highaltitude.log.20090308

[00:00] <fergusnoble> yup, but not very well, if you try a launch from one location then when you try from another location the cache is cleared for the previous location
[00:00] <Laurenceb> ah yeah
[00:01] <fergusnoble> also the overlays are broken now, so just ignore them for now
[00:01] <Laurenceb> I was thinking of making a transatlantic sim
[00:01] <Laurenceb> to look at risk of condensation
[00:03] <gerard_> are you talking about CU Spaceflight sim?
[00:03] <Laurenceb> yes
[00:03] <fergusnoble> yeah, i am part of cu spaceflight
[00:03] <fergusnoble> gerard_: if you tell me your launch site coords i can add them to the list :)
[00:04] <gerard_> I used wyoming sim for my flight, and the prediction for ascent was followed very well, not for descent
[00:05] <gerard_> ok, my coords are: 41 29.74637 N,000 09.47810 W
[00:05] <gerard_> in decimal... hmm 1mom
[00:05] <hallam> the wyoming descent sim is.. simplistic
[00:06] <shellevil> fer: do you mean it needs to download all the data if you move the launch location by a few miles?
[00:06] <gerard_> 41.495773,-0.157968
[00:06] <fergusnoble> whats the name of the location?
[00:06] <gerard_> "Bujaraloz, Monegros"
[00:10] <fergusnoble> gerard_: done
[00:10] <gerard_> thanks
[00:11] <gerard_> will be useful for next flight :)
[00:11] <edmoore> everyone seems to be going crazy for orbital observatories atm
[00:12] <gerard_> your sim seems more useful than wyoming's one, since you can add more parameters
[00:12] <edmoore> that's why it was made!
[00:12] <edmoore> wyoming makes some assumptions which are quite limiting
[00:12] <gerard_> and they refused to open source it, so you were tied to just obtain a brief idea of your launch
[00:13] <fergusnoble> gerard_: i hope soon you will be able to overlay the wind speeds for different altitudes on the map
[00:13] <fergusnoble> if you have any ideas for features it would be good to hear them
[00:14] <gerard_> ok
[00:14] <gerard_> in which lang is it programmed? php?
[00:14] <fergusnoble> the simulation is in C and the interface is php
[00:14] <gerard_> ok
[00:15] <Laurenceb> php is nice :P
[00:15] <fergusnoble> the source code is available but its not pretty at all
[00:15] <Laurenceb> just been learning it over the past week
[00:15] <fergusnoble> Laurenceb: you really think so? i dont like it
[00:16] <gerard_> ok
[00:16] <Laurenceb> welll its not that nice as a language, but its easy to put together basic stuff
[00:16] <Laurenceb> nicer than asp
[00:16] <hallam> learning php means selling your soul in exchange for a license to print money
[00:16] <fergusnoble> true
[00:17] <gerard_> talking about sources, I have to make meteotek code look nice in some areas, then I'll publish it (soon)
[00:17] Nick change: hallam -> hallam|away
[00:17] <gerard_> I used php a few years ago to make a little blog, it's a good language and yes, better than asp
[00:18] <Laurenceb> tell you waht does suck, css
[00:18] <gerard_> what I have is javascript
[00:19] <fergusnoble> gerard_: you flew an SCP1000?
[00:19] <gerard_> things have changed a bit now, but hufff
[00:19] <gerard_> yes
[00:19] <fergusnoble> it would be interesting to know how well it worked at high altitude
[00:19] <gerard_> if you want registered data I can send you
[00:19] <edmoore> yes - data would be great - can see how it diverges compared to models
[00:20] <Laurenceb> we should have had one on the rocket
[00:20] <edmoore> fergusnoble and i can get a result on our bet about whether or not the errors increase linearly as pressure drops
[00:20] <fergusnoble> edmoore: hehe yup
[00:20] <edmoore> i guess if you plot it on a log-log sclae with a fat marker, it'll be linear
[00:20] <gerard_> let me post the graph
[00:21] <fergusnoble> gerard_: awesome, thanks
[00:21] <gerard_> 1mom
[00:22] <fergusnoble> edmoore: i think we have on on a sparkfun board we could hack onto the badger for the next flight
[00:22] <edmoore> grand
[00:26] <gerard_> http://teslabs.com/files/
[00:26] <gerard_> excel and openoffice files
[00:29] <fergusnoble> thanks
[00:48] <Laurenceb> http://blog.wired.com/wiredscience/2009/03/snakes.html
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[00:57] <edmoore> i distrust the model as much as i distrust the sensor at the kind of errors we're looking at
[00:57] <edmoore> not bad though at all
[00:59] <gerard_> talking about scp1000?
[00:59] <edmoore> the sensor is on the whole a lower pressure than the nasa model, and the differences broadly correlate with the three model-fits in the nasa model
[00:59] <Laurenceb> so it didnt saturate
[00:59] <edmoore> nope
[00:59] <Laurenceb> neat
[00:59] <Laurenceb> yeah really need some weather data
[01:00] <edmoore> at its biggest difference to the nasa model, at 25km, it is 1.4kBar different
[01:00] <Laurenceb> or a radio occultation sounding :P
[01:00] <edmoore> get on it!
[01:00] <hallam|away> which nasa model?
[01:00] Nick change: hallam|away -> hallam
[01:00] <hallam> did you correct for ground temperature?
[01:00] <Laurenceb> yeah that would be the first step
[01:00] <hallam> it makes a big difference, at least in planes
[01:02] <edmoore> sure sure, i don't have that data
[01:02] <Laurenceb> temp and humidity all the way up would enable you to find pressure pretty well
[01:03] <edmoore> on the ground there's about a 300 pascal difference
[01:03] <edmoore> but i don't know how to correct for gradient
[01:03] <Laurenceb> ok
[01:03] <edmoore> but basically, it looks like good data
[01:03] <Laurenceb> its an exponential decay
[01:03] <edmoore> it stays on!
[01:04] <edmoore> sure but the rates will be a function of temp/humidity surely?
[01:04] <Laurenceb> wow thats very good
[01:04] <Laurenceb> sorry, no not in the troposphere
[01:04] <Laurenceb> due to lapse rate
[01:04] <edmoore> yeah - basically piss all difference on the ground
[01:04] <Laurenceb> yeah you could treak the nasa model to give the right ground pressure and temp
[01:04] <Laurenceb> *tweak
[01:05] <edmoore> 3millibar
[01:05] <fergusnoble> edmoore: i make the biggest difference as 763Pa at an altitude of ~5km
[01:05] <edmoore> it would only tweak the intersect
[01:05] <Laurenceb> very nice
[01:05] <Laurenceb> yeah theres so many varibles
[01:05] <fergusnoble> and on the whole lower
[01:05] <edmoore> fergusnoble: i make it 1400 at 25km
[01:05] <edmoore> let me check i have my coefficints right
[01:05] <Laurenceb> well... tropopause height, lapse rate and ground temp and pressure
[01:06] <fergusnoble> i'll check too
[01:06] <Laurenceb> but at 30Km temp starts to rise again due to ozone layer :S
[01:06] <fergusnoble> but either way its an excellent fit
[01:06] <edmoore> agreed
[01:06] <Laurenceb> yeah it looks very impressive
[01:06] <Laurenceb> I'll have to order one
[01:07] <edmoore> yep, my numbers check out
[01:07] Action: shellevil wonders if capacitive a/d can measure pressure
[01:08] <shellevil> I suppose vacuum/air is too small
[01:09] <fergusnoble> edmoore: my coeffs are correct i think
[01:09] <edmoore> the turning points in the error curve definitely line up with the discrete plits in the modelling equations though - so basically am not concluding too much from the error readings.
[01:09] <edmoore> but as a totally 1st order approximation, the errors get bigger the lower the pressor
[01:09] <fergusnoble> yeah, thats error in the model not data
[01:10] <edmoore> error = difference, to be clear
[01:10] <Laurenceb> shellevil: should work
[01:10] <edmoore> fergusnoble: my coeffs are correct too
[01:10] <shellevil> Laurenceb: problem is mechanical stability I think
[01:10] <edmoore> and there's definitely the biggest difference at 25km in my carve
[01:10] <shellevil> Damn.
[01:11] <Laurenceb> shellevil: will be effected by humidity as well
[01:11] <edmoore> i see your 750ish one at 5km
[01:11] <edmoore> but it's not the biggest
[01:11] <shellevil> I should have characterised my RS80 pressure-transducers
[01:11] <fergusnoble> edmoore: interestingly for me the differences have a large spike at 5km, drop again, and then rise until apogee
[01:11] <fergusnoble> im sure ive made a mistake somewhere
[01:11] <shellevil> I could have offered one or two
[01:11] <Laurenceb> fergus: might be weather conditions
[01:11] <Laurenceb> and ozone layer
[01:11] <fergusnoble> Laurenceb: me and ed are supposedly using the same model against the same data
[01:12] <Laurenceb> lol nvm
[01:12] <Laurenceb> shellevil: its perfectly poss to get tons of res with AD7746
[01:12] <Laurenceb> just mechanical stability :/
[01:13] <fergusnoble> edmoore: check your email
[01:13] <Laurenceb> althoug... if you used it in differential mode....
[01:13] <edmoore> fergusnoble: to answer your question, you used excel :p
[01:14] <fergusnoble> well, i was just adding it to the existing spreadsheet
[01:14] <gerard_> I'll go to bed, thanks for your comments :) bye and see you!
[01:14] <fergusnoble> gerard_: bye
[01:14] <Laurenceb> shellevil: if you use some pcb tracks that had the same delta_cap due to thermal expansion and different effects from air it would work
[01:14] <Laurenceb> cya
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[01:16] <Laurenceb> something in the reigon of 20 bits air pressure res
[01:17] <shellevil> Laurenceb: I'd really want to try it though before coming out and stating it'll work
[01:18] <Laurenceb> yeah its a bit of a nutty idea
[01:18] <Laurenceb> but with an AD7746 would work on paper
[01:18] <shellevil> 1atm air is 1.00059
[01:18] <Laurenceb> then again the AD7746 only works on paper
[01:18] <shellevil> or 590ppm from vacuum
[01:18] <shellevil> fr4 is 4.7ish
[01:18] <Laurenceb> should be very easy to measure
[01:19] <Laurenceb> but thermal expansion will screw things up unless you compensate
[01:19] <shellevil> you'd want to bake the PCB first I think
[01:19] <shellevil> and conformal coat it too probably
[01:19] <Laurenceb> yeah
[01:20] <fergusnoble> edmoore: im off to bed
[01:20] <fergusnoble> let me know what you find
[01:20] <edmoore> ok, just spotted something
[01:20] <Laurenceb> the meaning of life
[01:20] <fergusnoble> edmoore: what?
[01:21] <edmoore> give me 2 mins just to double check
[01:25] <edmoore> something odd at my end with matlab handling a vector - gives the right result for single values but is being squiffy if input the entire vecotr
[01:26] <edmoore> you can probably go to be dlseeping easy
[01:26] <edmoore> bed sleeping*
[01:26] <fergusnoble> ok, goodnight
[01:26] <fergusnoble> excel scorn unwarranted
[01:26] <fergusnoble> :p
[01:27] <edmoore> it's always warrented!
[01:27] <hallam> g'night ferg
[01:27] <edmoore> picnic
[01:27] <edmoore> (problem in chair, not in computer)
[01:28] <hallam> pebkac
[01:28] <hallam> problem exists between keyboard and chair
[01:31] <hallam> fergusnoble: did you ever figure out what was going on with the crazyness on the DPO terminal? (whatever.py)
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[12:10] <jcoxon> afternoon all
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[12:44] <edmoore> morning all
[12:45] <edmoore> fergusnoble: are you up and atom?
[13:24] <fergusnoble> edmoore: hello
[13:24] <fergusnoble> yes, im up
[13:24] <edmoore> yo
[13:24] <edmoore> tess on phone
[13:24] <fergusnoble> ok
[13:35] <edmoore> so
[13:35] <edmoore> feeling ok this morn fergusnoble?
[13:35] <fergusnoble> not 100%
[13:35] <fergusnoble> but not too bad, same as yesterday i guess
[13:35] <fergusnoble> you?
[13:36] <edmoore> not bad - slept a lot
[13:37] <edmoore> feeling a little groggy now as a result
[13:38] <edmoore> fancy another sprint day or does the call of degree duty overcome?
[13:46] <edmoore> fergusnoble: ping
[13:46] <fergusnoble> pong
[13:47] <fergusnoble> edmoore: could do some, i need to do a bit of work but i can do that in parallel
[13:47] <edmoore> I love the school of thought that allows that :)
[13:59] <fergusnoble> so do want to do some work on the stuff?
[14:02] <edmoore> sorry, was writing a thankyou note
[14:02] <edmoore> yeah, sounds like it could be a useful thing to do
[14:02] <edmoore> can I just pitch up?
[14:08] <edmoore> fergusnoble: ping ping i promise. am attentive now :)
[14:09] <fergusnoble> sorry, i was distracted by the internets
[14:09] <fergusnoble> yeah sure, come over
[14:09] <edmoore> internets do that
[14:09] <edmoore> ok
[14:09] <edmoore> will be there in a bit
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[15:22] <Laurenceb> hello
[15:36] <edmoore> yo
[15:38] <Laurenceb> I've got mfsk working
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[16:43] <Laurenceb> its still a bit glitchy :-/
[16:46] <Laurenceb> I think it may be partly due to the filter on the radio board
[16:46] <Laurenceb> you need high tolerances
[16:46] <Laurenceb> +-1 or 2 % frequency deviation ideally
[16:48] <Laurenceb> or you risk ending up in the wrong frequency bin
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[17:31] <jcoxon> afternoon all
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[18:45] <Laurenceb> ello
[18:46] <jcoxon> hey Laurenceb
[18:47] <Laurenceb> I've got MFSK-64 working :P but its a bit glitchy
[18:47] <jcoxon> using steve's code?
[18:48] <Laurenceb> yeah
[18:48] <jcoxon> but upped to 64 rather then 16
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[18:48] <Laurenceb> yeah
[18:49] <Laurenceb> well 64 is just 62.5 baud
[18:49] <Laurenceb> still 16 tones
[18:49] <jcoxon> oh right
[18:49] <Laurenceb> its nice and fast but about 20% of packets are dodgy
[18:49] <Laurenceb> which isnt right
[18:50] <jcoxon> hmmmm
[18:50] <jcoxon> have you tried it directly from steve's code?
[18:50] <Laurenceb> no
[18:50] <jcoxon> that should generate wav files
[18:51] <Laurenceb> but I dont think its a glitch in the code
[18:51] <jcoxon> oh okay
[18:51] <Laurenceb> there interharmonic distortion in my soundcard and the filter on the radio is screwing it up a bit
[18:51] <Laurenceb> I'm going to change a few caps
[18:52] <jcoxon> your sound card is always causing issue
[18:52] <jcoxon> :-D
[18:52] <Laurenceb> its piss poor
[18:52] <Laurenceb> but fergusnoble has the same machine and gets it to work
[18:52] <jcoxon> weird
[18:53] <jcoxon> perhaps you should get a usb one or are they even worse?
[18:53] <Laurenceb> well 50 baud rtty is a bit easier
[18:53] <Laurenceb> yeah I might
[18:53] <natrium42> ello jcoxon & Laurenceb
[18:53] <jcoxon> hey natrium42
[18:53] <Laurenceb> tinky winky, dipsy, la la , po
[18:54] <natrium42> ...
[18:54] <natrium42> :P
[18:54] <natrium42> jcoxon, did you run any tests?
[18:55] <jcoxon> natrium42, i tried but it really need to get proper testing
[18:55] <jcoxon> testing -> tubing
[18:56] <jcoxon> i'm still a little worried its just a bit small
[18:57] <natrium42> k
[18:58] <jcoxon> one the silicone tubing arrives i'll rig up something
[18:58] Action: natrium42 desoldered MCU from the SPOT
[18:58] <natrium42> but it's not working yet :P
[18:58] <jcoxon> say we want to dump 1/3rd of our ballast how long do we want that to take?
[18:58] Action: jcoxon got his new gauge working
[18:59] <jcoxon> though he had to remove all the internals and is now using a micro servo to control the dial
[18:59] <natrium42> 1/3? few hours should be fine
[18:59] <Laurenceb> gauge?
[18:59] <Laurenceb> oh altitude?
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[19:01] <jcoxon> okay so actualy if its a fast drip then it should be fine
[19:04] <jcoxon> natrium42, steve is expecting the radio kit any day and is pretty much done sticking his mfsk code on a PIC
[19:05] <natrium42> good
[19:06] <jcoxon> what do you feel about cutdowns and such?
[19:07] <natrium42> i think they should be used for the 2nd mission, since we will have 2 way link
[19:07] <natrium42> but this first one, i am ok either way
[19:08] <jcoxon> yeah sounds good, first flight keeping it simple
[19:08] <mc-> jcoxon, tell steve I have a couple of rockmites, if he needs one
[19:09] <jcoxon> also less to fuss about while launch your first zp balloon
[19:09] <jcoxon> mc-, oh okay, he has a kit ordered but if that fails or they are really late i'll tell him
[19:09] <jcoxon> though he did say that its the simplest part of the job
[19:12] <natrium42> mc-, do you have a spot satellite messenger?
[19:12] <mc-> Hi natrium, I've got 4 modules
[19:13] <natrium42> whoa, really?
[19:13] <natrium42> http://www.natrium42.com/gallery2/v/balloon/transatlantic/spot-hacking-2c.jpg.html
[19:13] <natrium42> i desoldered the MCU
[19:13] <natrium42> and wired it up to my serial converter
[19:13] <natrium42> but it's not working yet
[19:13] <natrium42> maybe i missed one power line to the STX2 part
[19:14] <mc-> wow, that's a lot of work.
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[19:14] <mc-> I can send you the STX2 datasheet
[19:14] <natrium42> oh, i already got it
[19:14] <natrium42> i will PM you what i have found out
[19:14] <mc-> there one trick, you have to get the timing on CTS right for it to work.
[19:15] <mc-> and you need to calculate the checksum
[19:15] <natrium42> yeah, i know
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[19:15] <natrium42> well, RTS goes low, then STX2 lowers CTS within 20 ms
[19:15] <natrium42> i think a regular usb-to-serial converter should handle that fine
[19:15] <mc-> yes, I meant RTS timing needs to be correct
[19:15] <natrium42> or should i test with my own micro instead?
[19:16] <mc-> I got RS232 to work, but you need a button on RTS, and keep on repeating the message until you get the timing right on RTS
[19:17] <natrium42> hmm
[19:17] <natrium42> the micro on the spot seems to get it right every time
[19:17] <mc-> you know when the message went in, as it will reply on the TX line.
[19:17] <natrium42> did you get my PM? i sent you a few traces i made
[19:18] <mc-> yes, when a micro controls it, then the timing is correct
[19:20] <mc-> jcoxon, how is rocketboy using the rockmite to send MFSK?
[19:20] <mc-> sounds ingenious
[19:20] <jcoxon> i think hte rockmite has a variable cap or something
[19:21] <jcoxon> so he'll use the DAC to tap into that to make the 16 tones
[19:21] <jcoxon> (thats what i remember him mentioning at least)
[19:21] <natrium42> mc-, hmm, so perhaps i will connect it to micro instead
[19:21] <natrium42> i will upload a picture of current state
[19:22] <Laurenceb> STX2 is iridium IC ?
[19:22] <natrium42> globalstar simplex modem
[19:22] <Laurenceb> ok
[19:22] <Laurenceb> not bad
[19:26] <jcoxon> Laurenceb, hows the ballast sensor coming along?
[19:27] <mc-> natrium, I found it easiest to get it working by sending messages from a PC first, and then move to a micro
[19:28] <mc-> I can send you some PC basic code I used, will email.
[19:28] <Laurenceb> jcoxon: been working on mfsk
[19:28] <jcoxon> no worries
[19:28] <Laurenceb> guess I'll put together a test rig
[19:28] <Laurenceb> with an AVr instead of my usb/i2c device
[19:28] <jcoxon> that would be great - just watching teh time
[19:28] <Laurenceb> btw you can get I2C out of VGA
[19:29] <jcoxon> i know
[19:29] <jcoxon> depends on the graphic card driver
[19:30] <natrium42> mc-, http://www.natrium42.com/gallery2/v/balloon/transatlantic/spot-hacking-5c.jpg.html
[19:30] <natrium42> desoldered MCU and soldered RX,TX,RTS,CTS lines
[19:31] <Laurenceb> whats the mcu?
[19:31] <natrium42> MSP430
[19:31] <Laurenceb> ah
[19:38] <Laurenceb> canyou do a hex dump?
[19:40] <natrium42> tried, they blew the security fuse
[19:40] <natrium42> jtag is no good
[19:40] <natrium42> but i got most of the relevant schematic by tracing pins
[19:40] <natrium42> one sec, i will scan it in
[19:44] <Laurenceb> hmm http://www.sparkfun.com/commerce/product_info.php?products_id=7918
[19:45] <natrium42> http://www.natrium42.com/gallery2/v/balloon/transatlantic/spot-schematic.jpg.html
[19:46] <natrium42> i don't get those spot guys, they used 4 (!) ICs just to switch between two UARTs
[19:47] <natrium42> it's madness
[19:48] <hallam> crazy
[19:48] <hallam> so do you hope to be able to send arbitrary messages?
[19:48] <natrium42> yes
[19:49] <natrium42> http://natrium42.com/projects/spot.txt
[19:49] <natrium42> that's the format
[19:49] <natrium42> got 6 bytes to play with
[19:50] <Laurenceb> nice
[19:50] <Laurenceb> cool that it allows such short messages
[19:51] <natrium42> they are 9 bytes, actually
[19:51] <natrium42> but spot is really wasteful
[19:51] <natrium42> they had enough bits to send altitude data
[19:51] <mc-> actually it has a clever scheme to fit the lat/lon into 6 bytes
[19:52] <natrium42> mc-, scaling? :P
[19:52] <Laurenceb> srt of compressed float?
[19:52] <natrium42> DEGREES_PER_COUNT_LAT = 90.0 / 2^23
[19:52] <natrium42> decimal_latitude = encoded_latitude * DEGREES_PER_COUNT_LAT
[19:52] <natrium42> If result is greater than or equal to 90 degrees, 180 must be subtracted.
[19:53] <natrium42> similar for longitude
[19:53] <mc-> I managed to do a /90 in a PIC, which was difficult.
[19:54] <hallam> a divide by 90?
[19:54] <mc-> yes, you have to /90 and *2^23
[19:54] <mc-> ie the reverse of above
[19:55] <hallam> is this a pic16f84 or something?
[19:55] <mc-> 12C509
[19:55] <Laurenceb> why
[19:55] <Laurenceb> just get something nicer
[19:55] <hallam> ah
[19:56] <mc-> I have a PIC dev environment
[19:56] <hallam> I understand the allure of the 8 pin package
[19:56] <Laurenceb> avr uses gcc :P
[19:56] <Laurenceb> guess so
[19:56] <hallam> but seriously mc, if you haven't tried pic18 or dspic, really do
[19:56] <Laurenceb> or atmega :P
[19:57] <Laurenceb> or xmega
[19:57] <mc-> yeah, but I've never needed any processor power before.
[19:57] <hallam> even for simple stuff it saves a ton of development time to have C
[19:58] <mc-> I use C, and have a full emulator with single step etc
[19:58] <mc-> and can look at any variable
[19:58] <mc-> with breakpoints, code development is simple.
[20:00] <hallam> C that doesn't support division?
[20:01] <Laurenceb> natrium42: any idea on the datarate through globalstar?
[20:01] <mc-> I think it has division, but only with floating point on the bigger pics.
[20:01] <natrium42> Laurenceb, it's supposed to be faster than iridium
[20:01] <natrium42> but coverage area is smaller
[20:02] <natrium42> as global satellites cannot send data between themselves
[20:02] <Laurenceb> yeah
[20:02] <natrium42> they need contact to a ground station
[20:02] <mc-> natrium, can you get an iridium modem, or an orbcomm modem?
[20:02] <natrium42> i have an iridium phone
[20:02] <natrium42> but that's for 2nd flight :)
[20:03] <mc-> is it expensive to send data over iridium?
[20:04] <hallam> natrium42: how do you do the other end of the STx2 link? does it end up on SPOT's server or what?
[20:04] <natrium42> 500 minutes are about $650
[20:04] <natrium42> baudrate is ~2200 on average
[20:05] <hallam> do the minutes expire?
[20:05] <Laurenceb> I'm guessing it looks like a normal track?
[20:05] <natrium42> yes, mine are about to :(
[20:05] <Laurenceb> i.e. on their website
[20:05] <natrium42> but i will extend them (at a cost)
[20:05] <hallam> heh, so you encode your information in the lat/lon? nice
[20:05] <Laurenceb> natrium42: sao it uses 100mw for uplink?
[20:06] <natrium42> hallam, it goes through globalstar gateway and i guess there is some API for spot to use
[20:06] <natrium42> i can only access their tracker
[20:06] <natrium42> so don't get access to messages directly, only to lat/lon
[20:07] <hallam> I guess it does the job
[20:07] <hallam> hope the tracker doesn't get too confused
[20:07] <natrium42> :D
[20:07] <natrium42> it's damn simple to get the XML with last 50 locations
[20:08] <natrium42> tried it using curl
[20:09] <Laurenceb> where from?
[20:10] <natrium42> http://share.findmespot.com/shared/gogl.jsp?glId=0iYBQsZKupoOBTJq8x6cWA4PRJUYRi1ir
[20:10] <natrium42> that's for my spot
[20:10] <natrium42> if you look at the traffic between browser and server, you can get the protocol
[20:12] <natrium42> http://rafb.net/p/vyF1IT57.html
[20:12] <natrium42> that's the script
[20:12] <hallam> very cool
[20:13] <SpeedEvil> yup
[20:13] <hallam> so what telemetry will you be sending?
[20:13] <SpeedEvil> slowscan TV!
[20:13] <SpeedEvil> :)
[20:13] <natrium42> altitude, tank level, voltage
[20:13] <natrium42> maybe temperature
[20:13] <natrium42> lol, tv :D
[20:13] <natrium42> maybe 4 x 4 pixel TV :P
[20:14] <SpeedEvil> natrium42: have you considered one of those VGA pens?
[20:14] <natrium42> for local flight
[20:14] <hallam> you could send a half-decent jpeg for a minute of Iridium time
[20:14] <natrium42> hallam, yeah, flight 2
[20:15] <natrium42> going to share microsd between mcu and canon camera
[20:15] <natrium42> and use mcu to upload picture via iridium
[20:15] <SpeedEvil> analog switches?
[20:16] Action: natrium42 slaps SpeedEvil around a bit with a clue stick
[20:16] <hallam> see you guys later
[20:16] <SpeedEvil> Ah. Little servo unplugging it and plugging it into the other socket then.
[20:16] <SpeedEvil> wave.
[20:16] <natrium42> bye hallam
[20:16] <natrium42> lol SpeedEvil
[20:16] <natrium42> nah, mcu can control power to microsd and to camera
[20:17] <SpeedEvil> natrium42: I was meaning - might the canon have problems with power on the SD, when powered off
[20:17] <SpeedEvil> hence need isolating with analog switches
[20:17] <natrium42> doubt it, but we will see
[20:18] <natrium42> the VCC of microsd will not be connected to VCC of microsd slot of camera
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[20:21] <Laurenceb> can always use buffer ICs
[20:21] <Laurenceb> but its a cool technique to store jpegs on SD then read them with the MCU
[20:22] <Laurenceb> http://www.analog.com/en/other/analog-multipliersdividers/ad633/products/product.html
[20:22] <Laurenceb> ^ interesting
[20:28] <SpeedEvil> old multiplier is old.
[20:29] <Laurenceb> fun for experminenting with
[20:29] <SpeedEvil> Got a couple of samples of http://www.analog.com/en/other/analog-multipliersdividers/ADL5391/products/product.html
[20:29] <Laurenceb> I'm thinking of making my usb radio idea
[20:30] <SpeedEvil> package is admittedly more annoying
[20:30] <Laurenceb> neat
[20:30] <Laurenceb> but instead of on a usb stick, on a large 2 layer board
[20:30] <SpeedEvil> why?
[20:30] <Laurenceb> just to test the concept first
[20:30] <SpeedEvil> og
[20:31] <Laurenceb> easier to debug any issues
[20:31] <Laurenceb> before moving to 4 or maybe 6 or 8 layer usb stick
[20:32] <SpeedEvil> specs?
[20:33] <Laurenceb> hopefully DC to 1.5GHz
[20:33] <Laurenceb> but I'm not sure how feasible going down to DC is
[20:33] <SpeedEvil> Quite
[20:33] <Laurenceb> then ~30MHz bandwidth
[20:33] <SpeedEvil> you just turn off the mixer and stuff
[20:33] <Laurenceb> yeah
[20:34] <SpeedEvil> and feed input to A/D
[20:34] <Laurenceb> then you have to reroute signals?
[20:34] <SpeedEvil> Well - one analog switch is hardly much
[20:34] <SpeedEvil> assuming you have a seperate 'dc' input
[20:34] <Laurenceb> hmm guess it might work
[20:35] <Laurenceb> I hate making parts in eagle
[20:35] <SpeedEvil> It's all trivial.
[20:35] <Laurenceb> just have to click randomly until it works
[20:35] <SpeedEvil> Till you get to details like intermodulation measurements, and jam-resistance
[20:36] <SpeedEvil> then it gets horribly hard.
[20:36] <Laurenceb> well yeah its just a matter of how good the parts are
[20:36] <SpeedEvil> s/jam/adjacent strong channel/
[20:36] <SpeedEvil> well - and how good you are at putting them together
[20:36] <Laurenceb> its not too hard with a fairly large bosard
[20:36] <Laurenceb> just a few transmission lines
[20:36] <SpeedEvil> yeah
[20:37] <Laurenceb> with a usb stick it gets harder
[20:37] <Laurenceb> you will always have soime interference
[20:37] <mc-> natrium, I just pm'd you
[20:38] <shellevil> I've spent the day lifting floorboards
[20:38] <shellevil> so am now going to sleep for a bit
[20:43] <mc-> natrium42 ?
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[21:51] <Laurenceb> hmm atmega now goes down to 1.8v
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[22:10] <jatkins> hi all
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[23:36] <Laurenceb> hmm rebuilt the filter on the radio
[23:36] <Laurenceb> looks like it might be working better
[23:39] <Laurenceb> jcoxon_: did you copy wav files completely?
[23:39] <Laurenceb> no errors on the end or start?
[23:39] <Laurenceb> last two characters are screwed here
[23:42] <jcoxon_> Laurenceb, using fldigi i copied them fine
[23:42] <jcoxon_> though steve said he was having a few issues with truetty
[23:42] <jcoxon_> right night all
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[00:00] --- Mon Mar 9 2009