highaltitude.log.20080317

[00:01] <fuzzylugnut> digikey sells some awesome UVA and B sensors.
[00:02] <fuzzylugnut> PDU-G105A-SM
[00:02] <fuzzylugnut> PDU-G106B-SM
[00:03] <fuzzylugnut> if anyone cares about measuring UV.
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[00:09] <natrium42> fuzzylugnut, cool, thanks for the pointer
[00:09] <fuzzylugnut> np
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[01:01] <Laurenceb> http://imagebin.org/14980
[01:02] <Laurenceb> ^ thats a calibration curve for my thermistor potential divider circuit
[01:02] <fuzzylugnut> nice
[01:02] <Laurenceb> its quite nice how you can make it fairly i
[01:02] <Laurenceb> linear
[01:02] <fuzzylugnut> I use the Lm20
[01:03] <Laurenceb> Lm20?
[01:03] <fuzzylugnut> http://www.national.com/ds/LM/LM20.pdf
[01:03] <Laurenceb> I was using an LM94022
[01:04] <Laurenceb> but it got fried, then I couldnt get any of the others to work
[01:04] <Laurenceb> ( I had 4)
[01:04] <fuzzylugnut> *nod*
[01:04] <Laurenceb> havent a clue why
[01:04] <Laurenceb> never had a problem like that before, they were drawing too much current
[01:04] <fuzzylugnut> yeah, thats odd. static discharge toasting?
[01:05] <Laurenceb> nah, I was using a static free worksurface
[01:05] <fuzzylugnut> ok
[01:05] <Laurenceb> I thought the output might be oscillating, but couldnt see anything on the scope
[01:05] <fuzzylugnut> *nod*
[01:06] <Laurenceb> I found this on the web: www.yaro.at/pliki/ele/PROBLEMY.pdf
[01:07] <Laurenceb> used that to do a calibration curve for my ADC
[01:08] <fuzzylugnut> what language is that?
[01:08] <Laurenceb> polish
[01:08] <fuzzylugnut> ok
[01:09] <Laurenceb> according to that, the lab temperature is about 19 degrees C
[01:09] <Laurenceb> which sounds about right, but I need to reasure the 200K resistor as well as possible
[01:10] <Laurenceb> just put 200K into that equation
[01:10] <fuzzylugnut> I have yet to put together the sensor board yet. I've been busy with writing up my thesis.
[01:10] <Laurenceb> but the high quality thermistors seem to be quite reliable
[01:11] <Laurenceb> hehe
[01:11] <Laurenceb> what are you reading?
[01:11] <fuzzylugnut> what do you mean?
[01:11] <fuzzylugnut> oh
[01:11] <fuzzylugnut> nm
[01:11] <fuzzylugnut> *slow* : P
[01:12] <Laurenceb> ok studying
[01:12] <fuzzylugnut> oh
[01:12] <Laurenceb> not sure what terminology to use
[01:12] <fuzzylugnut> health physics
[01:12] <Laurenceb> interesting
[01:12] <Laurenceb> I'm physics
[01:12] <fuzzylugnut> ah, ok
[01:13] <Laurenceb> so is that basically standard physics until later in the course?
[01:13] <fuzzylugnut> kinda, until the second or third semester in undergrad
[01:13] <fuzzylugnut> then its the radiation related classes
[01:14] <Laurenceb> we have a biophysics subdepartment here, probably quite similar
[01:14] <fuzzylugnut> not really
[01:15] <Laurenceb> ok
[01:15] <fuzzylugnut> some courses are bio related
[01:15] <fuzzylugnut> but only about 2
[01:17] <Laurenceb> right
[01:18] <Laurenceb> I've ended up heavily involved with the atmospheric physics subdepartment
[01:18] <Laurenceb> but atmospheric science is a bit boring IMO
[01:18] <fuzzylugnut> is that where the aerosol detector idea spawned from?
[01:18] <Laurenceb> but it does mean I get to play around with balloons and call it work
[01:18] <Laurenceb> yes
[01:20] <fuzzylugnut> http://www.emcohighvoltage.com/ourprods.htm
[01:20] <Laurenceb> I've just been writing up my balloon project... http://wiki.ukhas.org.uk/_media/projects:mihab:report.pdf?id=projects%3Aaerosol&cache=cache
[01:20] <fuzzylugnut> an idea if you didn't want to use the ccfl
[01:20] <Laurenceb> that was a draft from a while ago....
[01:20] <fuzzylugnut> *click*
[01:21] <Laurenceb> nice
[01:21] <fuzzylugnut> I don't document or write up any of it, besides pictures on my webpage
[01:21] <Laurenceb> it needs more work..... I have to submit that so they know what I've been doing with all their money above all else :P
[01:22] <fuzzylugnut> looks good though
[01:22] <Laurenceb> thanx
[01:25] <fuzzylugnut> I prefer to be the guy in the corner turning this stuff out... occasionally appearing to do a presentation to show where all the grant money went.
[01:27] <fuzzylugnut> I really hate writing stuff out.
[01:27] <Laurenceb> me too ;P
[01:27] <fuzzylugnut> my advisor wants me to publish my thesis work, and i was like "yeah, uh huh....no."
[01:27] <fuzzylugnut> : )
[01:29] <Laurenceb> time to cook a midnight feast... bbl
[01:30] <fuzzylugnut> ok
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[01:53] <Laurenceb> yum pizza
[02:18] <fuzzylugnut> yum solder smoke.
[02:21] <Laurenceb> hehe
[02:21] <Laurenceb> someone has managed to get caramel or something in the bottom of our oven :(
[02:21] <fuzzylugnut> wheeee
[02:27] <fuzzylugnut> at lwast it will bake off eventually
[02:27] <fuzzylugnut> *at least
[03:29] <fuzzylugnut> 'night
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[08:39] <jcoxon> morning edmoore
[08:39] <edmoore> hi jcoxon
[08:39] <edmoore> s'up?
[08:41] <jcoxon> not much
[08:41] <edmoore> i deleted slack as I ballsed some stuff up
[08:42] <edmoore> will try again in a more awake way today
[08:42] <jcoxon> haha
[08:42] <jcoxon> i'm going on holiday tomorrow
[08:42] <jcoxon> so you'll need to get your questions in today!
[08:42] <edmoore> oooh
[08:42] <edmoore> where are you off to?
[08:43] <jcoxon> Istanbul
[08:43] <jcoxon> for a week
[08:44] <jcoxon> need a break
[08:44] <edmoore> awesome
[08:45] <edmoore> I need a break too. but sadly it'll be west sussex rather than istanbul
[08:45] <jcoxon> you should of come along
[08:45] <jcoxon> though its over easter so i'm not that popular now :-p
[08:46] <edmoore> lol
[08:46] <edmoore> should have*
[08:46] <edmoore> that's the only grammar I ever correct, but I can't help it :p
[08:46] <edmoore> gives me the willies
[08:46] <jcoxon> hehe
[08:47] <jcoxon> i'm multitasking
[08:47] <jcoxon> my common mistake is your and you're
[08:47] <jcoxon> i know the difference but just don't type it correctly
[08:47] <edmoore> I'm multitasking but not very well
[08:47] <edmoore> right, need to have some breakfast then finish report
[08:47] <edmoore> then get slackware going
[08:48] <edmoore> then do some code for badger
[08:48] <jcoxon> haha
[08:48] <jcoxon> i need to go shopping and find a printer to print out my E-ticket
[08:48] <jcoxon> not shopping for a printer though
[08:48] <jcoxon> can use the library for that
[08:48] <edmoore> yup
[08:48] <edmoore> where are you flying from?
[08:49] <jcoxon> stanstard
[08:49] <edmoore> coolio
[08:51] <edmoore> food time, bbl
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[12:54] <edmoore> hi jcoxon
[12:54] <edmoore> still report writing :(
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[15:07] <Laurenceb> hi all
[15:07] <Laurenceb> anyone installed truetty?
[15:11] <Laurenceb> ffs "evaluation period expired"
[15:14] <Laurenceb> god I hate radio stuff
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[18:13] <Hiena> Good evening!
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[18:54] <edmoore> hi jcoxon
[19:11] Laurenceb (n=laurence@dhcp39-005.sthughs.ox.ac.uk) joined #highaltitude.
[19:11] <Laurenceb> hi all
[19:11] <RocketBoy> hey ed - do you know if any of the cuspaceflight lot have joined EARS - one of them has submitted soem photos & I wanted to put them up in our "members" area.
[19:11] <RocketBoy> some
[19:12] <Laurenceb> Richard Branson is in college :o
[19:12] <Laurenceb> we're besieged by protesters
[19:13] <Laurenceb> crazy stuff :P
[19:15] <Laurenceb> RocketBoy: I've been working on the radio, seems theres two problems, the one with the first couple of bytes becoming corrupted, I've solved that by commenting out the sleep mode, and the timing problem, which looks like its my laptop at fault... also the fact you could get truetty working at all seems to support that conclusion
[19:15] <edmoore> RocketBoy: yep, Iain has
[19:15] <edmoore> tring to get his L1
[19:15] <RocketBoy> ta ed
[19:15] <Laurenceb> I've made very careful scope measurements, and there's < 0.2% error
[19:16] <RocketBoy> shouldn't be a problem then
[19:18] <Laurenceb> I miss the last character of each transmission, but that could be the way fldigi works
[19:18] <Laurenceb> its there on the scope view
[19:19] <RocketBoy> not too much of a problem - just add a charcater
[19:19] <Laurenceb> IMO fldigi probably needs another start condition or something
[19:20] <Laurenceb> maybe truetty would work better, fldigi needs the sound card sampling error <0.5% off
[19:21] <Laurenceb> which I find a bit odd... I think it must have some sort of filtering technique to avoid being upset by noisy stop/start transitions
[19:21] <Laurenceb> normal serial you can go to 3% or more error
[19:23] <Laurenceb> hmm apparently virgin are after privatising parts on the nhs... maybe I'll join the protest
[19:29] <Laurenceb> I wired up a benq GSM module this afternoon
[19:29] <Laurenceb> still need to try powering it up
[19:30] <RocketBoy> and there is me thinking it was about greenhouse emissions from all those nasty Virgin planes
[19:30] <Laurenceb> lol well its a good point
[19:30] <Laurenceb> privatised healthcare is very inefficient
[19:32] Action: Laurenceb is making a sim card holder
[19:32] <RocketBoy> well I'd have to take issue with you on that - my PPP treatment always seemed well run
[19:32] <Laurenceb> hmm well it is a bit different with "service" type industries I guess
[19:33] <Laurenceb> http://pinouts.ru/Memory/SmartCardIso_pinout.shtml using that as a guideline for the sim card...
[19:34] <Laurenceb> maybe I should add a gumstix and make my own smartphone :D
[19:38] <Laurenceb> - its not that i think private healthcare is badly run, just the fact that it is private prevents the free transfer of information and ideas throughout the health system
[19:40] <Laurenceb> but richard branson is still pretty cool :P
[19:42] <jcoxon> Laurenceb, oh come on, medicine is ridiculously open
[19:42] <Laurenceb> ah the moment
[19:42] <jcoxon> pretty much all private doctors work on the NHS as well
[19:42] <Laurenceb> and thats good
[19:42] <jcoxon> its not like they restrict the knowledge they use
[19:43] <Laurenceb> but capitalism is a bad way to look at healthcare
[19:43] <Laurenceb> it pretty incompatible theory
[19:44] <jcoxon> Laurenceb, hehe, its more that you either go fully private or fully NHA
[19:44] <jcoxon> the mess occurs when there is a half way house
[19:44] <Laurenceb> anyway.... *marches off to USSR*
[19:44] <jcoxon> hehe, their restrictions on information were a little tight me thinks
[19:45] <jcoxon> evning RocketBoy
[19:45] <Laurenceb> I've spent too long at oxford, its full of communists :P
[19:45] <jcoxon> evening*
[19:47] <jcoxon> Laurenceb, you planning to do a PhD next?
[19:48] <Laurenceb> maybe.... will have to see
[19:48] <Laurenceb> I might end up taking a year off
[19:49] <jcoxon> too much education
[19:49] <Laurenceb> very much so
[19:49] <jcoxon> tell me about it :-p
[19:49] <Laurenceb> can do some house construction instead
[19:50] <Laurenceb> actually our cottage might be finished in a couple of months
[19:51] <Hiena> Laurenceb, Do you want some brick? I have a few thousand. Used only once.
[19:52] <Laurenceb> lol it would be expensive to move
[19:53] <Hiena> I think so. ;)
[19:53] <Laurenceb> also we need georgian brick
[19:54] <Hiena> Well, mine was made 1982-1895. It was used in a mill.
[19:54] <Laurenceb> which you can only really get from architectural salvage places
[19:54] <Hiena> Most of them marked.
[19:55] <Hiena> Khm...1882-1895
[19:55] <Laurenceb> nice, we have a load from around 1840 with thumb prints
[19:56] <Hiena> Where will you use them?
[19:57] <Hiena> Fireplace?
[19:57] <Laurenceb> they are really small, as they used children about 10 years old
[19:57] <Hiena> Oh.
[19:57] <Laurenceb> theres an extension, this is the other layer
[19:59] <Hiena> I want to use few hundred as a floor tile in the cellar and the shop extension. But still has too many.
[19:59] <Laurenceb> the insulation is a pain, the wall has to be 60mm thicker than the origional plan to meet building regulations :(
[19:59] <Laurenceb> that would look nice :P
[20:01] Action: Laurenceb contemplates NGW100 phone.....
[20:02] <Laurenceb> it would be a bit big :P
[20:03] <Laurenceb> but it could have a huge touchscreen lcd and a giant lipo in between the board and screen
[20:04] <Laurenceb> of course the ngw100 schematics are on the datasheet, so you could design a much smaller, better packed board for it
[20:05] <Hiena> And a Near Space Certification logo on it. ;)
[20:06] <Hiena> "We will hear you, where nobody will hear your voice..."
[20:08] <Laurenceb> actually its supringly easy, I've seen ngw100 mods with ac97 audio, and lcds
[20:09] <Laurenceb> just need a gsm module on a serial port, and a bit of audio interfacing and your away
[20:09] <Hiena> Anybody has a C code for sound card based UART? I'm too lazy to code one.
[20:09] <Laurenceb> what do you mean?
[20:10] <Laurenceb> like afsk?
[20:10] <Hiena> Using the audio in as serial rx line.
[20:10] <Laurenceb> oh ok
[20:10] <Laurenceb> interesting idea
[20:11] <Laurenceb> nope, but I have a bit of code to grad adc readings from the audio adc
[20:11] <Laurenceb> grab*
[20:11] <Hiena> Yeah, Itried several way, i'm just simply, too lazy to cede the right one.
[20:13] <Hiena> At 4800 baud, almost perfect square the communication signal on the audio in.
[20:14] <RocketBoy> I thought the audio in is AC coupled?
[20:15] <Hiena> Thought too. But seems it has very low frequency, so the 4.8k goes through.
[20:15] <Laurenceb> write something to detect the large changes in adc reading
[20:15] <Laurenceb> each one is the start of a bit
[20:16] <Laurenceb> then as you know your sample rate, you can count through to find the centers of your bits
[20:16] <Hiena> I wrote, and rejected the idea. Now i want to make a test with 12kHz carrier and stereo switching.
[20:17] <RocketBoy> I guess it would work for normal sequences of data - but you could get pathalogic sequences that would end up drifting the DC bias?
[20:17] <Laurenceb> if you only look at large changes, it shouldnt matter
[20:17] <Hiena> It would be much reliable.
[20:18] <Laurenceb> ie we say the input is 1, we see a large decrease, then it must be 0 and so on
[20:19] <Laurenceb> then we pass this "simulated logic level" to the next bit of code that acts like a normal uart
[20:20] <RocketBoy> yep OK#
[20:20] <Laurenceb> you'd need to set the delta_adc trigger level correctly, but it would be possible to have it adjust itself
[20:23] <Hiena> That was a reason, why i rejected the idea.
[20:24] <Laurenceb> you could correlate with a top hat function :P
[20:26] <Hiena> Much easier to do avgCh1-avgCh2 on n sample and see the results. I could sync the carrier to the communication, so the zero cross numbers will be same.
[20:28] <Hiena> That means, the whole process could be independent form the samplerate of the soundcard.
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[20:45] <fuzzylugnut> www.trossenrobotics.com
[20:45] <fuzzylugnut> they have lots of silicone wire.
[20:50] <Laurenceb> hey there
[20:52] <fuzzylugnut> hi :3
[20:54] <fuzzylugnut> they have some nice little gyros too.
[20:55] <fuzzylugnut> eventually I'd like to find one that would suit UROV inertial navigation.
[20:58] <akawaka> our balloons arrived
[20:58] <fuzzylugnut> yay!
[20:58] <fuzzylugnut> what size?
[20:58] <akawaka> fuzzylugnut: coupling transformer seemed to help with my radio problems yesterday
[20:58] <akawaka> 1200gram
[20:58] <fuzzylugnut> oh, glad to hear.
[20:59] <fuzzylugnut> when are you flying?
[20:59] <fuzzylugnut> how much gas do you use?
[20:59] <fuzzylugnut> : )
[20:59] <fuzzylugnut> what's the air speed velocity of an unladen swallow?
[21:00] <fuzzylugnut> (one of the guys at a job interview asked me that)
[21:00] <akawaka> an african or a european swallow?
[21:00] <fuzzylugnut> I don't know that!
[21:05] <fuzzylugnut> : )
[21:06] <fuzzylugnut> how heavy is your payload?
[21:13] <akawaka> aiming for about 1.5kg
[21:14] <fuzzylugnut> cool
[21:14] <fuzzylugnut> nice and light
[21:14] <fuzzylugnut> er
[21:14] <fuzzylugnut> lite : P
[21:14] <akawaka> aiming for a quick flight
[21:14] <fuzzylugnut> cutting down early?
[21:14] <akawaka> not a lot of open space around la surprisingly
[21:14] <akawaka> fuzzylugnut: no plans to, but we'll have a cutdown device
[21:14] <fuzzylugnut> Ok
[21:15] <fuzzylugnut> do you do any flight predictions?
[21:15] <akawaka> probably launch around fresno, winds should carry it south towards la
[21:15] <akawaka> yeah, been using the nearspaceventures online thing
[21:15] <akawaka> http://nearspaceventures.com/w3Baltrak/
[21:15] <akawaka> other suggestions are welcome
[21:15] <fuzzylugnut> cool, I use that too.
[21:16] <akawaka> find it accurate at all?
[21:16] <fuzzylugnut> Yeah, usually within about 10-20 miles each time for flights that travel 70-100 miles
[21:16] <akawaka> good to know
[21:17] <fuzzylugnut> we use the previous flight data to re-adjust the next flights prediction
[21:17] <fuzzylugnut> once we got within 5 miles
[21:18] <fuzzylugnut> what are you using for APRS transmitter?
[21:19] <akawaka> yaesu vx-3r
[21:19] <fuzzylugnut> and a tinytrak chip?
[21:20] <akawaka> no, pc104 linux box
[21:20] <akawaka> if we do another flight we'll probably use a microtrax, and then use the other radio for other telemetry
[21:21] <fuzzylugnut> Ok
[21:22] <fuzzylugnut> if I find the local repeater's call sign, can you put it in your digipath?
[21:22] <akawaka> yeah
[21:22] <akawaka> we weren't planning on using aprs, because we wanted to try to send some more complex telemetry, maybe some pictures
[21:22] <fuzzylugnut> ooh, ok
[21:22] <fuzzylugnut> gotcha.
[21:23] <akawaka> but now we're scared of losing everything, so we've decided to go with aprs
[21:23] <akawaka> :)
[21:23] <fuzzylugnut> lol
[21:23] <fuzzylugnut> yeah, redundancy ftw.
[21:24] <fuzzylugnut> I've flown the little microtrak-300's before, and I was able to receive more packets than the guys with the HT setup.
[21:24] <fuzzylugnut> they're pretty cheap too.
[21:25] <fuzzylugnut> in relation to the cost of loosing a payload, in most cases : P
[21:26] <fuzzylugnut> I'm very curious to see how that little linux boxen works for you.
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[21:28] <akawaka> me too
[21:29] <akawaka> hmmm
[21:29] <akawaka> maybe i should buy a microtrak
[21:29] <fuzzylugnut> when are you flying?
[21:30] <fuzzylugnut> http://www.byonics.com/microtrak/mt300.php
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[21:31] <fuzzylugnut> I've upgraded to the 8000FA ones because.... I can. and that our group can absolutly NOT loose our payload.
[21:31] <akawaka> fuzzylugnut: two weeks from now
[21:31] <fuzzylugnut> oooh, ok
[21:31] <fuzzylugnut> plenty of time then
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[21:33] <akawaka> hmm, $180
[21:33] <fuzzylugnut> on a stout 9v supply, you can get a 4+ watts out of them.
[21:34] <fuzzylugnut> when 300mw was very sucessful.
[21:34] <fuzzylugnut> however when its on the ground I wasn't able to pick up the 300 until I was 1/4 mile away.
[21:34] <fuzzylugnut> so.... just something to think about.
[21:35] <fuzzylugnut> (in comparison I was able to receive the 8000 3.5 miles away through town and buildings)
[21:36] <akawaka> what kind of antenna?
[21:36] <fuzzylugnut> bigass cartop
[21:36] <akawaka> on the micro-trak?
[21:38] <fuzzylugnut> Oh, just a little handheld andtenna, 1/4 wave vertical.
[21:40] <fuzzylugnut> sticking out the bottom of the payload.
[21:40] <fuzzylugnut> it didn't fair well on landing.
[21:41] <fuzzylugnut> do you have a yagi?
[21:42] <akawaka> getting one
[21:42] <fuzzylugnut> ok
[21:43] <fuzzylugnut> well I hope all goes well for you
[21:43] <fuzzylugnut> maiden voyage?
[21:43] <akawaka> yeah
[21:43] <fuzzylugnut> even better : ) all this functionality and its your first time.
[21:44] <natrium42> akawaka, you're launching in 2 weeks?
[21:44] <akawaka> fuzzylugnut: too much disposable income:)
[21:44] <akawaka> natrium42: thats the plan
[21:44] <natrium42> akawaka, cool, make live tracking for us :P
[21:45] <fuzzylugnut> yay for disposable income!
[21:45] <natrium42> fuzzylugnut, men like to play with toys
[21:45] <fuzzylugnut> indeed
[21:45] <natrium42> as they grow older, toys become more expensive
[21:46] <Laurenceb> any gcc users on here?
[21:46] <akawaka> sure
[21:46] <fuzzylugnut> yep
[21:46] <Laurenceb> ok, I was working on my radio system this morning
[21:46] <Laurenceb> if I printf some variables it works ok
[21:47] <Laurenceb> but if I dont it doesnt seem to be updating them correctly
[21:47] <Laurenceb> I'm using volatile
[21:47] <akawaka> code?
[21:47] <akawaka> compiling with any optimization options?
[21:47] <Laurenceb> http://pastebin.com/m41428551
[21:47] <Laurenceb> -os
[21:48] <akawaka> which printfs?
[21:48] <natrium42> akawaka, are you going to use radio or cellphone?
[21:48] <Laurenceb> so if I turn on printf debugging
[21:48] <Laurenceb> ie #define debug
[21:48] <Laurenceb> it works
[21:49] <Laurenceb> otherwise, when it wakes up, the first character is corrupted
[21:49] <akawaka> whats with this printf( "waiting..." code
[21:49] <akawaka> sbi in the debug block, but cbi in the not debug block
[21:49] <Laurenceb> I'm using volatiles for the variables shared between the main code and overflow
[21:49] <Laurenceb> which is an ISR
[21:50] <Laurenceb> waiting shows its waiting for data
[21:50] <Laurenceb> sbi versus cbi inverts the level of the enable output
[21:50] <Laurenceb> its for debugging perposes
[21:51] <akawaka> okay
[21:51] <akawaka> sure that kind of stuff isn't the issue, and not the printfs?
[21:51] <Laurenceb> http://pastebin.com/me8de555
[21:52] <Laurenceb> maybe, but from past experience the problem points to a volatile being needed
[21:52] <Laurenceb> but all the variables in the ISR are volatile
[21:54] <Laurenceb> after it wakes up, the first byte or two isnt correct... the pwm output is ok, but the logic levels aren't
[21:56] <Laurenceb> so the first byte always has the last 4 bits=1, and the seconds sometimes misses a start bit
[21:58] <Laurenceb> any ideas?
[21:58] <akawaka> maybe the static bufone might be a problem
[21:58] <akawaka> doubt it
[21:58] <Laurenceb> thats to set the pwm as soon as possible
[21:59] <akawaka> only one overflow can be called at once, right?
[21:59] <Laurenceb> yes, the other timers are off
[22:00] <akawaka> where does pulse_res_minus1 come from/
[22:00] <Laurenceb> table.h
[22:00] <Laurenceb> its not on pastebin, its dynamically generated
[22:00] <Laurenceb> by the makefile
[22:00] <akawaka> doesn't change?
[22:01] <Laurenceb> only if you change F_CPU, its a lookup
[22:02] <akawaka> the atomic block stuff disables the timer?
[22:03] <Laurenceb> no, only interrrupts I think
[22:03] <akawaka> okay, but overflow won't get called in those blocks?
[22:03] <Laurenceb> shouldnt
[22:03] <Laurenceb> but if it does it shouldnt matter
[22:03] <Laurenceb> it will get serviced later?
[22:05] <Laurenceb> hmm maybe I should look at that
[22:05] <akawaka> you could have some non-atomic update issues, but i'm not sure i see anything serious
[22:06] <akawaka> timer1overflows might not always be correctly set to 0
[22:07] <akawaka> its a uint, what size is that 16-bits? can it be written in a single operation?
[22:07] <Laurenceb> no
[22:08] <Laurenceb> your thinking the tuneup function?
[22:08] <akawaka> no, all the other points where you set it to 0
[22:09] <Laurenceb> like in send ?
[22:09] <akawaka> yeah
[22:09] <Laurenceb> but that uses atomic?
[22:09] <Laurenceb> so it should copy ok right?
[22:10] <akawaka> i don't know what those atomic macros do
[22:11] <Laurenceb> its supposidly for things like this where you want to copy over large variables without interruption
[22:13] <akawaka> you should assert that that is what is happening
[22:13] <Laurenceb> what do you mean?
[22:14] <Laurenceb> comments?
[22:14] <akawaka> if you are unsure what those atomic macros are doing you should add some debug code to make sure that overflow isn't being called when you think it shouldn't be
[22:15] <Laurenceb> right
[22:15] <akawaka> add a volatile u8 shouldnt_be_in_overflow;
[22:15] <Laurenceb> eh where?
[22:16] <Laurenceb> what line?
[22:16] <akawaka> set it to true at the start of the atomic blocks and false at the end
[22:16] <akawaka> in overflow, make sure that value is always false
[22:18] <Laurenceb> ok
[22:19] <Laurenceb> I seem to have it working atm, but with the power saving code commented out as in the pastebin code
[22:29] <Laurenceb> bbl, thanx for the advice
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[22:51] <fuzzylugnut> word.
[22:59] <fuzzylugnut> one of the guys on our group is machining up a mold for out cutdown devices.
[23:00] <fuzzylugnut> so we can have good quality control over the placement of the charge and rope.
[23:01] <fuzzylugnut> ....and it means that I get to set off a bunch to make sure the new mold works : 3
[23:11] <jcoxon> fuzzylugnut, how does your cutdown work?
[23:11] <jcoxon> nichrome?
[23:13] <fuzzylugnut> I use liquid plastic to bond two little ropes together. At the center is a small charge of smokeless powder to burst it all apart.
[23:16] <jcoxon> oh right, quite like our pyro cutdowns
[23:16] <fuzzylugnut> cool, you use a similar method?
[23:16] <edmoore> yep
[23:17] <jcoxon> http://wiki.ukhas.org.uk/ideas:flight_support#pyrotechnic_cutdown_device
[23:17] <jcoxon> but i think there is more blackpowder these days
[23:17] <fuzzylugnut> Oh, yeah, cool
[23:19] <fuzzylugnut> I'm guessing the tube is something that shatters easy?
[23:25] <fuzzylugnut> like, acrylic or something?
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[23:34] <fuzzylugnut> oh
[23:34] <fuzzylugnut> dur.
[23:34] <fuzzylugnut> hard plastic : P
[23:34] <fuzzylugnut> heee.... I guess I should actually read things : )
[23:36] <akawaka> i wonder would a blob of epoxy with the igniter and the rope embedded in it work
[23:37] <akawaka> need to find a gps module
[23:37] <fuzzylugnut> GPS-18-LVC
[23:37] <fuzzylugnut> thats what I use.
[23:38] <edmoore> the lassen iq is recommended too
[23:38] <fuzzylugnut> akawaka: depends on alot of things, such as the thickness of your rope, how much heat is created by the igniter...etc...
[23:38] <fuzzylugnut> *searches the lassen iq*
[23:38] <akawaka> fuzzylugnut: works at high altitude?
[23:39] <edmoore> sparkfun sell them
[23:39] <edmoore> they work all the way up
[23:39] <fuzzylugnut> *concur* : )
[23:39] <edmoore> the data sheet explicitly statesw their suitability for scientific balloons, infact
[23:41] <fuzzylugnut> wow, tiny!
[23:41] <edmoore> nice pacage too, easy connector to solder
[23:43] <akawaka> what kind of antenna would you stick on there?
[23:43] <edmoore> they have this hfl? or whatever it's called connector
[23:43] <edmoore> but we just use these
[23:44] <edmoore> http://www.sparkfun.com/commerce/product_info.php?products_id=178
[23:46] <natrium42> sparkfun'd
[23:46] <fuzzylugnut> hehe.
[23:46] <edmoore> yup :)
[23:46] <jcoxon> i should add a !sparkfun function to zeusbot
[23:46] <fuzzylugnut> haha
[23:47] <jcoxon> after google its the next thing we search for
[23:47] <natrium42> they get a lot of money from us
[23:47] <fuzzylugnut> : ) neat. I have not heard of them until now
[23:47] <fuzzylugnut> my paycheck goes to digikey.
[23:48] <natrium42> yep, digikey too
[23:48] <edmoore> you can't do balloons without sparkfun!
[23:48] <jcoxon> fuzzylugnut, sparkfun!
[23:48] <fuzzylugnut> heee...
[23:49] <akawaka> this balloon project is not cheap
[23:50] <akawaka> whichever migrant farmer finds it in the central californian farmlands will be very happy
[23:50] <jcoxon> akawaka, they get cheaper if they work
[23:50] <natrium42> and you end up buying more than you need
[23:50] <jcoxon> oh i've heard of stories of massive scientific payloads being stripped down
[23:50] <natrium42> akawaka, no risk no gain
[23:50] <fuzzylugnut> lol
[23:50] <jcoxon> they even used the case as a house
[23:50] <natrium42> haha
[23:50] <fuzzylugnut> ....were they mice?
[23:51] <jcoxon> no these were 200kg+ payloads
[23:51] <fuzzylugnut> oooh, ok
[23:53] <fuzzylugnut> speaking of, one of those huge mylar balloons was on ebay a few months ago
[23:53] <fuzzylugnut> 22kg
[23:53] <edmoore> wow
[23:54] <jcoxon> fully packaged?
[23:55] <fuzzylugnut> ina box
[23:55] <jcoxon> wow
[23:55] <fuzzylugnut> yeah, lotsa heliums : )
[23:56] <fuzzylugnut> plus they just plain look awesome.
[23:57] <jcoxon> helium:
[23:57] <jcoxon> http://www.flickr.com/photos/jcoxon77/337394043/in/set-72157594446369581/
[23:58] <fuzzylugnut> :o
[23:58] <fuzzylugnut> damn.
[23:58] <jcoxon> there were 2 of those trailers
[23:58] <edmoore> i'm not looking at the helium...
[23:58] <jcoxon> haha
[23:59] <fuzzylugnut> hah : )
[00:00] --- Tue Mar 18 2008