highaltitude.log.20060604

[00:00] <phatmonkey> anywho, night
[00:00] phatmonkey (n=phatmonk@65.98.2.81.in-addr.arpa) left irc: "Ex-Chat"
[00:01] <jcoxon> hmmm ho
[00:01] <jcoxon> perhaps i should think about some insurance
[00:02] <jcoxon> right i better get to bed
[00:02] <jcoxon> got to start revision again :(
[00:02] <Tiger^> yeah, "morning, i need a liability-for-damage insurance"
[00:03] <Tiger^> "sure, what's the make of the car?"
[00:03] <jcoxon> hehe
[00:03] <Tiger^> "well... actually, it's a 1500g weather balloon"
[00:03] <Tiger^> ;>
[00:03] <jcoxon> wouldn't worry about the balloon!
[00:03] <Tiger^> yeah
[00:03] <jcoxon> night Tiger^
[00:03] <jcoxon> chat soon
[00:03] <Tiger^> night :)
[00:04] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) left irc: "Ex-Chat"
[00:13] macfreak4 (n=macfreak@24-107-201-22.dhcp.stls.mo.charter.com) joined #highaltitude.
[00:36] macfreak4 (n=macfreak@24-107-201-22.dhcp.stls.mo.charter.com) left irc: Remote closed the connection
[05:10] macfreak4 (n=macfreak@24-107-201-22.dhcp.stls.mo.charter.com) joined #highaltitude.
[07:18] macfreak4 (n=macfreak@24-107-201-22.dhcp.stls.mo.charter.com) left irc: Remote closed the connection
[08:09] icez (n=icez@ip68-3-56-121.ph.ph.cox.net) left irc: Remote closed the connection
[08:25] defy (n=defy@60-234-234-98.bitstream.orcon.net.nz) joined #highaltitude.
[08:42] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) joined #highaltitude.
[08:50] <defy> hey
[08:50] <defy> hows it going
[08:51] <jcoxon> hey defy
[08:51] <jcoxon> its going okay
[08:51] <jcoxon> you?
[08:52] <defy> yea same old, relaxing after a sunday full of work
[08:55] <jcoxon> hehe sunday has only just begun :-D !
[08:56] Action: jcoxon only has one exam left
[08:56] <defy> lol
[08:56] <defy> sweet
[08:57] <jcoxon> need to start working on building a payload case
[08:58] <defy> cool
[08:58] <defy> did you end up getting any wireless modules?
[08:58] <jcoxon> sadly the guy in america who was going to help can't now
[08:58] <jcoxon> i've got the 868mhz dev kit on its way
[08:58] <jcoxon> there was a little trouble about method of payment
[08:58] <jcoxon> but thats sorted now
[08:59] <jcoxon> i reckon it'll arrive on weds
[08:59] <defy> awesome, those are legal where you are?
[08:59] <jcoxon> (perfect as i'd have finished my exam
[08:59] <jcoxon> )
[08:59] <jcoxon> thats the thing
[08:59] <jcoxon> i'm not to sure
[08:59] <defy> hehe
[08:59] <defy> the aerocomms?
[08:59] <jcoxon> yeah
[08:59] <defy> sweet
[08:59] <jcoxon> 868mhz are legal
[08:59] <jcoxon> but in payloads i'm not sure
[08:59] <jcoxon> i think they are considering they are ISM
[09:00] <jcoxon> they are as legal as wifi would be
[09:00] <defy> thats cool, i was hoping i could use those here but i dont think i can, you should be able to get pretty good range with them
[09:00] <jcoxon> 868 are only 15km :(
[09:00] <jcoxon> not the 900mhz which are 32
[09:00] <defy> ah true, i thought they were the same wattage?
[09:01] <jcoxon> yeah
[09:01] <jcoxon> i reckon they'll go further
[09:01] <defy> get some nice antennas
[09:01] <jcoxon> just cause there won't be anything in between
[09:02] <jcoxon> need to learn about all this antenna stuff
[09:02] <defy> I'll be interested to know how you get on with the aerocomms, i might still pickup a set while I'm in the US in july
[09:02] <jcoxon> no probs
[09:03] <jcoxon> i'll be documenting everything like usual
[09:03] <defy> cool
[09:03] <defy> i'm so horrible with documenting stuff, lol
[09:04] <jcoxon> well i sort of do it afterwards
[09:04] <jcoxon> best to make sure it works first
[09:05] <defy> hehe
[09:11] <jcoxon> trying to work out what to do about if i need insurance for peg III
[09:12] <defy> what do you mean?
[09:13] malgar (n=malgar@adsl-ull-247-203.47-151.net24.it) joined #highaltitude.
[09:13] <jcoxon> well what happens if it hits something/ somebodt
[09:13] <jcoxon> somebody*
[09:13] <defy> ah actual insurance, yea that would suck
[09:26] <jcoxon> hmmm better talk to some insurance people
[09:26] <jcoxon> not a fan of getting in trouble
[09:27] <defy> yea, specially if you take down an airliner
[09:27] <jcoxon> i'm actually not worried about aircraft
[09:27] <jcoxon> it wouldn't be for that
[09:27] <defy> i think thats probably the worst thing that could come from a project like this, but the odds are so low, and the precations taken are so high
[09:28] <jcoxon> remember that they've launched so many balloons a day for weather stuff since about 1940
[09:28] <defy> yeah
[09:28] <jcoxon> and there has never been a recorded collision
[09:28] <jcoxon> the sky is a big volume
[09:28] <jcoxon> and the payload is damn small
[09:28] <jcoxon> but
[09:28] <jcoxon> its gonna hit the ground eventually
[09:28] <jcoxon> and the UK is pretty dense
[09:28] <defy> definitely, it wouldnt happen, but i just mean its the worst thats physically possible..
[09:29] <jcoxon> yeah
[09:29] <defy> but yea, with the uav i have actually been a bit worried about hitting something important
[09:29] <jcoxon> this all started cause i've been discussing with phatmonkey his uav
[09:29] <jcoxon> and if its even allowed here...
[09:29] <defy> a foam box is one thing, something aerodynamic and heavy is another
[09:30] <jcoxon> yeah i know
[09:30] <jcoxon> i'd be less worried about NZ though
[09:30] <defy> but nz has a LOT of very wide open mountain side
[09:30] <jcoxon> yeah
[09:30] <jcoxon> but few plans
[09:30] <defy> and i plan on doing lots of lower level drops
[09:30] <jcoxon> considering how many airports there are around london
[09:30] <defy> oh yea definitely
[09:33] <defy> has phatmonkey built prevous uavs? or working on one?
[09:33] <jcoxon> hes planning one
[09:33] <jcoxon> though they aren't really true UAVs
[09:33] <jcoxon> just autonomous gliders
[09:33] <defy> yea, mine will be too, i wouldn't dare try make the thing take off or land on its own
[09:34] <jcoxon> whats the need
[09:34] <jcoxon> and thats the thing does it count as a UAV (if it does the law is against it)
[09:34] <jcoxon> or is it a controlled descent from a balloon
[09:35] <defy> so actual motored uav's are not legal there?
[09:35] <jcoxon> within limits
[09:35] <jcoxon> so if you adapted a rc plane it couldn't go out of sight
[09:35] <jcoxon> like normal rc planes
[09:36] <defy> interesting, i should look into those laws here, I bet they don't even exist
[09:36] <jcoxon> prob not
[09:36] <jcoxon> have you spoken to the guy in NZ who has actually got a glider working?
[09:36] <defy> the gpsboomerang people?
[09:36] <jcoxon> yeah
[09:37] <defy> once briefly by email after he was on the news
[09:37] <jcoxon> oh right
[09:37] <defy> pretty cool little plane he's made, he said he's done about 200 drops and only lost a couple of planes, and spent about $70k doing it
[09:37] <jcoxon> last year he was on this channel
[09:37] <jcoxon> yeah
[09:37] <jcoxon> he hasn't actually pushed that high yet
[09:38] <jcoxon> but i looks good
[09:38] <jcoxon> and if he can do it so can you!
[09:38] <defy> trying to make a business out of it, I'm not too sure how successful its been though
[09:38] <jcoxon> legal speaking that is
[09:38] <defy> hehe yea exactly
[09:38] <defy> he's in a better place to do it than me though, christchruch is quite a bit flatter
[09:39] <defy> I was playing with the idea for a bit, about making something that i would make sure dropped in the ocean, and made its way back to a beach on its own, but i think the distances involved would require too much power
[09:42] <jcoxon> hehe
[09:42] <jcoxon> i'd stick to land!
[09:42] <defy> hehe
[09:43] <defy> well it would solve so many other problems, landing...directional nav would only need to be 2d...sharks would be a bitch though
[09:43] <jcoxon> hehe
[09:51] <jcoxon> you know the aerocomms
[09:51] <jcoxon> do they reestablish contact when back in range?
[09:51] <defy> I'm not too sure, i imagine they'll work the same way these maxstreams work, so it will depend on how you're linking them, but yea i think the actual serial connection is simply open if there is signal
[09:52] <defy> i have to restart pppd if i lose signal, but that happens very quickly...the serial its self either works if theres signal, or doesn't if there isn't signal
[09:52] <jcoxon> so like good old dodgey dialup
[09:53] <defy> hehe yea, without the dialing
[09:53] <jcoxon> cool
[09:53] <jcoxon> well i've got a week and a half to experiment
[09:55] <defy> sweet
[09:55] <defy> are they 3.3v ttl or rs232?
[09:57] <jcoxon> ttl
[09:59] <defy> sweet nice and easy then
[10:00] <jcoxon> brb
[10:00] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) left irc: "Ex-Chat"
[10:05] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) joined #highaltitude.
[10:13] <jcoxon> grrr
[10:14] <defy> ?
[10:14] <jcoxon> my gumstix filesystem just corrupted
[10:14] <jcoxon> add_node: malloc failed
[10:14] <jcoxon> add_node failed!
[10:14] <jcoxon> load: Failed to scan JFFSv2 file structure
[10:14] <jcoxon> ### JFFS2 LOAD ERROR<0> for boot/uImage!
[10:15] <defy> hah did you see my most recent mailing list post? it was about the same issue
[10:15] <jcoxon> nope
[10:15] <defy> i never got it back
[10:16] <defy> i dont think sourceforge has processed it yet
[10:16] <defy> but i was getting the same thing
[10:16] <defy> but only when i shut the gumstix down uncleanly, while writing to the disk a lot
[10:16] <jcoxon> thats what i was doing
[10:16] <defy> yea :P
[10:16] <jcoxon> i was cat to a file i think from the gps
[10:16] <defy> if you type 'boot' at the prompt
[10:16] <defy> you can still boot the gumstix
[10:17] <defy> but i couldnt figur eout how to fix the booting problem, other than reflashing
[10:17] <jcoxon> ooo
[10:17] <defy> so now i write all my logs to compact flash or mmc
[10:17] <defy> instead of the gumstix
[10:17] <defy> which is a pain, cause it knocks about an hour off the battery life
[10:17] <defy> but its better than dead file systems
[10:17] <jcoxon> i'll reflash
[10:17] <jcoxon> might update the buildroot
[10:18] <defy> i never got a reply to my email, it will probably come through next week, lol
[10:18] <defy> damn sourceforge
[10:19] <jcoxon> hehe
[10:19] <jcoxon> hmmm i don't have mmc
[10:19] <jcoxon> are you using gpsd with your gpstix?
[10:19] <defy> yup
[10:20] <jcoxon> and then how do you log?
[10:21] <defy> with a sh script and nc
[10:22] <jcoxon> oh right
[10:22] <defy> http://defy.net/gpsd_while.sh.txt
[10:22] <defy> then just ./gpsd_while.sh | nc localhost 2947 >> somelogfile.txt &
[10:23] <defy> so i get an O gpsd line every second, and the nmea
[10:23] <jcoxon> interesting
[10:23] <jcoxon> you deal with raw nmea then
[10:24] <defy> i can do yeah
[10:24] <jcoxon> hmmm
[10:24] <defy> its weird
[10:25] <jcoxon> i have a little program which gets P, A and D off gpsd
[10:25] <jcoxon> and that was fine for normal gps
[10:25] <defy> gpsd is weird in the way it returns responses, i guess it only returns a the last value it recieves
[10:25] <jcoxon> but it seems to have issues with this module
[10:25] <defy> and this gps only gives an altitude once every second, so quite often i get empty altitude readings, unless i read the nmea stream
[10:25] <jcoxon> i think the refresh rate is to quick
[10:25] <jcoxon> excactly
[10:25] <jcoxon> just what i was going to say
[10:25] <defy> hehe
[10:25] <defy> i took me a while to figure out why the altitude reading was off so often
[10:25] <jcoxon> so if i miss time the A command i get a ?
[10:26] <defy> yeah
[10:26] <jcoxon> so i thought i'd grab all the stream
[10:26] <jcoxon> but it takes up to much space
[10:26] <defy> one in every 5 of my O lines would have the actual altitude
[10:26] <jcoxon> i only have about 11mg
[10:26] <defy> I was thinking of writing a daemon
[10:26] <defy> that watched the nmea stream
[10:26] <defy> and just picked out the info and logged in
[10:26] <jcoxon> i'd be very interested in that
[10:26] <defy> but freakin microperl is so limited, i cant pipe programs into a file handler for some reason
[10:27] <jcoxon> oh
[10:27] <defy> so that leaves me with C, which I haven't written anything in in years
[10:27] <jcoxon> i'd do C++
[10:27] <jcoxon> well i might try something on the weekend
[10:27] <defy> I'm just so lazy, i like small programs like that to be less than 15 lines, which it could easily be in perl
[10:27] <jcoxon> basically we need a NMEA parser
[10:27] <defy> yeah exactly
[10:28] <jcoxon> that doesn't log A=? but A=xx
[10:28] <jcoxon> hmmm shouldn't be difficult
[10:28] <jcoxon> i sometimes think gpsd is over complicated
[10:29] <defy> hehe
[10:30] <defy> could always patch gpsd as well, to use the last valid value if a ? on A is received, but a parser makes more sense
[10:30] <defy> i'm sure it could be done in sh
[10:30] <defy> but i dont know it well enough
[10:37] <defy> do you compile on a host machine or on the gumstix?
[10:59] <jcoxon> on my ppc
[11:00] <jcoxon> right i better be off
[11:00] <jcoxon> have to start revision for my final exam
[11:00] <jcoxon> then i'll be free!
[11:01] <jcoxon> cya defy
[11:01] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) left irc: "Ex-Chat"
[13:25] ehj20 (i=ed@ehjones.plus.com) joined #highaltitude.
[14:48] macfreak4 (n=macfreak@24-107-201-22.dhcp.stls.mo.charter.com) joined #highaltitude.
[15:09] malgar (n=malgar@adsl-ull-247-203.47-151.net24.it) left irc: "*** E' solo l'urto con un iceberg, che vuoi che sia, questa è una nave inaffondabile. *** 75$/barile"
[15:15] malgar (n=malgar@adsl-ull-247-203.47-151.net24.it) joined #highaltitude.
[15:19] macfreak4 (n=macfreak@24-107-201-22.dhcp.stls.mo.charter.com) left irc: Remote closed the connection
[16:15] jcoxon (i=keefejoh@seraph.techwareit.com) joined #highaltitude.
[16:16] <jcoxon> hey all
[16:22] <ehj20> hi
[16:22] <ehj20> Are you still on for a May week launch?
[16:26] <jcoxon> yup
[16:27] <jcoxon> the launch window should open on the friday before may week
[16:27] <jcoxon> if all is ready we launch when the weather is good
[16:29] <ehj20> Excellent. Any predictions on what the wind direction will be?
[16:32] <jcoxon> difficult to predict
[16:32] <jcoxon> looking at some of the models it seems that a high pressure might be approaching
[16:33] <jcoxon> if we can catch the northern part of that as high pressure systems always turn anti-clockwise we'll get a perfect easterly wind
[16:33] <jcoxon> but the jet stream is a different matter
[16:35] <jcoxon> slightly worried about if the nova 1 payload will be ready
[16:39] <ehj20> http://www.bbc.co.uk/weather/features/understanding/jetstreams_uk.shtml
[16:40] <ehj20> seems to suggest the jetstream will be westerly/northwesterly perhaps? I don't know much about these things
[16:40] <jcoxon> yeah
[16:40] <jcoxon> it usually is
[16:41] <jcoxon> http://www.wunderground.com/global/Region/i_UK/2xJetStream.html
[16:43] <jcoxon> ignore what i said about anticlockwise
[16:44] <jcoxon> its the other way round
[16:44] <jcoxon> so we want to get the southern part of a high pressure zone
[16:44] <jcoxon> actually the middle of one would be best :-D no wind
[16:55] <ehj20> What weight balloon will you be using? 200g as in Pegasus I?
[16:56] <jcoxon> :-)
[16:56] <jcoxon> yeah
[16:56] <jcoxon> i have a 500g but i've been persuaded to use a 200g
[16:57] <jcoxon> really just want a sucessful flight - will be testing a new system
[16:57] <ehj20> hehe, sounds good to me!
[16:57] <jcoxon> can't really afford to lose it
[16:57] <jcoxon> ehj20: do sign up at www.ukhas.org.uk
[16:59] <ehj20> Thanks, I will. Yor
[16:59] <ehj20> sorry - Your project has inspired me
[17:00] <jcoxon> cool
[17:00] <jcoxon> so whats the plan?!
[17:00] <ehj20> I see the ascent of P1 was pretty much constant, I perhaps thought it might accelerate as it got higher and the balloon increased in volume.
[17:00] <ehj20> but i guess the thinner air at higher altitudes offsets that.
[17:01] <jcoxon> yeah, the force remains the same and so does gravity
[17:01] <jcoxon> and the air density changes as the balloon expands
[17:03] <ehj20> I guess it's obvious when I think about it. A balloon under water offers more bouyancy as it ascends - the difference being the water remains at the same density
[17:04] <ehj20> Hmmm, a plan. Perhaps I should have one of those ;-)
[17:04] <ehj20> First I'll see if I can interface a gps, a phone and a gumstix in a similar way that you have.
[17:04] <ehj20> then go from there
[17:05] <jcoxon> :-D
[17:05] <jcoxon> where would you be launching from out of interest?
[17:05] <ehj20> north yorkshire
[17:05] <ehj20> Unfortunately the dales have significantly worse gsm coverage than cambridgeshire...
[17:06] <jcoxon> yeah
[17:06] <jcoxon> but a northerly jet stream would give a fair distance before the sea
[17:09] <ehj20> good point, and gsm coverage would be much better further south.
[17:10] <jcoxon> yeah
[17:10] <jcoxon> though i haven't said on my website I'm going to also be using radio modems on peg III
[17:11] <ehj20> i read form a similar project in the US (I forget the name) that the fragmentsof the burst balloon interfered with the parachute, resulting in a faster than optimal descent....
[17:11] <jcoxon> should give me a 15km (perhaps more) live feed
[17:11] <jcoxon> yeah
[17:11] <jcoxon> its a problem
[17:11] <jcoxon> i'm going to be doing some drop tests next week once my exams are over to see if there is a problem
[17:11] <ehj20> a cutoff would be good, but would limit the maximum altitude obviously.
[17:12] <ehj20> radio modem sounds cool
[17:14] <jcoxon> well we've been thinking of allowing hte balloon to burst and then cutting down
[17:14] <jcoxon> but not sure how happy people would be with the remains of hte balloon falling out of the sky
[17:19] <ehj20> Just fragments of the balloon probably wouldn't be a problem. I would imagine the cutdown mechanism would have to stay attached to the payload.
[17:20] <jcoxon> but when it bursts it leaves the nozzle bit of the balloon
[17:20] <jcoxon> which is made of thicker totex
[17:20] <jcoxon> the cutdown device could easily be below the parachute
[17:21] <ehj20> ah, fair enough. But any cutdown mechanism would have the same problem, although a secondary parachute for the balloon remains could be used.
[17:21] <jcoxon> yeah
[17:21] <ehj20> s/balloon remains/remians of the balloon/
[17:22] <jcoxon> will have to see
[17:24] <ehj20> where will you do your drop tests from? The top of the UL might be good :-]
[17:24] <jcoxon> hehe
[17:24] <jcoxon> not sure they'll let me
[17:24] <jcoxon> not to sure
[17:25] <ehj20> hehe, I can't see it myself...
[17:26] <jcoxon> i guess out from where i live
[17:26] <jcoxon> though i think i might look a little strange
[17:28] <ehj20> you could attach something suitably alcoholic looking as ballast (like a bottle of champagne) and i'm sure no one will bat an eyelid.
[17:28] <jcoxon> hehe
[17:28] <jcoxon> there are a load of cranes around right now :-p
[17:33] <ehj20> a few years ago there was a crane parked in king's parade that was being used to lift pre-fabricated rooms to make an extra floor on a building in kings (or perhaps in Catz, not too sure). That would have been perfect, if a little bit over-kill...
[17:33] <ehj20> http://www.kempley.net/crane/
[17:36] icez (n=icez@ip68-3-56-121.ph.ph.cox.net) joined #highaltitude.
[17:37] <ehj20> $46.66 shipping from gumstix :-(
[17:38] <jcoxon> yeah
[17:39] <jcoxon> there are other options
[17:39] <jcoxon> such as a slug
[17:39] <jcoxon> or Ed_Moore showed me this
[17:39] <jcoxon> one sec i'll find the link
[17:39] <jcoxon> http://www.crownhill.co.uk/product.php?prod=1456
[17:40] <jcoxon> looks nice
[17:40] <jcoxon> right i've got to go
[17:40] <jcoxon> will chat soon
[17:41] <ehj20> bye!
[17:45] jcoxon (i=keefejoh@seraph.techwareit.com) left irc: "CGI:IRC (Ping timeout)"
[18:47] ehj20 (i=ed@ehjones.plus.com) left irc: "Easy as 3.14159265358979323846..."
[18:59] ehj20 (i=ed@ehjones.plus.com) joined #highaltitude.
[19:33] malgar (n=malgar@adsl-ull-247-203.47-151.net24.it) left irc: "*** E' solo l'urto con un iceberg, che vuoi che sia, questa è una nave inaffondabile. *** 75$/barile"
[19:50] malgar (n=malgar@adsl-ull-247-203.47-151.net24.it) joined #highaltitude.
[21:25] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) joined #highaltitude.
[21:38] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) left #highaltitude ("Leaving").
[21:43] phatmonkey (n=phatmonk@65.98.2.81.in-addr.arpa) joined #highaltitude.
[22:07] ehj20 (i=ed@ehjones.plus.com) left irc: "IceChat - what the cool people use"
[22:17] phatmonkey (n=phatmonk@65.98.2.81.in-addr.arpa) left irc: "Ex-Chat"
[22:46] defy (n=defy@60-234-234-98.bitstream.orcon.net.nz) left irc: Read error: 104 (Connection reset by peer)
[22:56] malgar (n=malgar@adsl-ull-247-203.47-151.net24.it) left irc: "*** E' solo l'urto con un iceberg, che vuoi che sia, questa è una nave inaffondabile. *** 75$/barile"
[23:38] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) joined #highaltitude.
[23:43] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) left irc: Client Quit
[00:00] --- Mon Jun 5 2006