highaltitude.log.20060617

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[09:43] <jcoxon> morning all
[12:21] <Tiger^> :/
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[13:38] <Tiger^> hi, jcoxon.
[13:38] <jcoxon> hey Tiger^
[13:38] <Tiger^> what a mess :/
[13:38] <jcoxon> oh
[13:39] <Tiger^> everything worked and now i have all kinds of trouble
[13:40] <jcoxon> not good
[13:40] <Tiger^> yeah...
[13:40] <Tiger^> let alone the battery holders
[13:41] <Tiger^> i'll f*ing flood them with solder and hope they work
[13:41] <Tiger^> but the radio stopped working :/
[13:41] <jcoxon> uh oh
[13:41] <Tiger^> i couldn't get it to work with the j-pole
[13:42] <jcoxon> i've just started to interface my radio modems
[13:42] <Tiger^> so i build a simple dipole
[13:42] <Tiger^> it's really the simplest of antennas
[13:42] <Tiger^> same thing!
[13:45] <Tiger^> so i decied to go with the rubber ducky
[13:45] <Tiger^> decided*
[13:45] <Tiger^> 'cause i really don't have any more ideas
[13:46] <Tiger^> it worked with the ducky during all the tests
[13:46] <Tiger^> and now it doesn't :/
[13:46] <jcoxon> grr i know the feeling
[13:48] <Tiger^> yeah, and i've got three days :/
[13:48] <Tiger^> uh, more like two and a half
[13:48] <Tiger^> a new radio costs about $400-$500 :/
[13:48] <Tiger^> and i don't even now if that's it
[13:48] <jcoxon> just go back to basics
[13:48] <jcoxon> get the most important things fixed first
[13:49] <Tiger^> well apart from the batt holders and the radio everything works
[13:49] <Tiger^> the batt holders aren't that much of a problem
[13:49] <Tiger^> but without the radio launching seems without any sense...
[13:50] <jcoxon> true
[13:50] <jcoxon> but are they fixable?
[13:52] <Tiger^> the radio? i doubt it
[13:52] <Tiger^> i tried everything i could
[15:06] <Tiger^> ok... i think i solved it ;>
[15:06] <Tiger^> i hope so ;>
[15:17] <icez> jcoxon, discovery channel stole your project's name!:P
[15:32] <Tiger^> he should sue them
[15:32] <Tiger^> he'd be set up for life :P
[16:57] <jcoxon> hehe
[16:57] <jcoxon> not sure i can really claim the name
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[20:40] <jcoxon> hey all
[20:40] <jcoxon> got my radio modems working
[20:41] <jcoxon> :-D
[20:41] <icez> yay
[20:52] <jcoxon> suprisingly easy
[20:52] <jcoxon> very nearly finished
[20:54] <Tiger^> and i'll have to go with the phone :/
[20:55] <Tiger^> the radio's shot to hell.
[20:55] <Tiger^> i suspect a burnt final stage transistor
[20:55] <Tiger^> bummer
[20:55] <jcoxon> oh dear
[20:55] <jcoxon> well i'm a big fan of phone :-p
[20:55] <Tiger^> i'm not :P
[20:56] <Tiger^> i hate phones!
[20:56] <Tiger^> i want my radio!
[20:56] <Tiger^> now!
[20:56] <Tiger^> *cries*
[20:56] <Tiger^> ;)
[20:56] <Tiger^> the main problem with the phone is that you can't track the balloon
[20:57] <Tiger^> and with the radio, you can receive messages just before it falls to the ground
[20:57] <icez> unless you had a parrot that can use a phone
[20:57] <Tiger^> with the phone, you can just receive an sms when the balloon lands
[20:57] <jcoxon> Tiger^, tis true,
[20:58] <Tiger^> and if it crashlands... well.
[20:58] <jcoxon> it'll work
[20:58] <Tiger^> nevermind
[20:58] <jcoxon> don't worry
[20:58] <Tiger^> too late to do anything
[20:58] <jcoxon> i have faith in the phone
[20:58] <jcoxon> tried and tested
[20:58] <Tiger^> i could buy a new radio
[20:58] <Tiger^> $400... well.
[20:58] <jcoxon> thats alot
[20:58] <jcoxon> more then Peg III
[20:59] <jcoxon> actually thats a lie
[20:59] <Tiger^> yeah, it is.
[20:59] <jcoxon> the total value is about that
[21:01] <Tiger^> i'll leave the radio
[21:01] <Tiger^> it's good enough to send the carrier (as in carrier wave)
[21:01] <Tiger^> so at least i'll know it's alive
[21:03] <Tiger^> and it'll help to locate the balloon on the ground by radio direction finding
[21:05] <jcoxon> bbl
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[23:04] <jcoxon> :-)
[23:16] <Tiger^> it'll be a total failure :/
[23:16] <jcoxon> then abort
[23:16] <jcoxon> if it isn't worth the risk
[23:16] <jcoxon> if you're not happy with it don't do it
[23:16] <jcoxon> i learnt that the hard way
[23:18] <Tiger^> it'd be a second abort
[23:18] <Tiger^> first the car now this
[23:18] <Tiger^> i won't abort
[23:18] <jcoxon> but you'll still have a payload
[23:18] <Tiger^> and what's in the payload?
[23:18] <Tiger^> a $180 GPS
[23:18] <Tiger^> $60 worth of electronics
[23:19] <Tiger^> the box
[23:19] <Tiger^> and that's pretty much it
[23:19] <jcoxon> true
[23:19] <Tiger^> plus, i've already rented the helium..
[23:19] <Tiger^> i had to get to 5.6m tanks
[23:19] <Tiger^> they didn't have a 7m one
[23:19] <Tiger^> so i had to pay more
[23:19] <Tiger^> it'd be a waste of money not to launch
[23:19] <jcoxon> if it helps i'm using a phone
[23:20] <jcoxon> i trust them
[23:20] <Tiger^> yeah :)
[23:20] <Tiger^> i'm using a 6310 too
[23:20] <jcoxon> my radio modems are more of a test
[23:20] <jcoxon> i'm not relying on them especially as they have such a poor range
[23:20] <icez> rented, helium?
[23:20] <icez> *confused*
[23:20] <jcoxon> the tanks that is
[23:21] <icez> Tiger^, do you have pictures of your thing?
[23:21] <Tiger^> yeah, the tanks
[23:21] <Tiger^> icez: yeah, http://moo.pl/~tygrys/junk/bal
[23:22] <Tiger^> i have to take the pics of the final, umm, product :-)
[23:22] <Tiger^> jcoxon: did you see my telemetry software?
[23:22] <jcoxon> if i could find my camera cable i'd take some pictures
[23:22] <jcoxon> nop
[23:22] <jcoxon> e
[23:22] <Tiger^> jcoxon: http://moo.pl/~tygrys/junk/bal/29.html
[23:22] <Tiger^> jcoxon: http://moo.pl/~tygrys/junk/bal/30.html
[23:23] <icez> cool program though
[23:23] <icez> it's all sexy
[23:23] <jcoxon> oooo i have a question, as i'm now running my modem through the gumstix if i want to increase the battery life is it okay to have a secondary power supply in parallel?
[23:24] <Tiger^> icez: yeah, but now it turns out i'm not gonna use it :(
[23:24] <jcoxon> nice software by the way
[23:24] <Tiger^> thanks :)
[23:24] <jcoxon> next time Tiger^!!
[23:24] <Tiger^> yup
[23:24] <Tiger^> i'm already planning the new thing
[23:24] <icez> :D
[23:24] <Tiger^> in october
[23:24] <Tiger^> jcoxon: no it's not ok
[23:24] <jcoxon> like the helium filler
[23:24] <Tiger^> jcoxon: you will shorten the batt life.
[23:25] <jcoxon> hmmmm
[23:25] <jcoxon> why is that?
[23:26] <Tiger^> well
[23:27] <Tiger^> basically because connecting the batteries in parallel is for squeezing more power from them
[23:27] <Tiger^> so, let's say you can draw 2 amps without killing them instantly
[23:27] <Tiger^> when you connect two battery banks in parallel you can draw four amps
[23:27] <Tiger^> BUT
[23:28] <Tiger^> if one cell (i don't mean one battery - i mean one cell) will short internally
[23:28] <Tiger^> and believe me, that happens - sometimes you don't even notice it, you assume the batts just went dead
[23:28] <Tiger^> the good batteries will overpower the failed ones
[23:29] <Tiger^> and you'll have large currents all over the power supply wires
[23:29] <jcoxon> right, so how would i make it run longer?
[23:29] <Tiger^> so the other batts will die sooner
[23:30] <Tiger^> well... the best way is to make a good power supply.
[23:30] <jcoxon> i guess i could run the modem off its own supply
[23:30] <Tiger^> with a step-up/step-down regulator
[23:30] <jcoxon> i wonder what is on the gumstix itself
[23:30] <jcoxon> thats what is regulating the power
[23:30] <Tiger^> i doubt there's a step-up/down IC
[23:31] <jcoxon> i'm putting in 6v and it is then giving 3.3v to the modems through the serial port VCC pin
[23:31] <Tiger^> gumstix takes 6v?
[23:31] <jcoxon> yup
[23:32] <jcoxon> tis its limit
[23:32] <Tiger^> so it's got a step-down regulator
[23:32] <Tiger^> it takes 6v and makes a clean 5 out of it
[23:32] <jcoxon> you can give it between 4 and 6 i think
[23:32] <Tiger^> so maybe 3.3 :)
[23:33] <jcoxon> its between 3.6 and 6
[23:33] <Tiger^> the easiest thing you can do is take a step-up regulator
[23:34] <Tiger^> low drop, like an LM2940-T (the T is important, it's about operating temperature)
[23:34] <Tiger^> it makes 5V out of 5.25 - 12V
[23:34] <Tiger^> take six AA cells, so you'll have 9V
[23:35] <Tiger^> and you'll have 5V for the gumstix, even if the batteries discharge a bit
[23:35] <Tiger^> and a nice heater for the payload as a bonus :)
[23:35] <jcoxon> hmmm :-)
[23:35] <Tiger^> 'cause the thing gets hot, about 60 degrees C with 9V
[23:36] <Tiger^> well 50 maybe
[23:36] <Tiger^> not enough to melt anything
[23:36] <Tiger^> but enough to get a burn if you touch it
[23:36] <jcoxon> perhaps i should just give the modem its own power supply - that way if it fails then the gumstix will continue happily
[23:38] <Tiger^> yeah
[23:38] <Tiger^> and besides, RF gizmos shouldn't have a common supply rail with other electronics
[23:38] <jcoxon> right then
[23:38] <jcoxon> so a 3.3v regulator would be sensible
[23:39] <Tiger^> yeah, LM2940 has a sub-model for that, AFAIR.
[23:40] <Tiger^> uh, for the second balloon i'll won't buy any used shit from ebay
[23:40] <Tiger^> a new radio
[23:41] <Tiger^> two Kantronics TNCs
[23:41] <Tiger^> and a Gumstix or Soekris
[23:41] <Tiger^> i prefer the latter...
[23:41] <jcoxon> hehe
[23:41] <jcoxon> trying to start a flame war?
[23:41] <jcoxon> hehe
[23:41] <Tiger^> hehe
[23:41] <Tiger^> why didn't you use soekris?
[23:42] <jcoxon> (how about this?: http://www.acmesystems.it/?id=4)
[23:42] <jcoxon> nore really sure
[23:42] <jcoxon> not*
[23:43] <Tiger^> hmm
[23:43] <Tiger^> looks good
[23:43] <jcoxon> gumstixs are smaller
[23:43] <Tiger^> but i used Soekris
[23:43] <Tiger^> and i know it works ;)
[23:43] <jcoxon> go for what you know works!
[23:43] <Tiger^> well i know the gumstix works too
[23:43] <jcoxon> true
[23:43] <Tiger^> afterall it flew on pegasus :)
[23:43] <jcoxon> true
[23:44] <jcoxon> hehe
[23:44] <Tiger^> and even worked once!
[23:44] <jcoxon> what sort of prices are soekris
[23:44] <jcoxon> haha
[23:44] <Tiger^> *evil girn*
[23:44] <Tiger^> grin*
[23:44] <Tiger^> hmm let's see
[23:44] <jcoxon> it'll work this time as well! :-D
[23:45] <Tiger^> based on an up to 266 Mhz 586 class processor. It has three 10/100 Mbit ethernet ports, up to 256 Mbyte SDRAM main memory and uses a CompactFlash module for program and data storage. It can be expanded using a MiniPCI type III board and a low-power standard PCI board.
[23:45] <icez> 130-700$
[23:45] <icez> :/
[23:45] <Tiger^> net4801-50 Board only
[23:45] <Tiger^> $213
[23:45] <jcoxon> oh right
[23:45] <Tiger^> and the gumstix?
[23:46] <jcoxon> which regulator should i get? (sorry for all the electronics questions - i'm rubbish at it!): http://www.maplin.co.uk/search.aspx?MenuNo=463&MenuName=Voltage%20Regulators&FromMenu=y&DOY=17m6
[23:46] <jcoxon> well a waysmall 200 is $129
[23:46] <jcoxon> thats what i use for peg I
[23:47] <Tiger^> oh ok
[23:47] <jcoxon> i now have a connex 200 with a gpstix
[23:47] <jcoxon> which is about $230
[23:47] <Tiger^> they don't have the lm2940, only lm2940ct
[23:47] <Tiger^> which is not guaranteed to work below 0 C
[23:48] <jcoxon> it is smaller and lighter and i reckon consumes less power
[23:49] <jcoxon> with the lm2940ct it outputs 5v
[23:49] <jcoxon> i really only want 3.3b
[23:49] <jcoxon> 3.3v*
[23:50] <Tiger^> 2940-CT-5 outputs 5V, to be exact
[23:50] <Tiger^> hmm yeah, there's no 3.3V version
[23:50] <Tiger^> let's see
[23:53] <Tiger^> jcoxon: how much current do you need?
[23:54] <Tiger^> take a look at the radiomodem's rating
[23:54] <jcoxon> will do
[23:54] <jcoxon> one sec
[23:55] <jcoxon> at 100% TX it will be 240mA
[23:55] <jcoxon> thats the most
[23:56] <jcoxon> at 10%TX its 54mA which is more realistic as it only sending gps data every 5 seconds
[23:57] <jcoxon> it does say that pin 10 can take between 3.3V and 5.5V with +50mV ripple
[23:57] <jcoxon> so perhaps a 5v regulator would be suitable
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[23:58] <Tiger^> if you want 3.3V, you should use: LM1117T-3.3
[23:58] <Tiger^> http://www.national.com/pf/LM/LM1117.html
[23:58] <Tiger^> 800mA max
[23:59] <jcoxon> ooo maplin sell those
[23:59] <jcoxon> i could get some tomorrow then (maplin is the only local electronics shop)
[00:00] <Tiger^> great, just watch out for operating temperature
[00:00] --- Sun Jun 18 2006