irc: "This computer has gone to sleep"
[22:44] borism_ (n=boris@195-50-199-95-dsl.krw.estpak.ee) joined #highaltitude.
[22:44] <edmoore> you can see notes and so on
[22:44] <Fighter1405> Thanks again
[22:45] <edmoore> don't worry if it looks a bit daunting
[22:45] <edmoore> it's sort of designed to be
[22:45] <edmoore> but you get used to it
[22:45] <Fighter1405> I'm sure :p
[22:45] <Fighter1405> And it's correct you don't need any IT or computing qualifications before yes?
[22:46] <edmoore> maths and physics are all they care about
[22:46] <Fighter1405> Good, I do both and I'll do further maths next year
[22:47] <Fighter1405> Work experience worth it?
[22:47] <edmoore> might be
[22:48] borism (n=boris@195-50-197-144-dsl.krw.estpak.ee) left irc: Read error: 145 (Connection timed out)
[22:48] <edmoore> i think if you've done something like contribute to an open source project, they'd love that
[22:48] <edmoore> especially if it's something with some nice theory, like File Systems or something
[22:48] <Fighter1405> Ah, I'm not sure I'd really have the knowledge to do that yet =/
[22:49] <edmoore> no no, indeed. that's the deep end
[22:49] <Fighter1405> I was rather hoping they wouldn't want too much actual programming experience
[22:50] <edmoore> but you catch my drift - a good knowledge and interest in the academic discipline is good stuff for interviews. Knowing a couple of different sort algorithms and their complexity, for example, helps
[22:50] <edmoore> they won't
[22:50] <edmoore> don't worry
[22:50] <edmoore> that's why they start you with ML in the first year
[22:50] <edmoore> as almost no one has used it
[22:50] <Fighter1405> ok, good :)
[22:50] <Fighter1405> The most I've really done is quite a bit with PHP and then trying to work through this C book
[22:51] <edmoore> i think trying to code something works better than reading, at least initially
[22:52] <edmoore> then once you get stuck into a problem, you can think more about nice ways of doing it, or using more niche features of the language
[22:52] <Fighter1405> Any suggestions for projects that might be worthwhile things to work on as an introduction?
[22:52] <edmoore> stackoverflow.com is a good place, btw
[22:52] <edmoore> something ballooney is an obvious starting point :)
[22:53] <Fighter1405> Yup, maybe I should be doing the flight computer with an AVR and C
[22:53] <edmoore> stackoverflow is good at doing things 'properly' - good algorithms, design patterns, approaches to things in general.
[22:54] <Fighter1405> got it
[22:54] <edmoore> You should also get an intuitive feel for the difference between imperative programming (eg C/Java) and functional programming, eg Haskell/ML
[22:54] <edmoore> I think that would impress an interviewer. And it also helps you get your head around programming a lot more
[22:55] <Fighter1405> Right, so looking at ML would certainly be worthwhile
[22:55] <edmoore> Haskell seems cool, and increasingly popular
[22:55] <Fighter1405> What do you study if you don't mind me asking?
[22:55] <edmoore> yeah, Haskell/ML. ML is less popular, I might be inclined to try Haskell.
[22:55] <edmoore> Engineering
[22:55] <Fighter1405> Ah nice
[22:55] <Fighter1405> ML has the advantage you've already seen it when you get to the first year though :p
[22:56] <edmoore> The idea of the course for comsci is that you learn enough about programming languages in general that you should be able to pick up a new language in a day or two. The actual language shouldn't matter, it's just the concepts that underpin it
[22:56] <Fighter1405> Got it
[22:57] <edmoore> So when you start ML, having done Haskell, it will seem familiar, you'll know how to program and solve basic probs in a functional way
[22:57] <edmoore> plus Haskell has great tutorials, a supremely good irc channel #haskell and a compiler and good cross-platform support
[22:57] <Fighter1405> I assume functional programming is all through using functions?
[22:57] <edmoore> correct
[22:58] <Fighter1405> Which feature in C and so on, but aren't so important?
[22:58] <edmoore> you give a function some parameter and it returns some parameter, and does nothing else
[22:58] <Fighter1405> Ah I see
[22:58] <edmoore> you can't fiddle with external stuff within a function, like turn on a light or change the date, you just take eg a number and do something with it and return eg a number
[22:59] <Fighter1405> Yeah, so it is all local
[22:59] <edmoore> pretty much yes
[22:59] <edmoore> so it's exciting people researching parallel programming
[22:59] <edmoore> on the next generation of 4/8/16 core devices
[23:00] <edmoore> as you "know" that the function won't affect some bit of cache that another function needs, or whatever, it's all entirely limited in its scope and sandboxed off. you can give one core that function and its input and it will need nothing else, nor fiddle with anything else, to calculate and return the result
[23:01] <Fighter1405> Ah I see
[23:01] <edmoore> it's really just a different way of going about similar things, and learning one will help you with the other.
[23:02] <edmoore> anyway, your brain is hurting probs
[23:02] <Fighter1405> Well thanks for all that :) You've given me a lot to get on with there
[23:02] <Fighter1405> Haha, only slightly ;)
[23:03] <edmoore> but in summary - 'computer science stuff' - algorithms (hash search, djystra's algorithm etc), maybe a functional language like haskell, and do some balloon stuff in C. And you'll be laughing
[23:04] <Fighter1405> Great
[23:04] <Fighter1405> And of course the TSA to do :s
[23:04] <edmoore> wouldn't worry too much about that
[23:05] <edmoore> though i never did that, it was after my time
[23:05] <edmoore> infact
[23:05] <edmoore> here you go
[23:05] <edmoore> project Euler
[23:05] <edmoore> if you can do them (and Haskell is a *great* language to do them in) then you will totally, completely, utterly crush the TSA
[23:05] <edmoore> and a lot of your degree
[23:06] <Fighter1405> Great, I'll look at that too then :D
[23:08] <edmoore> they're are a seriously good thing to do. some of them get *very* hard
[23:08] <Fighter1405> Right, may need to learn some Haskell first
[23:09] <Fighter1405> Or are the first ones easy enough to use as an introduction?
[23:09] Action: sbasuita reads up and contemplates compsci
[23:09] <edmoore> there are quite a few 'project euler with haskell' guids
[23:10] <edmoore> there's a good haskell wikibook
[23:10] <edmoore> do some google and ask on #haskell
[23:11] <Fighter1405> great, I'll do that
[23:11] <edmoore> what OS do you use?
[23:11] <Fighter1405> Any tutorials you reccomend in particular?
[23:11] <edmoore> i used the wikibook but there might be better. I'm not really an expert though
[23:11] <edmoore> i did a few of them in matlab
[23:11] <Fighter1405> Desktop on xp, laptop on vista and my 'server' (read: tacky old PC I got for free) on linux
[23:11] <edmoore> as an engineer, that's my happy language
[23:12] <edmoore> ok cool. in general, familarity with unix is a good thing. sounds like you've got that so no probs
[23:16] <Fighter1405> wow, functional languages do look quite different
[23:17] <edmoore> yeah - it's a fundamentally different way of going at the problem of making computers do things
[23:18] <edmoore> but understanding those differences is really good for your brain
[23:21] <Fighter1405> Got it
[23:24] <edmoore> my parting advice before I got back to typing this silly report is to always try and see and understand why something has been done the way it has. The specific syntax doesn't really matter, what were they thinking when they made the language do it that way, and why is that useful? What was so bad about the way it was done in C++ that means they do it this way in Java?
[23:24] <edmoore> And you can always ask them - both Stroustrup (C++ inventor) and Peyton-Jones (haskell inventor) are Cambridge men
[23:26] <Fighter1405> Ah neat, thanks again for all :) You've been a great help
[23:27] <edmoore> well, ask fergusnoble when he comes on - all the above is only stuff i've picked up on as an outsider
[23:27] <edmoore> but once again, they do like their maths. Find a good book on set theory
[23:28] <edmoore> it's a fascinating and fundamental part of mathematics
[23:28] <edmoore> lots of the axioms of maths (the fundamental building blocks) are defined in terms of set theory
[23:28] <Fighter1405> Great, I'll look out for him as well
[23:28] <edmoore> like 'what is zero' and 'why does one plus one equal 2' and so on.
[23:29] <Fighter1405> I think I'll need to find a new library for all these books ^^
[23:30] <edmoore> the art of programming is one of those mega presents
[23:30] <edmoore> but a great one
[23:31] <Fighter1405> ok :)
[23:31] <edmoore> Donald Knuth is a bit of a legend
[23:31] <edmoore> he wrote Tex (oh yeah, learn Latex for reports and stuff. it's a joy)
[23:32] <natrium42> what sucks is that G8 is in italy and coincides with our trip :S
[23:32] <Fighter1405> Never heard of it, but ok ^^
[23:33] <edmoore> it's a typstting system used in academia a whole lot
[23:33] <edmoore> very good at equations
[23:34] <edmoore> don't worry about it till you get here. your list is long enough and exciting enough already
[23:35] <Fighter1405> ok :p
[23:41] Mogwie (n=johan@cpe-74-75-100-121.maine.res.rr.com) joined #highaltitude.
[23:47] Mogwie (n=johan@cpe-74-75-100-121.maine.res.rr.com) left irc: "This computer has gone to sleep"
[23:49] SpeedEvil (n=user@tor/regular/SpeedEvil) joined #highaltitude.
[23:58] sbasuita (n=sbasuita@unaffiliated/drebellion) left irc: "Leaving"
[00:00] --- Sat Jun 27 2009