IRC log for #qi-hardware on 20150614

01:55.43*** join/#qi-hardware sb0 (~lekernel@173-160-41-85-colorado.hfc.comcastbusiness.net)
01:56.27*** join/#qi-hardware Haswell (~broaderba@unaffiliated/haswell)
03:38.59*** join/#qi-hardware Textmode (~boneidle@adsl-1-au-2-174.ozonline.com.au)
08:40.33*** join/#qi-hardware dos1 (~dos1@unaffiliated/dos1)
11:06.23*** join/#qi-hardware jwhitmore (~jwhitmore@host217-43-211-30.range217-43.btcentralplus.com)
11:27.17*** join/#qi-hardware arossdotme (~zxy@79-69-198-164.dynamic.dsl.as9105.com)
11:28.53*** join/#qi-hardware jwhitmore (~jwhitmore@host81-153-239-218.range81-153.btcentralplus.com)
11:46.55*** join/#qi-hardware jwhitmore (~jwhitmore@host86-154-191-125.range86-154.btcentralplus.com)
12:08.53*** join/#qi-hardware archang (~archang@111.198.29.53)
12:14.52*** join/#qi-hardware jwhitmore (~jwhitmore@host217-43-211-1.range217-43.btcentralplus.com)
12:41.47*** join/#qi-hardware jwhitmore (~jwhitmore@host213-122-244-177.range213-122.btcentralplus.com)
13:21.26*** join/#qi-hardware pcercuei (~pcercuei@95.91.238.39)
14:09.34*** join/#qi-hardware jwhitmore (~jwhitmore@host213-122-244-177.range213-122.btcentralplus.com)
14:11.52DocScrutinizer05interesting module/EVB: http://www.globalstar.com/shop/index.php?main_page=product_info&cPath=23&products_id=81
14:12.37whitequarkooh neat
14:13.07eintopfthe question is, can you put it into the neo900?
14:13.21eintopfand the other question is, will it blend?
14:13.35eintopf:-)
14:22.01DocScrutinizer05http://www.globalstar.com/shop/index.php?main_page=product_info&cPath=22&products_id=108
14:22.12DocScrutinizer05simplex upstream
14:22.47wpwrakstandby 0.5 W typical. oh dear !
14:27.32DocScrutinizer05yep, of course
14:28.03DocScrutinizer05you hardly can find much better for sat communications
14:28.32DocScrutinizer05well, their phones are allegedly 2 days standby
14:29.37DocScrutinizer05but then I wonder what "standby" means for a device that requires unfolding and extending the antenna before it can enter active mode
14:30.16DocScrutinizer05generally sat phones are not really meant to _receive_ calls
14:30.31wpwrakbtw, philae is back ! (article in german) http://www.heise.de/newsticker/meldung/Hallo-vom-Kometen-Lander-Philae-meldet-sich-zurueck-2690194.html
14:30.46DocScrutinizer05HAH!
14:32.15whitequarkI wonder if the .5W are for something like TCXO
14:36.38DocScrutinizer05hmm, I don't think they are that pciky about their clock frequency
14:37.14DocScrutinizer05it's rather simply continuous mode RX, not optimized by any sleep modes or similar
14:38.28DocScrutinizer05idly wonders what been GTA02/calypso power rating when applying sleep=0 #1024 bug work around
14:41.00DocScrutinizer05https://totalueberwachung.de/blog/category/openmoko
14:45.28DocScrutinizer05so you could guess like: battery capacity ~4Wh, 6-8h of standby without proper deep-sleep => 0.5W
14:46.12DocScrutinizer05no need for a crystal heating to burn power ;-)
14:46.47eintopfI remember my old smartphone, when I did to turn on the GPS it was extremely hot
14:47.06eintopfand my current smartphone, when it's hot _or_ cold then touchscreen doesn't work
14:47.21DocScrutinizer05wl1251 wlan chipset in AP scan mode (which forbids any powersaving (aka deepsleep) mode) also is known to be a terrible power hog
14:47.41eintopfI think, I need a neo900
14:48.15DocScrutinizer05hurry, we might have no more available for preorder at end of month ;-)
14:49.16eintopf:O
14:49.29DocScrutinizer05kidding aside, we might want to start N900 sourcing next month, and it's highly questionable if we could source further N900 for late customers
14:50.50DocScrutinizer05when you only want a NeoN board to upgrade your own N900, don't worry
14:51.03eintopfI don't have a N900
14:51.03DocScrutinizer05then your deadline is more relaxed
14:51.10eintopfI have a motorola milestone
14:51.29eintopfand now one without a keyboard and I want my keyboard back
14:51.49eintopf480 eur is a little bit too expensive for me :/
14:52.09DocScrutinizer05that's even only a down payment
14:52.19eintopfthen wpwrak will kill me, I should buy a frequency spectrum analyzer for that money
14:52.42DocScrutinizer05o.O spectrum analyzer? what for?
14:53.02eintopf802.15.4 stuff
14:53.07DocScrutinizer05hmmmm
14:53.53DocScrutinizer05I doubt *I* could properly use a spectrum analyzer for such stuff
14:54.15DocScrutinizer05also isn't that 2.4GHz?
14:54.42wpwrakyup, 2.4 GHz
14:54.43DocScrutinizer05I wonder where you get which spectrum analyzer for 480 bucks that can do 2.4GHz
14:55.01DocScrutinizer05and provide useful readouts
14:55.24DocScrutinizer05get a RTL2032 ;-)
14:55.30DocScrutinizer0515bucks
14:55.38eintopfhttp://www.aaronia.com/products/spectrum-analyzers/HF-2025E-V3-Low-Cost-Spectrum-Analyzer/
14:55.39whitequarkcan't you lower it from 2.4GHz to some IF and then use something with a few tens of MHz of bandwidth?
14:55.43eintopfthat's what wpwrak told me
14:55.48wpwraka wee bit more expensive: http://www.aaronia.com/products/spectrum-analyzers/HF-2025E-V3-Low-Cost-Spectrum-Analyzer/
14:55.52DocScrutinizer05prolly just as good for the purpose you faintly mentioned
14:56.00wpwrakheh :)
14:57.07eintopfI google RTL2032 and got results for a stick which helps me to put my clothes on
14:58.02DocScrutinizer05oops 2832 sorry
14:58.08DocScrutinizer05http://hdsdr.de/RTLSDR_with_HDSDR.pdf
14:59.05DocScrutinizer05https://www.adafruit.com/products/1497
14:59.47DocScrutinizer05mmmph, 1850MHz
14:59.48eintopfmhh, if this device can do 2.4 Ghz spectrum of 802.15.4 then I could put a firmware on which implements 802.15.4 standard and using it as a transceiver?
15:00.06eintopfor is the modulation differs, or that doesn't matter?
15:00.07DocScrutinizer05it's RX only
15:00.14eintopfah
15:00.24DocScrutinizer05but it has no demodulator, it's a SDR
15:00.25*** join/#qi-hardware _whitelogger (whitelogge@fehu.whitequark.org)
15:00.25*** mode/#qi-hardware [+v _whitelogger] by ChanServ
15:00.49DocScrutinizer05it provides I/Q digital data via USB
15:01.12eintopfI thought I could make atusb2
15:01.16eintopfwith open firmware
15:01.24eintopfand atusb protocol ;-)
15:01.34DocScrutinizer05I *guess* you could use a cheap analog sat receiver for forntend as well
15:02.45eintopfyou want to tell me now, that when I have some LNB and an analog receiver and I set the frequency to the right. Then I can see some patterns in the "analog snow screen" ?
15:02.59eintopffrom my 802.15.4 transceiver
15:03.05eintopfI do some transmitting then
15:03.17eintopfcan't believe that
15:04.58eintopfso analog tv is about  950−2150 MHz
15:05.06eintopf950 - 2150
15:05.23DocScrutinizer05http://sdr.osmocom.org/trac/wiki/rtl-sdr
15:05.31eintopfand my transceivers are 2405 - 2480
15:09.15DocScrutinizer05http://www.rtl-sdr.com/
15:09.41DocScrutinizer05yes, I already noticed it's a 300MHz off
15:19.50DocScrutinizer05awesome: https://www.youtube.com/watch?v=-k2ZuhAz0ac
15:51.56*** join/#qi-hardware bzb (~bzb@198-48-196-219.cpe.pppoe.ca)
15:52.27DocScrutinizer05eintopf: yep, analog sat receivers have a IF of 950−2150 MHz
15:53.30eintopfok
15:53.52DocScrutinizer05anyway I wonder why you need a spectrum analyzer for those 802.15.4
15:54.49eintopfdetermine xtal trims, I am not an expert. But the xtal pins of the transceiver has the feature to set the pin capacity
15:55.44eintopfthey doing PLL and then I can set these capacity pins to the right value, when I see the result
15:56.10eintopfthat's I think how it works, this is what wpwrak teach me :/
15:59.30DocScrutinizer05you need a frequency counter for this, or a very precise receiver, not a spectrum analyser
16:00.27eintopfbut when I see the spectrum I can see the piek
16:00.48eintopfand the piek should be something like the frequency and around is some gauss curve
16:01.14DocScrutinizer05huh? no, it should not have any gauss curve
16:01.15eintopfa gauss curve and a piek in the frequeceny which is set
16:01.23eintopfmhh
16:01.39eintopfthen only a piek in the middle where the frequency is set the rest is random
16:01.49DocScrutinizer05a gauss curve or the like would be seen by modulated signals
16:02.01eintopfit's modulated
16:02.05DocScrutinizer05which create sideband frequencies
16:02.10eintopfQPSK or something
16:02.18DocScrutinizer05the xtal frequency is NOT modulated
16:02.53eintopfyea, but I cannot touch the pins inside the transceiver
16:03.11eintopfthen I need to listen to the frequency and the real result
16:05.27DocScrutinizer05even then you're simply not interested in that gauss curve, any arbitrary frequency counter will already pick up the "peek" for you
16:06.07DocScrutinizer05you say you need a spectrum analyzer to show the sidebands so you can ignore them, that's a tad awkward approach
16:06.36eintopfThen I could use maybe a atmega32 and use it as frequency counter
16:06.52DocScrutinizer05for 2.4GHz hardly
16:07.07eintopfit's PLL
16:07.17eintopfthere is some 16 Mhz crystal
16:07.28eintopfcan I not check this frequency?
16:07.36DocScrutinizer05but you should be able to touch one of the two XTAL pins of the chip with a high impedance probe
16:08.00DocScrutinizer05or even couple inductively to the RF emission of the xtal
16:08.29DocScrutinizer05the XTAL1/2 pins are output and input basically
16:09.10DocScrutinizer05you probably can touch the output without detuning the xtal oscillator too much, when you use e.g. a 10MOhm scope probe
16:10.15DocScrutinizer05but honestly why do you worry that much about exact tuning? just tune your one receiver so it works fine with the peer transmitter, so both use same (possibly not totally correct) frequency
16:11.22DocScrutinizer05you only worry about absolute correct frequency when building a 1000 or a million devices and all should be inter-operable with each other
16:11.40DocScrutinizer05and possibly even to 2nd source devices not built by you
16:12.06DocScrutinizer05or you worry when you need to pass approvals my FCC and the likes
16:12.19DocScrutinizer05s/my/by/
16:12.19qi-botDocScrutinizer05 meant: "or you worry when you need to pass approvals by FCC and the likes"
16:15.42DocScrutinizer05sorry when I'm assuming (e.g. existence of external xtal and XTAL1(2 pins on chip) and your situation looks different. I have no info what you actually do and what's your circuit
16:16.34DocScrutinizer05but generally for adjusting frequency you don't use a spectrum analyzer
16:16.48DocScrutinizer05you may, when you already have one
16:17.04DocScrutinizer05and when the one you have is calibrated and pretty exact
16:18.54DocScrutinizer05for your average dirt cheap spectrum analyzer (500 bucks) odds are your own DIY circuit is more precisely tuned to the target frequency than the SA's internal reference clock
16:21.00DocScrutinizer05take a shortwafe radio, tune it to 16MHz and see if you can pick up the XTAL signal
16:24.14DocScrutinizer05if you're lucky you may create interference with a nearby (in freq) broadcast station, and form the pitch/freq of resulting beat product tone you can know the difference in freq between your xtal signal and the broadcast station. Then you just need to find out which broadcast station this is you hear, and you easily can find their exact frequency they transmit on, which is pretty precise
16:29.39DocScrutinizer05whatever the chip you use, when it has a xtal oscillator then it also provides a means to tune that, by either providing the 16MHz to a test pin so you could run whatever freq counter you like on it (use a 1/16E6 divider and compare the number of seconds counted in one hour against an arbitrary watch), or the chip has built in freq offset evaluation and all it needs is a correct freq external 2.4MHz signal and the chip tells you in
16:29.41DocScrutinizer05some diagnostic register how much the internal xtal is offset from the applied external reference signal
16:32.02DocScrutinizer05and for a last resort you can attach to the crystal mechanically/acoustically, using e.g. a piezo. This shouldn't detune your xtal oscillator frequency and will even work for (never seen yet) chips with integrated crystal
16:33.50DocScrutinizer05while on this topic: a generally unknown/neglected issue is mechanical-acoustical coupling and interference between different crystals SMT-mounted to same PCB
16:35.41DocScrutinizer05crystals would make for nice hidden/stealth microphones in an exploited circuit :-)
16:38.16DocScrutinizer05should find out if the crystal's frequency (or at least phase) also gets detuned/modulated from the acceleration by audible frequency mechano-acoustic waves introduced to the PCB
16:38.17whitequarkoh, cool idea
16:38.27whitequarkyou know tantalum caps are piezoelectric, right?
16:38.38whitequarkthat also works
16:38.42DocScrutinizer05err, not known of tantalum, no
16:38.49DocScrutinizer05X5R yes
16:39.01whitequarker, yes, ceramic of course
16:39.04whitequarkbrain fart
16:39.22DocScrutinizer05wouldn't feel surprised to see similar effects in generic electrolytic caps though
16:40.04DocScrutinizer05particularly when they are already a tad aged and dried, so some gas is inside between the electrodes
16:40.55DocScrutinizer05for gas-free electrolyte I dunno if we could expect much sensitivity to pressure / mechanical interference
16:44.37DocScrutinizer05(phase modulation of reference clock)  wouldn't be any threat in a PLL design, since the PLL has LPFs that filter this out completely
16:55.31DocScrutinizer05(never seen yet) sorry, incorrect. The legendary DALLAS chip must have had an integrated crystal iirc
16:56.54DocScrutinizer05http://www.rotteneggs.com/site/stories/7c4efb20-9ca7-11e0-8585-cda61f05aee7/dallas_chip_battery_hack/
17:01.37*** join/#qi-hardware sb0 (~lekernel@173-160-41-85-colorado.hfc.comcastbusiness.net)
19:45.34*** join/#qi-hardware wej (~j@2001:1af8:4010:a08c:1::6e)
20:40.11*** join/#qi-hardware apelete (~apelete@176-26-190-109.dsl.ovh.fr)
22:22.18*** join/#qi-hardware Haswell (~broaderba@unaffiliated/haswell)

Generated by irclog2html.pl Modified by Tim Riker to work with infobot.