highaltitude.log.20100922

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[00:05] <SpeedEvil> If you cheat - and just have 4 phases, it can be done with a big diode array
[00:06] <chris_99> do you have any links regarding that SpeedEvil, sounds very interesting
[00:11] <chris_99> am right in thinking the reason for beamforming is to get greater reception by simulating a larger antenna (after a quick browse of wikipedia)
[00:11] <Randomskk> well in general yes
[00:11] <Randomskk> but it's more a case of
[00:11] <Randomskk> uh
[00:11] <Randomskk> shaping the radio beam
[00:12] <Randomskk> going from an omnidirectional transmission or reception
[00:12] <Randomskk> to a directed beam of transmission or reception
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[00:12] <Randomskk> which improves gain or signal, depending on which side you're on
[00:12] <Randomskk> it's like cupping your hands around your mouth to shout at someone
[00:12] <SpeedEvil> No, I don't, I'm just commenting from knowledge of the general idea.
[00:12] <Randomskk> instead of just shouting, which goes out kinda forwards all over the place
[00:12] <chris_99> aha, so its like having a dish, but without the dish?
[00:13] <Randomskk> something like that
[00:13] <Randomskk> a dish is still beamforming, just you can't change it
[00:13] <chris_99> cool, so you could in theory replace you're sat dish with a beamforming array
[00:13] <chris_99> *your
[00:13] <Randomskk> but if you have a lot of antennas and computer control the phase shift and amplitude going out of each, their interference will create a beam that you can direct
[00:14] <Randomskk> you could. it'd be pointless given as geostationary satellites for tv are kind of stationary in the sky
[00:14] <Randomskk> but for things that move, it's kinda neat.
[00:14] <chris_99> so the beam can move while the antennas are stationary
[00:14] <Randomskk> yea
[00:14] <chris_99> thats amazing!
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[00:15] <chris_99> so could the transmitter on the balloon be just a normal 433MHz transmitter and the reciever could use beamforming
[00:15] <chris_99> or would it be best for both devices to use it
[00:15] <Randomskk> we already do - all the receivers have yagis
[00:16] <Randomskk> the antennas that look like TV antennas
[00:16] <Randomskk> e.g. |-|-|-|-i
[00:16] <Randomskk> they provide a high directional gain
[00:16] <Randomskk> you just point them at the balloon
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[00:17] <Randomskk> doing electronic beamforming isn't really worth it on the ground side. we can point yagis good.
[00:17] <Randomskk> but on the balloon, pointing is a right pain
[00:18] <chris_99> aha, i get you, so you'd have the array of antennas on the balloon
[00:18] <Randomskk> yea.
[00:18] <Randomskk> and then electronically control the phase (and amplitude) to each
[00:18] <Randomskk> thus beamforming, which you could direct towards the receiver
[00:18] <Randomskk> massively improving their signal
[00:18] <Randomskk> potentially enough to allow for much higher baud rates, which means more data
[00:18] <chris_99> so you'd beacon you're GPS long/lat to it, and it'd work out where to send it
[00:19] <Randomskk> well probably you'd store your position on it before launch, to start with at least
[00:19] <Randomskk> but yes
[00:19] <Randomskk> it would know where you were, and its GPS tells you where it is and its magnetometer tells it what direction it's facing
[00:19] <Randomskk> it does maths to work out where to point
[00:20] <chris_99> so it still uses one carrier frequency but uses different phased waves
[00:20] <chris_99> from each antenna
[00:20] <Randomskk> SpeedEvil: looks like it can be done either by generating one source signal, splitting it to many antennas through a programmable phase delay
[00:20] <Randomskk> or by using many transmitters, all synced to a central clock, and controlling each transmitter's output
[00:21] <Randomskk> I don't imagine syncing many NTX2s would be very easy :P
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[00:31] <chris_99> http://tempest.das.ucdavis.edu/mmwave/PAA/PAA.htm - looks rather complex!
[00:31] <Randomskk> it is quite complicated I think
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[00:46] <SpeedEvil> Argh - stupid internets.
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[01:31] <chris_99> can anyone suggest a cheap 433MHz reciever/transmitter similar to Yaesu FT-790R
[01:31] <Randomskk> eh. there's not much cheaper. the ft817 is nice
[01:32] <chris_99> cheers i'll check that one out, i couldn't find the yaesu on ebahy
[01:32] <chris_99> *ebay unfourtunately
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[01:33] <chris_99> ah thats not on either heh
[01:34] <chris_99> do these types of radio transmitters have a name?
[01:34] <chris_99> i'm not exactly sure what i should be googling
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[08:05] <Darkside> juxta: http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs669.snc4/60966_1620756235826_1144042127_1732901_5151141_n.jpg
[08:06] <juxta> nice work Darkside :D
[08:06] <juxta> 40mW out?
[08:07] <juxta> what's halfway down the coax - looks like maybe an attenuator from some diodes?
[08:09] <Darkside> low pass filter
[08:09] <Darkside> get rid of the clock feedthrough
[08:10] <Darkside> currently it has a cutoff frew of about 12MHz, but im going to make one with a cutoff of 14MHz - then I can use the 13MHZ ISM band
[08:10] <Darkside> i'm allowed to do 100mW on that ISM band
[08:10] <juxta> ah righto, awesome :)
[08:10] <juxta> we have a launch on 10/10/10
[08:10] <juxta> want to fly it then?
[08:11] <Darkside> lol, not in that configuration..
[08:11] <Darkside> it will break
[08:12] <Darkside> if i can get the filter into the same box as the amp, then maybe
[08:12] <Darkside> i also need to wire up some sensors to the Xmega - currently it has nothing
[08:13] <Darkside> im thinking i'll hook up my UBlox5 GPS module, and a DS18B20 temp sensor
[08:13] <Darkside> then steal your code and adapt it to the xmega :P
[08:36] <m1x10> good morning :)
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[08:58] <DagoRed> last DSP problem for the night..
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[09:30] <Laurenceb> hi
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[09:54] <SpeedEvil> ih
[09:56] <Upu> Darkside http://milesburton.com/index.php?title=Dallas_Temperature_Control_Library#Supported_Devices for the DS18B20
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[10:44] Action: Laurenceb is confused by usb sheilds
[10:45] <Laurenceb> http://www.ti.com/sc/docs/apps/msp/intrface/usb/emitest.pdf
[10:45] <Laurenceb> figure 12 shows shield -> gnd plane.. i dont get it
[10:46] <Laurenceb> http://uk.farnell.com/images/en/ede/pdf/usb_dev_mistake.pdf
[10:46] <Laurenceb> figure 7 wtf
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[11:03] <m1x10> Anyone used www.pcbcart.com before?
[11:06] <nv1k> nope
[11:06] <nv1k> 2 layer or more?
[11:08] <m1x10> http://pcbcart.com/support/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=4&nav=0
[11:08] <Darkside> Upu: not an arduino
[11:08] <Darkside> using an xmega
[11:08] <Darkside> apparently DanielRichman has code for it
[11:10] <nv1k> i generally get all of my 2 layer boards done via advanced circuits
[11:10] <nv1k> 33 dollars
[11:11] <m1x10> http://www.advancedcircuits.co.nz ?
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[11:11] <nv1k> http://www.4pcb.com/index.php?load=content&page_id=130
[11:13] <m1x10> 33$ each ?
[11:14] <m1x10> seeedstudio is 40$ for 10pcs
[11:15] <nv1k> 33 each for 60sq in
[11:16] <nv1k> you were wanting a custom pcb?
[11:16] <m1x10> http://www.seeedstudio.com/depot/fusion-pcb-2-layer-5cm5cm-max-10pcs-p-513.html?cPath=64_12
[11:17] <m1x10> yes custom pcb
[11:18] <nv1k> those are <2x2" maximum
[11:19] <m1x10> 2x2 what?
[11:19] <m1x10> 5x5cm ?
[11:19] <nv1k> the " means inches
[11:19] <nv1k> but yeah, equivalent to 5cm
[11:20] <nv1k> if that is as big as you need use them
[11:20] <m1x10> yeah
[11:20] <nv1k> the advanced circuits deal is up to 60 sq inches
[11:20] <m1x10> arduino compatible sized
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[11:57] <Laurenceb> ooh my seeedstudio boards are in the UK
[11:57] <Laurenceb> should arrive tomorrow :P very fast
[11:58] <Laurenceb> about 8 days total from order to delivery
[11:58] <nv1k> not bad
[11:59] <SpeedEvil> :)
[11:59] <SpeedEvil> this is the autopiloty thing.
[12:00] <Laurenceb> yes
[12:00] <nv1k> silly FAA
[12:01] <Laurenceb> "RELEASED BY CLEARING AGENCY. NOW IN-TRANSIT FOR DELIVERY " hope that means no customs
[12:02] <Laurenceb> was only posted last night - went straight out of HK airport
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[12:18] <Darkside> hmm
[12:18] <Darkside> DanielRichman: about?
[12:21] <Darkside> or juxta
[12:21] <juxta> hey
[12:21] <Darkside> do you have a HF antenna up?
[12:21] <juxta> sadly no
[12:21] <juxta> should string one up
[12:21] <Darkside> heh
[12:21] <Darkside> im putting 40mW out at 7.5MHz..
[12:22] <Darkside> maybe i should move to something that isn't in the middle of a nowhere band :/
[12:22] <juxta> hehe
[12:22] <Darkside> its currently going into a 51 ohm resistor
[12:22] <nv1k> heh
[12:22] <Darkside> domino is working pretty well, too
[12:22] <Darkside> but it takes a little while to get sync
[12:23] <juxta> nice work :)
[12:23] <Darkside> ok now its transmitting RTTY300
[12:25] <Darkside> well, it works
[12:25] <Darkside> of course using an actual antenna will help
[12:26] <Darkside> now i need to write some code to let me modify settings on the fly
[12:26] <russss> http://www.bbc.co.uk/blogs/thereporters/jonathanamos/2010/09/it-is-one-of-those.shtml
[12:27] <nv1k> soo much hydrogen
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[12:28] <nv1k> riding on a bomb, yay
[12:42] <chris_99> they quote it as being 40 times safer than the shuttle
[12:42] <chris_99> in http://www.reactionengines.co.uk/splm_movie_flash.html
[12:43] <nv1k> well that doesn't really take a whole lot to do lol
[12:43] <nv1k> i'm sure it is safe
[12:43] <nv1k> baring any freak collisions
[12:44] <chris_99> heh
[12:44] <nv1k> stil not exactly where i would want to be sitting
[12:44] <SpeedEvil> 40 times safer is a complete lie.
[12:44] <chris_99> i wouldn't have a clue how you'd go about calculating something like that
[12:45] <SpeedEvil> You basically pull numbers out of your ass a lot.
[12:45] <SpeedEvil> It's like the drake equation.
[12:45] <Laurenceb> itsa interesting
[12:45] <Laurenceb> but the engine design seems mad
[12:45] <SpeedEvil> The errors compound.
[12:45] <nv1k> lol drake equation
[12:46] <Laurenceb> JAXA have a way more sensible engine operating on the same principles
[12:46] <Laurenceb> and they have built prototypes
[12:46] <Laurenceb> unlike reaction
[12:46] <SpeedEvil> For example - what is the chances of a gear failure at takeoff killing it.
[12:46] <Laurenceb> the helium loops are just mental
[12:46] <nv1k> Nuclear Lightbulb man! Way of the future
[12:46] <SpeedEvil> Times what's the chance of a massive birdstrike killing it
[12:46] <SpeedEvil> Space-x
[12:46] <nv1k> if you think helium loops are mental look at the nuclear lightbulb
[12:46] <SpeedEvil> space-x are comparatively awesome and completely sane.
[12:47] <Laurenceb> also they dont seem to have deisgned an airframe
[12:47] <nv1k> it involves the phrase "white hot flourine gas"
[12:47] <Laurenceb> they have some deisgn work and some very accurate mass figures
[12:47] <SpeedEvil> Laurenceb: Also - the airframe is _fucking_hard_
[12:47] <Laurenceb> but no detailed design work to show where they got them from
[12:47] <Laurenceb> its a lot easier than space shuttle
[12:47] <SpeedEvil> Space-s's 'airframe' is _really_ simple.
[12:48] <nv1k> well it hope it is hard, wouldn't want it to fall apart ;)
[12:48] <Laurenceb> and its very modular
[12:48] <SpeedEvil> You can easily do it on a spreadsheet almost.
[12:48] <SpeedEvil> space-x
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[12:48] <Laurenceb> no very large bits of CF
[12:48] <Laurenceb> its based on interchangable CF truss structure
[12:48] <Laurenceb> with silicon carbide composite or something
[12:48] <Laurenceb> over the top
[12:49] <Laurenceb> then alu tanks suspended inside
[12:49] <SpeedEvil> Yes it does.
[12:49] <Laurenceb> seems to solve a lot of problems, but their mass estimates are crazy light
[12:49] <Laurenceb> and very accurate
[12:49] <SpeedEvil> The risk of death from space shuttle is of the order of - probably - if they were to continue flying them - 0.5%
[12:49] <Laurenceb> i dont believe they didnt just cunjor them up
[12:50] <Laurenceb> i asked them if they had detailed airframe design work and "its not what the company is focussed on"
[12:50] <SpeedEvil> I remember another solution with conformal hydrogen tanks, and odd shapes, and wierd engines that would reduce the cost of space-launch.
[12:50] <SpeedEvil> X-33/venture-star.
[12:50] <SpeedEvil> That went well.
[12:51] <Laurenceb> skylon is a lot more sensible airframe wise it seems..
[12:51] <nv1k> well with an experienced structural engineer you can get a size and a required loading and they will have a pretty decent idea of what it will weigh
[12:51] <SpeedEvil> The airframe looks like an aerospace companies wet-dream.
[12:51] <Laurenceb> engine wise skylon is mad
[12:51] <SpeedEvil> In that it's lovely and innovative and complex and expensive.
[12:51] <Laurenceb> CF is cheap
[12:51] <Laurenceb> itsd the moulding thats hartd
[12:52] <SpeedEvil> Except, Reaction Engines say they have developed an anti-frost solution that will allow the heat exchangers to run and run.
[12:52] <SpeedEvil> Screw space-launch.
[12:52] <SpeedEvil> Go into aircon
[12:52] <Laurenceb> skylon seem to think you can get around a l0ot of CF moulding problems by using interchangable and small CF parts
[12:53] <Laurenceb> its basically a load of CF tube
[12:53] <Laurenceb> in a funcky space frame deisgn inside
[12:53] <SpeedEvil> That does not sound in principle insane.
[12:53] <Laurenceb> the outside isnt structural
[12:53] <SpeedEvil> But it has obvious implications for structural redundancy
[12:53] <Laurenceb> and the alu tanks are very thin and under tension
[12:54] <Laurenceb> using nomex ties
[12:54] <Laurenceb> onto the CF tubes - theres also multifoil insulation strung between
[12:54] <Laurenceb> then outer covering of as funcky silicon carbide composite insulation in largish panels
[12:55] <Laurenceb> *a
[12:55] <SpeedEvil> Interesting.
[12:55] <Laurenceb> one question thery couldnt answer is how the outer TPS is bolted on
[12:55] <Laurenceb> without the bolts melting :P
[12:55] <SpeedEvil> Iridium bolts.
[12:56] <SpeedEvil> It's what makes up $500m of the price of each vehicle.
[12:56] <Laurenceb> also as i said the airframe was all blah this and blah that - no design work with actual calculations in sight
[12:56] <Laurenceb> apart from a mass estimate to 4 significant figures :P
[12:56] <nv1k> the calculations are trade secret
[12:57] <SpeedEvil> Sure.
[12:57] <SpeedEvil> Great.
[12:57] <SpeedEvil> But not with my taxes.
[12:57] <SpeedEvil> (neglecting for the moment that I'm not paying taxes right now)
[12:57] <nv1k> apparently yes with your taxes
[12:57] <Laurenceb> they feed SpeedEvil with my taxes
[12:58] <nv1k> but i agree, that design seems insane
[12:58] <nv1k> which is why i needs to happen
[12:58] Action: Laurenceb runs away
[12:58] <nv1k> *it needs
[12:58] <SpeedEvil> You can get _well_ under an order of magnitude lower than current launch costs with conventional engines.
[12:58] <SpeedEvil> And RP1/LOX
[12:58] <SpeedEvil> The key is to keep all of the people that worked on NASA designs and ICBMs out of it.
[12:58] <Laurenceb> http://datasheets.maxim-ic.com/en/ds/MAX4291-MAX4294.pdf
[12:58] <SpeedEvil> their 'shave weight at any cost' mentality is insane.
[12:59] <Laurenceb> nice - dual opamps in 1.5mm square BGA
[12:59] <nv1k> BGA != nice
[12:59] <Laurenceb> its not too bad in small pincount
[12:59] <SpeedEvil> Umm - the ITG-3200 - I seem to remember you mentioning that there is a version with an onboard accel
[12:59] <SpeedEvil> But I can't seem to find it.
[13:00] <Laurenceb> no, onboard processing
[13:00] <Laurenceb> its on the invensens site
[13:00] <SpeedEvil> ah - yeah - hooked to one oddball accel that I can't seem to find in stock
[13:00] <nv1k> What are you working on designing?
[13:01] <SpeedEvil> I'm personally working at jamming a better accel, a magnetometer, and a gyro into my phone.
[13:01] <nv1k> hehehehe
[13:01] <m1x10> Who can dedicate some of his time examining my-first-ever mobo schematic for potential problems ??
[13:02] <SpeedEvil> Laurenceb has been working on a autopilot thing with lots of sensors and outputs.
[13:02] <nv1k> nice
[13:02] <nv1k> my autopilot is minimal sensors
[13:02] <nv1k> and only 2 outputs cause its a parafoil descent autopilot
[13:03] <nv1k> assuming FAA will let it fly...
[13:03] <Laurenceb> nv1k: interesting
[13:03] <Laurenceb> i worked on a rogaLLO
[13:03] <Randomskk> m1x10: if you post a link, people will probably have a quick look
[13:04] <Laurenceb> just gyro anbd gps - kept it simple
[13:04] <nv1k> this project is magnetometer and gps
[13:04] <nv1k> at the moment
[13:04] <nv1k> may add accel later since it is so cheap now
[13:06] <m1x10> Here is the link to the image: http://imagebin.org/115172
[13:06] <Laurenceb> you really need a gyro imu
[13:06] <Laurenceb> *imo
[13:06] <m1x10> plz any feedback would be great
[13:06] <Laurenceb> tho a magno will give you useful data
[13:06] <nv1k> well the guided parafoil really only needs to know position and heading
[13:07] <Laurenceb> heading rate is really needed
[13:07] <nv1k> it is essentially a 2d guidance problem
[13:07] <Laurenceb> for the PID controller
[13:07] <Laurenceb> if you are aligned with the B field vector
[13:07] <Laurenceb> magno wont give you rotation rate
[13:08] <nv1k> simulations showed that for this application a PI controller provides acceptable results
[13:08] <Laurenceb> just a sec
[13:08] <nv1k> whole premise of the project is minimum complexity
[13:08] <Laurenceb> ill find a photo
[13:08] <Laurenceb> yeah mine too
[13:08] <Laurenceb> but i did flight tests
[13:08] <Laurenceb> lots- it seemed a gyro was needed
[13:08] <Laurenceb> parafoils especially are very twitchy
[13:09] <nv1k> m1x10 you generally use pullup resistors on i2c lines
[13:09] <Laurenceb> http://i.imgur.com/Xw9Ge.jpg
[13:10] <Laurenceb> thats my rogallo tronics compartment
[13:10] <nv1k> what was your wing loading?
[13:10] Action: Laurenceb looks it up
[13:10] <m1x10> nv1k the sensor breakout already contains the pullups.
[13:10] <nv1k> m1x10, ok
[13:11] <Laurenceb> almost exactly 100N/m^2
[13:11] <m1x10> http://www.sparkfun.com/commerce/product_info.php?products_id=9694
[13:11] <Laurenceb> nv1k: i used mlx90609 gyro
[13:11] <Laurenceb> very good temperature stasbility
[13:11] <Laurenceb> and digital
[13:11] <Laurenceb> then atmega168 + ntx2 - not shown there its on another module
[13:12] <Laurenceb> and lassen iq gps
[13:12] <Laurenceb> then CofG shift using the servo winch
[13:13] <nv1k> ah
[13:13] <Laurenceb> theres a corona dsp receiver in there so you can fly it from the ground
[13:13] <nv1k> mine isn't weight shift
[13:14] <nv1k> yaw control via flap deflection
[13:14] <Laurenceb> ah
[13:14] <nv1k> and at a somewhat higher wing loading
[13:15] <Laurenceb> yeah thats common with parafoils
[13:15] <Laurenceb> http://i.imgur.com/Sa5LJ.jpg
[13:15] <nv1k> which should alleviate some of the 'twitchyness'
[13:15] <Laurenceb> thats the ntx2 board before it was populated
[13:15] <Laurenceb> where are you?
[13:16] <nv1k> USA
[13:16] <Laurenceb> ah ok
[13:17] <nv1k> Premise of the project is minimum complexity GNC solution to land HAB payload at a specified point
[13:19] <Laurenceb> just a sec ill upload video
[13:20] <nv1k> my prelim simulations indicated the addition of a gyro and switching to PID instead of PI yielded <2m average accuracy improvement
[13:22] <Laurenceb> hmm
[13:22] <Laurenceb> how were you simulating the foil?
[13:23] <nv1k> treated as a curved cambered wing
[13:24] <nv1k> tested against full CFD model to establish bounds
[13:24] <Laurenceb> sounds impressive
[13:25] <nv1k> heh, i had nothing to do with the CFD
[13:25] <Laurenceb> but parafoils can flex and do all sorts of weird stuff
[13:25] <Laurenceb> id want to do some real world testing
[13:25] <nv1k> yeah thats what the CFD was for, to establist our max alpha/beta conditions
[13:25] <nv1k> *establish
[13:25] Action: Laurenceb just goes for the launch it down a hill approach
[13:26] <nv1k> heh
[13:26] <nv1k> it was the middle of winter :)
[13:26] <nv1k> and it was the prof's idea
[13:27] <Laurenceb> so how do you derive heading from the magno?
[13:27] <nv1k> magno is used to determine body orientation
[13:27] <nv1k> high rate gps for actual flight path heading
[13:28] <nv1k> when the payload is first released it flys 2 complete circles
[13:28] <nv1k> to get an average value for it airspeed
[13:28] <nv1k> then does a vector sum of airspeed,body angle, and gps velocity to determine the wind velocity
[13:29] <Laurenceb> ah thats one approach
[13:29] <Laurenceb> i just record during the ascent
[13:29] <Laurenceb> then have 200m thick layers
[13:29] <nv1k> yeah
[13:30] <Laurenceb> during descenty it works out the estimated windspeed by interpolating the nearest layers
[13:30] <nv1k> part of the project definition was no initial data
[13:30] <Laurenceb> i see
[13:30] <nv1k> otherwise yeah we would do that
[13:30] <Laurenceb> you can work out the wind vector
[13:30] <Laurenceb> using attitude data and gpos
[13:30] <Laurenceb> *gps
[13:30] <Laurenceb> but that technique is sensitive to nnoise
[13:31] <nv1k> yeah but for minimum complexity
[13:31] <Laurenceb> when i simulated it it was outperformed by the record during ascent algorythm
[13:31] <nv1k> no doubt
[13:31] <Laurenceb> - simulated it using actual flight data
[13:31] <nv1k> i won't contest the record during ascent is a better method
[13:32] <nv1k> its just for this specific project we are unable to assume any knowledge of wind data
[13:32] <Laurenceb> if you have magno and gps and gyro
[13:32] <Laurenceb> you can work out wind data quite well
[13:32] <nv1k> yes
[13:33] <nv1k> our simulations showed that it didn't make an appreciable difference
[13:33] <Laurenceb> in fact if you can get into stabnle flight using your technique you can easily work out a very good estimate if you know the cruise speed
[13:33] <nv1k> yeah thats the premise
[13:33] <Laurenceb> i see
[13:33] <nv1k> after parafoil is fulled deployed/dereefed
[13:33] <nv1k> low rate turn through two circles to get an avg airspeed
[13:34] <nv1k> then vector sums to determine wind
[13:34] <nv1k> if the first few actual tests don't give the results we want, adding a gyro is a trivial matter
[13:34] <nv1k> in terms of hardware
[13:35] <nv1k> software it would ideally just be deriving new control gains and switching to PID but it is never actually that simple
[13:36] <nv1k> but hopefully the no gyro configuration gives acceptable results
[13:36] <nv1k> 50m CEP is more than acceptable for us
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[13:37] <SpeedEvil> Airspeed when turning will drop won't it?
[13:38] <nv1k> primarily as a function of sideslip
[13:39] <nv1k> as long as the turns remain low-rate the constant airspeed assumption is within 5%
[13:40] <nv1k> i mean ideally you would account for it
[13:41] <Laurenceb> yeah
[13:42] <nv1k> but the only time we should encounter a high rate turn is if we enter a terminal spiral over the target point
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[13:42] <nv1k> and if that happens, I want the airspeed to drop
[13:51] <Laurenceb> http://vimeo.com/15190485
[13:52] <nv1k> will have to watch that when it finishes converting
[13:52] <nv1k> thanks
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[14:02] <nv1k> so was that a university project?
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[14:03] <nv1k> @Laurenceb
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[14:09] <Laurenceb> no
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[14:10] <nv1k> well time to resume my CAD work
[14:10] <nv1k> thanks for the discussion
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[14:39] <Laurenceb> nv1k: are you using self tuning control loops?
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[15:02] <Laurenceb> mine was rather simpler in that respect - theres some vaguely documented code here http://ukhas.org.uk/code:parafoil_main
[15:02] <Laurenceb> ooh its loaded http://vimeo.com/15190485
[15:25] <Randomskk> is that ed I can hear going "you have to run, laurence!"
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[16:03] <natrium42> o/
[16:05] <natrium42> who again was making the iphone tracker app?
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[16:14] <SpeedEvil> Upu ?
[16:14] <SpeedEvil> I forget
[16:22] Action: natrium42 pokes Upu
[16:23] <natrium42> IN THE EYE
[16:28] <DanielRichman> natrium42: 21:06 < Upu> hows the iphone tracker coming on ?
[16:28] <DanielRichman> 21:08 < JackNorris> good, still working with the UI
[16:28] <natrium42> ah, cool
[16:28] <DanielRichman> that's not from today
[16:29] <DanielRichman> ages ago. But that's who it is
[16:31] <SpeedEvil> oh
[16:33] <Upu> I badger him every day
[16:34] <Upu> its got a memory leak apparently but he's still working on it
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[16:35] <SpeedEvil> You need to anger the badgers first.
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[17:56] <jcoxon> evening
[18:08] <fsphil> hiya jcoxon
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[18:10] Nick change: laurence_ -> Laurenceb_
[18:10] <Laurenceb_> hi
[18:10] <jcoxon> hey
[18:25] <jcoxon> bbl
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[18:50] <fsphil> cool, the caa have replied!
[18:52] <SpeedEvil> Positively?
[18:52] <fsphil> very
[18:53] <fsphil> basically saying they've been very busy, and would like to delay my start date a little -- but otherwise no problems
[18:53] <SpeedEvil> Woo!
[18:54] <fsphil> I needa get working!
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[19:26] <Upu> Nice one fsphil :)
[19:26] <Upu> Anyone want to have a scan at this and tell me if I've made any noobie mistakes : http://ava.upuaut.net/files/atmega.jpg / http://ava.upuaut.net/files/avav1.png
[19:28] <DanielRichman> Upu: do you not need to connect power to the external temperature sensor too?
[19:28] <DanielRichman> also; did you route that manually or use the autorouter?
[19:28] <Upu> no it's using parasitic power
[19:29] <Upu> autoroute apart from the SMA connector
[19:29] <natrium42> where is the ground layer? :P
[19:29] <Upu> oh yeah I have to surround it in ground don't I
[19:29] <Upu> meh :)
[19:29] <natrium42> also, traces look kinda thin
[19:29] <DanielRichman> yeah you can use parasitic power but in some ways it's easier to just supply +5v or whatever it takes
[19:29] <natrium42> you can at least thicken the power traces
[19:29] <Upu> http://milesburton.com/images/e/e5/Schematic-dallas-18s20.gif
[19:29] <Upu> that's what I'm using and it seems to work
[19:30] <DanielRichman> yes that's my other point; the traces are their thinnest when you could probably route the whole thing with 0.4 traces
[19:30] <Upu> ok it's my first attempt so looking for some guidance thx
[19:31] <Upu> so the whole thing should be surrounded by a ground as well ?
[19:31] <DanielRichman> it's good practice
[19:31] <Upu> on top and bottom layer ?
[19:31] <DanielRichman> yes, I think so
[19:32] <Upu> and in Eagle once you've autorouted is there anyway to remove them all ?
[19:32] <Upu> other than undo ?
[19:32] <natrium42> and then connect them with vias
[19:32] <DanielRichman> yeah there's the ripup tool
[19:32] <natrium42> (the ground layers)
[19:32] <DanielRichman> click it then click GO
[19:35] <Upu> where do I set the autorouter track width ?
[19:36] <natrium42> design rules
[19:36] <natrium42> or was it in net classes?
[19:36] <Upu> design rules
[19:38] <Upu> is it the layers 0.4mm ?
[19:38] <Upu> under design rules
[19:39] <DanielRichman> design rules iirc
[19:39] <DanielRichman> design rules -> sizes -> minimum width?
[19:40] <Upu> that's set to 10mil
[19:43] <Upu> I'll work it out
[19:48] <fsphil> tip-of-the-day: don't full-screen vnc to your own machine
[19:52] <natrium42> why not?
[19:56] <fsphil> things go very very weird
[19:56] <fsphil> I just got my mouse going again
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[20:29] <m1x10> goodnight all
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[21:20] <Laurenceb_> http://i.imgur.com/LFtgi.png
[21:20] <Laurenceb_> dongles ready :P just needs silkscreen
[21:20] <Laurenceb_> probably get it fabbed with v2 autopilot boards
[21:21] <johnnyfive|work> question: radio encoders take a digital signal and turn it into audio for a radio module to trasnmit?
[21:21] <Laurenceb_> depends on the hardware
[21:22] <Laurenceb_> they may just shift the Tx frequency
[21:23] <johnnyfive|work> I see. Well what do people usually use to convert their GPS info into a format that a radio module can transmit?
[21:23] <johnnyfive|work> I don't even know what that piece of hardware is called
[21:24] <Laurenceb_> microcontroller
[21:24] <johnnyfive|work> Eh, like an arduino? Using software? or what?
[21:39] <fsphil> yep, basically
[21:41] <johnnyfive|work> I see. Anyone here tried using a TinyTrak instead?
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[21:45] <fsphil> not sure, haven't heard of it being used
[21:49] <johnnyfive|work> Laurenceb_, fyi the term I was looking for was "Terminal Node Controller.
[21:49] <johnnyfive|work> "
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[22:04] <jcoxon> evening all
[22:10] <johnnyfive|work> evening!
[22:10] <jcoxon> hey johnnyfive
[22:10] <johnnyfive|work> how are ya
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[22:11] <jcoxon> good thanks
[22:11] <jcoxon> you?
[22:11] <johnnyfive|work> uh, well when i'm actively working on my balloon project I always feel like my head is in the clouds. So much to learn. But i'm good!
[22:11] <jcoxon> hehe
[22:11] <johnnyfive|work> Making breakthroughs today i think
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[22:11] <jcoxon> its quite a learning curve
[22:11] <jcoxon> but there is good info out there
[22:11] <johnnyfive|work> yea, esp when you don't have any knowledge on electronics at all
[22:12] <jcoxon> got to start somewhere
[22:12] <johnnyfive|work> yep yep! that's why i'm diving in
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[22:12] <johnnyfive|work> bound to make mistakes
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[22:18] <jcoxon> only way to learn
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[00:00] --- Thu Sep 23 2010