IRC log for #neo900 on 20140914

00:38.35*** join/#neo900 infobot (ibot@rikers.org)
00:38.35*** topic/#neo900 is http://neo900.org | conversations are logged to http://infobot.rikers.org/%23neo900/ | 2013-11-04 - the day our fundraiser reached its goal, 25k EUR | 2013-12-02 - 200 devices reached! | 12-14 50035EUR, 232 units | 01-17 60kEUR, 300 units | 02-28 333 units, 70k€ | 03-28 350 units, 400 donations, 73555€ | 0501 360 410 75k | 0712 183 ~30k | 0810 300 ~49k | 0914 346 ~56k
00:38.35*** mode/#neo900 [+v infobot] by ChanServ
00:38.40DocScrutinizer05~wb
00:38.40infobotIt's great to be back!
01:22.33wpwrakhmm. looking at the RF side of GPS, some doubts becreep me. what we have is the modem powering the LNA (VGNSS) and the CPU watching that signal and detecting any wrongfulness
01:23.31wpwrakwith the addition of the GPS kill switch, that one gets controlled by the same net as well
01:24.43wpwrakso gps kill is under the control of the modem, though the CPU can see if anything untoward happens there
01:26.52wpwrakwe could give the CPU more authority, though: since we use VGNSS for control only, not for power, we could add a series resistor on the modem side, allowing the CPU to command an a shutdown the modem can't veto
01:27.38DocScrutinizer05that's a interim design
01:27.56DocScrutinizer05the final design is meant to be exactly what you sketched
01:28.39DocScrutinizer05or even use a gate instead of a resistor
01:28.41wpwrakan even more paranoid choice would be to have two lines: one on the kill/lna side (to command a shutdown) and the other on the modem side (to see if the modem attempts to do anything, even if we've already prevented it from succeeding)
01:28.53DocScrutinizer05yep, exactly
01:29.10wpwrakso, 2 signals ?
01:29.23DocScrutinizer05prolly, when we're not short on GPIO
01:29.44DocScrutinizer05(btw same applies to SIM-VDD)
01:30.04DocScrutinizer05and there even RFID goes in between as well
01:30.30wpwrakRFID = ?
01:31.01DocScrutinizer05NFC, http://www.ic-on-line.cn/download.php?id=1698663&pdfid=95F70B32A8CE7F4EDBE287FEA56A3511&file=0350%5Cpn544_2767746.pdf
01:31.16wpwrakSIM-VDD: switch _and_ sense ? or just sense ?
01:31.43wpwrakbut we dom't have NFC ?
01:33.05DocScrutinizer059.3Supply of a secure element
01:33.07DocScrutinizer05PN544 provides integrated PMU to ensure supply voltage for both secure elements
01:33.08DocScrutinizer05connected via SWP or NFC WI interface.
01:33.10DocScrutinizer059.3.1Supply of SIM with SWP interface
01:33.29DocScrutinizer05we're supposed to have NFC, if any possible
01:33.38wpwrakoh dear ...
01:33.42DocScrutinizer05yeah
01:34.20wpwrakwhat other surprises do you have in store ? it seems that every time we approach a point where the design seems to settle, you pull a new rabbit out of your hat :-(
01:34.42DocScrutinizer05we might get problems with the antenna, so I like to think of antenna as a user-retrofit-option
01:34.58wpwrakproject sisyphus ...
01:35.15DocScrutinizer05sorry
01:37.03DocScrutinizer05http://projects.goldelico.com/p/neo900/issues/546/  http://projects.goldelico.com/p/neo900/issues/539/
01:39.50wpwrakso the PN532 goes into the design as well ?
01:41.54wpwrakkewl, has an 8051 :)
01:42.33DocScrutinizer05hehe, good you love it
01:43.22DocScrutinizer05please see the 539 ticket. It's still unclear what Nik supports to go in there
01:43.44wpwrakis that v2 item ?
01:44.05DocScrutinizer05Harald recommended PN532 iirc (been almost a year since I chatted with him about which chip to get)
01:44.43wpwrak"chip cost (1Q and 1kQ)" as if anyone ever bought chips at 1Q ;-) well, maybe some house-prices FPGA
01:44.57DocScrutinizer05(v2 item) not mandatorily, since we have no CPU and no final antenna design, and even hackerbus isn't specified yet
01:46.10wpwrakas i understand nik, he wants to stabilize the component placement on LOWER. so if NFC is a LOWER item, we should at least mention it
01:46.29DocScrutinizer05I left it out from discussion so far since it's not THAT importaant in V2 yet, and we maybe first want to see how stuff looks like when we got all the mandatory subsystems, before we try to cram in stuff that's unclear if it even works
01:46.43DocScrutinizer05good point, indeed
01:47.34DocScrutinizer05assuming we use my suggestion how to impleent uSD-daugtherboard and hackerbus, it would likely go to UPPEr though
01:48.59DocScrutinizer05and from UPPER straight to the two antenna pads next to uSD on daughterboard, via a B2B conn passing through a hole in LOWER
01:49.40wpwrakB2B RF ? urgh
01:49.55DocScrutinizer05meh, that's not "RF"
01:50.04DocScrutinizer05that's a cheesy 14MHz
01:50.09wpwrak;-)
01:50.38wpwrakso you'd just route it unshieldedly along the digital signals ?
01:51.38DocScrutinizer05of course not
01:51.54wpwrakelse, you need to match a regular b2b connector with some shielded critter, for which i wish thee luck ;-) (remember the usb board disaster of milkymist ? well, i think they've been clumsy there, but still ...)
01:52.15DocScrutinizer05a) it's balanced iirc, b) you of course need a GND between it and the digital signals
01:52.35wpwrakokay, but the same unshielded connector ?
01:52.56DocScrutinizer05completely unspecified so far
01:53.21DocScrutinizer05at end of this connector, it diectly enters the antenna anyway
01:53.51DocScrutinizer05so a 5mm more of "antenna" won't hurt that much, eh?
01:54.04wpwrakyou said the antenna may be a customer option anyway, so perhaps we could just have a connector at UPPER/LOWER and leave it at that ?
01:54.28DocScrutinizer05please elaborate
01:54.45wpwrak"we might get problems with the antenna, so I like to think of antenna as a user-retrofit-option"
01:55.08DocScrutinizer05I know what I wrote
01:55.19wpwrakso why not let the user connect to where the signal originates ?
01:55.46DocScrutinizer05because that would be somewhere on the PCB wher nobody can reach it
01:56.28wpwrakalright, at the edge of the pcb where the signal originates ?
01:56.42DocScrutinizer05how's that any difference?
01:57.13DocScrutinizer05the edge of the PCB is civered by the case (or the spacer frame, for UPPER)
01:57.19DocScrutinizer05coverd
01:58.00DocScrutinizer05alternatively I considered having it on the N900 battery bay testpoint area
01:58.46DocScrutinizer05but that would make it pretty hard to come up with a feasible and somethat decent solution how to connect an antenna there
01:58.59wpwrakis anything antenna-sized that attaches to them safe when the board is removed from the bottom shell ?
01:59.21DocScrutinizer05sorry, please rephrase
01:59.45wpwraki mean: if the antenna attaches there, would it be at risk of breaking off when disassembling the device ?
01:59.56DocScrutinizer05where?
02:00.03wpwrakin the battery bay
02:00.18DocScrutinizer05it would be at risk of breaking when somebody changes the battery
02:00.42wpwrakthat doesn't sound nice
02:01.13wpwrakthat is, unless we call it the iNeo900. then it's cool ;-)
02:01.56DocScrutinizer05I think http://projects.goldelico.com/p/neo900/issues/539/#ic1561 is to the point
02:01.58wpwrakconnectivity to the CPU would be I2C, i assume ?
02:03.41wpwrak(ant on lid) yeah, if there's enough vertical space that sounds reasonable. kinda like nokia connect to the antennas, too. just that they have [access to] simpler contacts.
02:03.45DocScrutinizer05I2C if no conflicts, which I'd not expect. Otherwise we could use SPI or UART
02:04.35wpwrak"which I'd not expect" = you expect conflicts ?
02:04.57DocScrutinizer05no, I expect not to see any conflicts
02:05.35wpwrakgood. neither do i. with to may buses to choose from :)
02:08.54DocScrutinizer05another reason why I didn't mention NFC yet: we *might* provide the needed signals on hackerbus and place the PN544 on the flexPCB together with the antenna
02:08.54wpwrakany other major subsystem that's not in the block diagram ?
02:09.30DocScrutinizer05right now I'm not aware of any that we would need in V2
02:09.55wpwrakand for v3 ?
02:12.26DocScrutinizer05well, CPU, RAM, eMMC...
02:12.43wpwrakthat's already in the block diagram :)
02:13.04DocScrutinizer05I haven't checked the blocj diagram versus V3
02:14.17DocScrutinizer05I'm not going to make a legally binding statement here and now. It's sunday morning 4AM
02:15.12wpwraksure, take your time. but i think we better make sure the major things that shall be present in the end are on the table (= in the block diagram) at v2
02:17.16DocScrutinizer05check N900 schematics, GTA02A schematics and TRM, http://projects.goldelico.com/p/neo900/issues/ and neo900 feasibility study and particularly http://neo900.org/specs
02:18.49wpwraki did all that already. but for example i thought nfc had been dropped.
02:19.42wpwrakand there are also things i never saw coming, like the complex IR subsystem. so it's really you who has to tell me what's missing
02:21.42DocScrutinizer05complex IR?
02:22.18DocScrutinizer05it seems to me we have a total BOM of less than 2 dozen components for IR
02:22.37wpwrakbtw, the specs have an "Ambient light" sensor. is that also missing ?
02:23.12DocScrutinizer05err, we had it at one time
02:23.40DocScrutinizer05on your block diagram it's definitely not missing since it's in display half
02:23.50DocScrutinizer05good night!
02:24.14wpwrakaah, an N900 component. nice ;)
02:58.46wpwrakhmm. newark.com are down ... but they do have a pretty error page
03:08.20DocScrutinizer05sth is buggy today
03:09.54DocScrutinizer05dos1's internet down, freenode IRC got hacked, freenode webserver been down, now newark (whatever that is)
03:10.23DocScrutinizer05and funny enough just the warning LED of my home automation lits up
03:10.26wpwraknewark.com is the US side of farnell (element14)
03:10.40*** join/#neo900 Kabouik__ (~quassel@252.133.136.88.rev.sfr.net)
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03:10.57wpwrak"warning: general, unspecified threat of unknown magnitude" :)
03:11.34DocScrutinizer05http://wstaw.org/m/2014/09/14/plasma-desktopkq1987.png
03:12.02DocScrutinizer05o/
03:12.55DocScrutinizer05btw of course Conrad had no decent photodiodes
03:14.34wpwrakmail-order is your friend ;) and that way, you can get the real part already, without the need to find something sufficiently similar
03:16.04DocScrutinizer05no use for "the real part", it would look too weird when I solder wires to it
03:16.54wpwrakdoesn't strike me as unusual :)
03:37.10DocScrutinizer05btw which shop is you're using to order 3 LEDs and 3 photdiodes, and 5 opamps?
03:37.24DocScrutinizer05has it free shipping? ;-)
03:40.45wpwrakhmm, i'd search locally. and probably just go there :)
03:41.17wpwrakelse, digi-key. most convenient, most reliable.
03:43.34wpwrakthat is, with credit card. you'd want to find one that accepts paypal or that's not too messy for wiring money
03:45.49DocScrutinizer05opamp: 28ct. photodiode: 69ct, LED: 52ct
03:47.03DocScrutinizer05digikey and farnell bot minimum order 30EUR iirc
03:49.03wpwrakmaybe there are some other parts / things you'll need ?
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07:21.48DocScrutinizer05err nope
07:23.29DocScrutinizer05funy detail: somehow the red LED I used "just for fun" works better as light detector than the photodiode I got (the only one they had)
07:33.21kerio<infobot/#maemo> [02:38:27] DocScrutinizer: infobot joined!
07:33.24kerio;_;
07:43.28DocScrutinizer05sorry?
07:45.19DocScrutinizer05that's hardly a recent quote. I'm not a user of that channel anymore
07:45.44DocScrutinizer05and the chanserv command actually been an autoresponder I've set up
07:46.45DocScrutinizer05oooh, funny, the autoresponder been mine, it's not channel specific ;-P
07:50.21DocScrutinizer05http://wstaw.org/m/2014/09/14/plasma-desktopnw1987.png  I already wondered how the heck you managed it to post three lines without my irc client prepending them with your name
08:05.21wpwrakpossible IR diodes placement: http://neo900.org/stuff/werner/tmp/ir-box.pdf
09:02.52DocScrutinizer05wpwrak: looks good
09:04.38*** join/#neo900 paulk-aldrin (~paulk@armstrong.paulk.fr)
09:04.58DocScrutinizer05actually we can allow RX diode to go to an even more convenient place if needed. Sensitivity is high enough for the intended usecase, even when the diode would get mounted completely behind the TX diode. And while I'm at it: my experiments as reported above made me wonder if we actually *need* an RX diode ;-D
09:05.33DocScrutinizer05if we would allow half-duplex only, we could abuse the TX diode ;-D
09:07.40DocScrutinizer05additional funny detail: the red LED was next to completely insensitive to IR, while the photdiode received a signal sufficiently strong to show flicker on a yellow LED after a darlington, with a distance between CIR remote control and diode of 50cm
09:08.17DocScrutinizer05for white (torch) LED light the effects been exactly the inverse
09:08.56DocScrutinizer05well, not exactly, the photodiode worked better with white than the LED with IR
09:09.33DocScrutinizer05anyway clearly the LED with white beats all other pairs hands down
09:10.09enycwonders if neo900's GPS is likely to be lower power =)
09:10.28enycI observed GPS eating N900 battery like mad or something
09:10.44keriohow's a LED actually acting as a sensor?
09:11.23enyckerio: seemingly that is sonraml they have this bidirectional properyty, a photodiode is like an LED but simple tued for the purpose, or something like that ...
09:12.20DocScrutinizer05I've seen pictures of 2N3055 decanned and emitting red light ;-D
09:13.17DocScrutinizer052N3055 is a TO3 transistor and not meant to emit any light :-D
09:14.11enycSo....
09:14.12DocScrutinizer05enyc: I'm quite sure I've seen power rating about GPS as well, in PHS8 TRM/datasheet
09:14.32enycDocScrutinizer05: oh? awht waht did you learn?
09:24.40DocScrutinizer05http://wstaw.org/m/2014/09/14/plasma-desktopVI1987.png  http://wstaw.org/m/2014/09/14/plasma-desktopbF1987.png
09:24.58DocScrutinizer05so, an additional ~30mA for GPS
09:25.41DocScrutinizer05on top of the basic 46mA for WCDMA (or GSM) operation and active USB
09:26.40DocScrutinizer05even the total of 75mA is still good for a 15h continuous GPS usage, if you don't need other power hogs, like LCD backlight
09:27.01enycaah i see and this is the chip used for all wireless et.c in the Neo900
09:27.14DocScrutinizer05no, this is the modem
09:27.34enyci mmean iwiress lmoed,m , sorry being confusing
09:27.48enycWLAN etc. is indeed separate!
09:27.53enyclme looking over diagram now
09:27.59DocScrutinizer05"all wireless" would be wl1273 for wlan, bt, fm
09:28.48enyclooking at diagram the PHS8/PLS8 is either USB connected, or USB provider
09:29.56DocScrutinizer05the modem is peripheral, CPU/SoC is host
09:30.06enyckk
09:30.21enycand USB is 'safe' delineated interface from the pov of not being able to access host memory directly
09:30.32DocScrutinizer05exactly
09:30.36enycbut not against becoming a 'rouge' 'pretentd to be something else' usb device
09:30.53DocScrutinizer05err, funny idea
09:31.04enycwell the whole 'badusb' thing ...
09:31.14enycbeen made a fuss about lately ;p
09:31.19DocScrutinizer05anyway nope, the USB host is exclusively locked to the modem handler
09:31.27enycright =)
09:32.26DocScrutinizer05at least we will recommend that, it's a OS sw thing how you implement that
09:32.54enyc''trust'' wider issue very interesinng complex, no simple answers, ...
09:33.06DocScrutinizer05you are free to try and mount a mass storage device on that USB host
09:33.16enyc=)
09:33.18DocScrutinizer05;-)
09:33.39DocScrutinizer05but it's completely under your (resp OS') control
09:33.53enycis there a similar diagram for how N900 connected up ?
09:34.03DocScrutinizer05err, yep
09:34.12DocScrutinizer05in service manual L3_4 iirc
09:34.26DocScrutinizer05less detailled though
09:35.11DocScrutinizer05I might be mistaken, didn't look into L3_4 for more than a year
09:36.08enyccoo I didn't know that existed =)
09:36.34keriohold on, usb host?
09:36.41kerioah, the internal one
09:40.00DocScrutinizer05http://wstaw.org/m/2014/09/14/plasma-desktopga1987.png
09:40.26enycI'm not sure I 'evyr got N900 USB host working well
09:40.52DocScrutinizer05that took a while to spot that on page 165
09:40.52enycDocScrutinizer05: oh indeed i just got to that page was already looking at that diagram =)
09:43.02enycwondels what SSI / LoSSI serial interface is / means
09:43.19kerioRIP n900 usb otg
09:43.28DocScrutinizer05wpwrak: http://wstaw.org/m/2014/09/14/plasma-desktopga1987.png     "production test pads  <-->  UART"  ;-)
09:43.34keriowe miss you so much :c
09:44.12DocScrutinizer05SSI is slow HSI
09:44.44enycHrrm that document has a Glossary that defines neither SSI nor HSI =)
09:47.47DocScrutinizer05~wiki mipi-hsi
09:49.30DocScrutinizer05http://mipi.org/specifications/high-speed-synchronous-serial-interface-hsi
09:50.08enycinterseting this serial link was supposedly 'just' for that purpose modem -- application
09:50.13enyc'but can now be used for more stuff
09:50.21enycI guess thats' how things get built, by necessity
09:50.38DocScrutinizer05http://www.omappedia.com/wiki/HSI
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11:04.16enycnodsnods
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13:11.36wpwrak(uart to tp) it's out there ... somewhere ;-)
13:12.33wpwrak(ir placement) the box in the picture is the plastic structure in the n900 case. so there aren't all that many placement options. that is, without cutting into the box
13:13.27wpwrakbtw, clearances are in the order of 0.3 mm. so yes, if you can find a way to make do with just a single diode, that would be a major improvement :)
13:46.15enycthinks ... plastic structures
13:46.30enycwpwrak: could you find osme integrated I/R tx/rx blob ?
13:51.53wpwrakall the integrated ones i found were quite huge. with a nice distance between TX and RX, but unfortunately far too big even for the IR window in N900, let alone the box
13:52.22wpwrak(back then i didn't know about the box so i only worked with the window size. the box adds more constraints.)
13:52.45enychum
13:52.49wpwrakso going from the original single diode to two diodes will be a very tight fit.
13:52.50enycsilly question but how does the N900 do it?
13:53.14wpwrakeasy: it has one diode, not two :)
13:53.23enycit managed half-duplex ?
13:53.45enycI've never tried IR on n900  infact wasn't really waare it even existed =)
13:54.14wpwrakno, N900 is TX only. for CIR. no IrDA or such.
13:54.49wpwrakyeah, i suspect that the fancy IR capabilities of neo900 will go greatly underappreciated in the field
13:55.01kerioto be completely fair, TX is probably what you want
13:55.14kerioalthough it's nice to be able to read a remote instead of having to select it from a list
14:03.51enycis the tight-fit IR separate diodes doable??
14:04.15enycI mean we know this was all going to be a squeeze anyway....
14:10.10keriohow's battery hotswapping supposed to happen?
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14:26.45wpwrakmaybe we should pick a smaller diode. VEMD10940F looks friendlier. and has better availability. less sensitive and has a very wide angle, but all that's probably more feature than bug. of course, it'll doom full-duplex even more :)
14:35.39wpwrakso that would be the plan B: http://neo900.org/stuff/werner/tmp/ir-box2.pdf
14:37.17wpwrakminimum clearances increase to 0.5 mm and the height at the rear (may become important when rotating the pcb into place) goes down from 2.3 mm to 1.0 mm
14:39.37wpwrakas a small undeserved bonus, the part is even orderable at digi-key: http://www.digikey.com/product-detail/en/VEMD10940F/VEMD10940FCT-ND/3915201
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14:43.17*** join/#neo900 Nokiabot (~Nokiabot@223.176.22.88)
15:00.48NokiabotVivrator is an awsome invention thats cratering our varied needs daily from pleasure to reinforcing concrete to  notifications on communication devices to dancing 6310 so who knows  what the heck a dozen pair of vivrators on neo900 could be used for.. :)
15:03.38NokiabotOnly limited by ones imagination if there are a couple of vivrators be available on neo900 to spare :p
15:05.10jake42vivrator O.o
15:05.41wpwrakNokiabot: here's some industrial design homework for you: enhance the stylus such that it a) is suitably inflatable, and b) has a built-in supercap-powered vibration device
15:06.05jake42interessting how prices for VEMD10940F differs between digikey and mouser..
15:06.09NokiabotJake42:you seem to get my point :)
15:07.28NokiabotWpwark:keep your nefarious intentions to yourself :p
15:08.22jake42oh.. me beeing stupid.. mouser is €, digikey is $
15:09.39NokiabotHonestly what harm a couple of vivrators would do provided if there is enough space for one more atleast :)
15:13.47NokiabotWpwark:btw what is that supercap vivrator thingy :p
15:15.17Nokiabot~Botsnack
15:15.17infobot:), Nokiabot
15:16.50NokiabotOo so this is highlighting was wondering on the changed fonts :p
15:36.31NokiabotWpwark:i see most chineese craps have torch with a hardware switch  which works even when the phone is off a very useful function indeed so if possible feisable can same be done with flash leds using any of the switches like vol button maybe :)
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15:37.25drathirmornin...
15:38.34NokiabotNight...
15:39.38*** join/#neo900 Sicelo (Sicelo@gets.high.on.ircspeed.net)
15:48.55Nokiabotdinner over 18 chappatis in cant move now :p
15:49.53*** join/#neo900 xe4l (~unknown@162.243.112.233)
16:02.51wpwrakah, here :)
16:03.17wpwrakyes, i think the flash controller has a "torch" mode
16:03.33wpwrak(with reduced current, so the led doesn't burn up)
16:04.22NokiabotErr read it again i stated something diffrent
16:07.11NokiabotWpwark:no you didnt get it
16:13.58NokiabotOo
16:14.31Nokiabotwpwrak:...
16:28.34drathirwpwrak: if good remember depend which kind of flash light used some of them dont like continious long flashing...
16:50.14wpwrakdrathir: yes, LEDs have a certain maximum pulse current (for a very short time) and a lower maximum continuous current (for as long as you want)
16:51.22wpwrakcontinuous current is basically how fast the package can dissipate the heat generated by the junction
16:52.12wpwrakmaximum pulse is the thermal capacity of the junction. at the end of the pulse, it would be at its maximum allowed temperature. then you have to turn off to let it cool down again
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16:53.37wpwrakwe've actually mentioned this in http://neo900.org/stuff/papers/ir.pdf (page 10, last paragraph)
16:53.48wpwrak(mentioned) very very briefly, though
17:04.50drathirthe project with all days amazing me more and more...
17:05.29drathirwpwrak: possitive way ofc...
17:42.41wpwrakheh, thanks ! :)
17:44.27drathirwpwrak: its np...
18:05.49enycwpwrak: supposedly IrDA is halfduplex light anyway anyway
18:07.44DocScrutinizer05yep
18:08.02DocScrutinizer05exactly what I recall as well
18:09.07DocScrutinizer05it's just about IR-UART which wouldn't understand ^S/^Q anymore
18:09.18DocScrutinizer05;-)
18:10.12DocScrutinizer05but I don't see why duplex gets affected by placement or type of RX semiconductor
18:10.37enycDocScrutinizer05: in as much as the transmitter overwhelms the local receiver
18:10.41DocScrutinizer05sensitivity yes, duplex however...?
18:10.59DocScrutinizer05no, we compensate for that
18:11.15enychow??
18:11.37DocScrutinizer05and our S/N is pretty good for the planned usecase, no matter what the receiver placement
18:12.02DocScrutinizer05how? simple feedback
18:13.01DocScrutinizer05when I know my TX crosstalks with gain G to RX, then I simply have a direct electrical feedback with -G
18:14.02DocScrutinizer05that's really EE 101
18:16.04DocScrutinizer05(actually the term "feedback" is slightly misleading, it's a forward compensation)
20:14.23jake42DocScrutinizer05: hi, while I was composing a email to the list of our fablab, I realized I still have a hard time imagining how spacer frame and the two pcbs are supposed to fit together
20:15.35jake42is the frame supposed to go on top or in between both pcbs?
20:27.21wpwrakjake42: there are two spacing issues: one part that provides a bit of sidewall and integrates the keyboard frame. this part is what we call the "spacer frame"
20:28.53wpwrakthere other is for distributing pressure from the top board downward. this one is less clearly defined. DocScrutinizer05 wants to add metal spacers to the upper board. i think a plastic structure would be both easier to make and more versatile.
20:29.49jake42so there will be a visible "external" frame and a invisible "internal" one
20:30.49jake42part of the external one should be shaped like the original kbd-frame
20:32.45wpwrakyes, exactly
20:33.28DocScrutinizer05no, I never said I want to use "metal spacers"
20:33.45DocScrutinizer05you completely missed that
20:34.28DocScrutinizer05I already elaborated there is no use in any plastic filling the (non-existent) empty space between UPPEr and LOWER
20:36.00wpwrak"metal force propagators" then ?
20:36.01DocScrutinizer05what I said is to have rigid steel posts (like nails or contact posts) soldered to UPPER and reaching through holes in LOWER to finally sit on bottom of case
20:36.18wpwrakyes, that's what i mean. post = spacer
20:36.55DocScrutinizer05jake42: see http://neo900.org/stuff/joerg/spacerframe/sketch.pdf
20:36.57wpwrakand i still think that this is more easily done with plastic. exact shape to be defined.
20:37.07jake42so UPPER will part lie partially on modem?
20:37.13DocScrutinizer05NO!
20:37.25DocScrutinizer05that's a sure way to break stuff
20:37.46jake42what is filling the empty space?
20:37.56DocScrutinizer05nothing
20:38.06wpwraki kinda wonder what sort of forces you expect on that keyboard ...
20:38.07DocScrutinizer05a) there's not much of empty space anyway
20:38.14jake42how is it non-existant?
20:38.24DocScrutinizer05b) we need that to *avoid* any force to modem
20:39.20DocScrutinizer05UPPER and LOWER are a PCB sandwich with component spread
20:39.28jake42but there will be ~2mm headroom between both pcbs (expet where there are components)
20:39.31jake42right?
20:39.47DocScrutinizer05exactly, *expet where there are components*
20:39.58jake42good
20:40.17DocScrutinizer05there will be components virtually everywhere
20:40.24jake42so the idea with those metal posts seems reasonable to me
20:40.40DocScrutinizer05[2014-09-14 Sun 22:34:28] <DocScrutinizer05> I already elaborated there is no use in any plastic filling the (non-existent) empty space between UPPEr and LOWER
20:41.28wpwraksigh. not filling, being there, to distribute the load. what would be the point of "filling' ?
20:41.58DocScrutinizer05we must not "distribute the load"
20:42.18jake42so if you type on the kbd one usually squeezes the button on top and the back of the device together
20:42.19DocScrutinizer05LOWER must not get mechanically coupled to UPPER
20:43.11DocScrutinizer05any "load" has to get supported from case bottom, not from LOWER
20:43.15wpwrakwhy would distributing the load imply coupling with LOWER ? you can still have all the holes and posts you want.
20:43.25wpwraki think you're mixing up concept
20:43.26wpwraks
20:43.39wpwraka) take load from UPPER -> distribute it downward
20:43.44DocScrutinizer05I'm pointing out that your concept is not exactly clear
20:43.58wpwrakb) see what works best down where
20:45.40wpwrakanyway, so hacklab will be in charge of ME ?
20:46.02wpwrakbecause then i won't look into making a spacer frame
20:46.14jake42DocScrutinizer05: so you think it will be enough support for the kbg from the 4 posts
20:46.24DocScrutinizer05any plastic "nails" will have to be much thicker in diameter than steel, and you cannot solder them but need some relatively huge structure on top side of UPPER to fix them there
20:46.49DocScrutinizer05jake42: did I say this?
20:47.12jake42wpwrak: don't know yet, have to inquire first. hacklab per se doesn't do anything. you have to do it yourself. but maybe someone is willing to do it
20:47.22jake42DocScrutinizer05: sry, this was ment as a question
20:47.26DocScrutinizer05I don't even know what are "THE 4 posts"
20:48.25DocScrutinizer05[2014-09-14 Sun 22:36:01] <DocScrutinizer05> what I said is to have rigid steel posts [edit: several, like 6 or 8] (like nails or contact posts) soldered to UPPER and reaching through holes in LOWER to finally sit on bottom of case
20:48.38jake42so sorry again. I imaginged that the posts you mentoned will be where the 4 screws go
20:49.46jake42DocScrutinizer05: thanks, know the image in my head should be more syncronizied with your idea :-)
20:50.04DocScrutinizer05:-D
20:50.10jake42s/know/now
20:50.42jake42to an extend nothing goes over discussing ideas
20:50.49DocScrutinizer05most of them posts will end with their tip on inside of the battery bay steel
20:53.33jake42will the 4 existing posts in the display half also be "made" longer?
20:53.43DocScrutinizer05we anyway can place them relatively arbitrarily to wherever they don't conflict with modem or large chips (we don't want to drill holes into those components)
20:53.48wpwrakthis limiting factor for the minimum thickness of such posts is likely the amount of lateral force they experience (in relation to their ability to distribute this to whatever they attach to), not compressive strength. so a high-strength material alone isn't enough - it also has to be prevented from titling
20:54.00DocScrutinizer05jake42: those get spacer washers
20:54.11jake42DocScrutinizer05: ok, good
20:55.45DocScrutinizer05it seems that in N900 original design those bolts sit on top of PCB (which in N900 is LOWER) and thus fix it when you tighten the screws
20:56.37DocScrutinizer05in N900 they will sit on top of UPPER then, pressing it down when tightening screws, against the washers and LOWER
20:58.03DocScrutinizer05s/N900/Neo900/;  the thickness of UPPER PCB plus washers will define how much higher the display is in Neo900 than in N900
20:58.41DocScrutinizer05this is 2mm for "empty space" (where components live) plus 0.8mm for PCB
20:58.53DocScrutinizer05--> 2.8mm
20:59.06DocScrutinizer05which our spacer frame needs to compensate for
21:00.09jake42from your sketch I looks to me like the spacerframe will also add to the vertical thickness
21:00.35DocScrutinizer05that's sloppy sketch then
21:00.40DocScrutinizer05it shouldn't
21:01.37DocScrutinizer05that sketch is just illustrative to explain the idea. It doesn't contain and design details that are useful to use them as specs
21:01.44jake42as the posts where the screws go in will go through the sketched holes
21:02.01DocScrutinizer05wpwrak: nope, fablab is not in charge to make a spacerframe yet
21:02.43DocScrutinizer05however I thought you were not fond of the idea of doing it
21:03.19DocScrutinizer05didn't we discuss 3D CAD and that we both don't really like to mess with that sort of application?
21:04.18DocScrutinizer05if you feel like doing the 3D modeling, you're more than welcome
21:04.24wpwrakjake42: i'd say that the spacer frame largely defines the thickness (since it has to close "nicely"). but of course, the parameters for the desired addition come from elsewhere
21:05.42wpwrakDocScrutinizer05: yes, my capabilities here would be limited to a rough shape: machined from only one side (2.5 D), and with a rather crude CAD side
21:05.55DocScrutinizer05no, the needed clearance for components plus the thickness of PCB defines the spacerframe
21:06.40wpwrakbasically at the level of what i've done for anelok. but at the hacklab you should be able to find better facilities.
21:06.46DocScrutinizer05we're talking 3D CAD modeling. Not CNC milling or 3D printing
21:06.54jake42wpwrak: of course, I meant that sketch has holes in the frame which might even make sense for stability, though also might add to thickness
21:07.26DocScrutinizer05jake42: yes, I actually made a mistake there maybe
21:08.19DocScrutinizer05the holes need to be large enough to let the complete display bolts pass through, but probably should be precise enough to stabilize the spacerframe
21:08.49wpwrak(3d model) fped here. not what it's meant to be used for, but all the alternatives just seem to suck even more ;-)
21:08.50jake42now we're talking :-)
21:09.37jake42openSCAD looks fun ;-)
21:10.05DocScrutinizer05I pondered whether we could make the spacerframe go in between the sandwitch to replace the washers in the "hole area", but that's pretty complicated
21:10.15wpwrakjake42: it looks nice but it never seems to be willing to do quite what i want ...
21:11.14wpwrakDocScrutinizer05: so you'd insert the upper PCB horizontally into the spacer frame ?
21:11.33DocScrutinizer05that's why I say "that's complicated"
21:11.41wpwrakyeah :)
21:12.14DocScrutinizer05the spacer frame concept isn't 100% finalized yet
21:12.35wpwrak3D printer or a fancy mill or fancy tools. not impossible but considerably harder
21:12.42DocScrutinizer05I'm hoping for the ME guys to know their business
21:13.10jake42DocScrutinizer05: good to know
21:13.16wpwrakis there local expertise at the hacklab you can recruit ?
21:13.33jake42it's at the university
21:13.46wpwrakaah ! :)
21:13.46DocScrutinizer05*maybe* we actually could slide in UPPER and then plug LOWER to it, but that would basically result in a block of stuff that's impossible to mount to the case then
21:13.49jake42run by students
21:14.36DocScrutinizer05I think it's not feasible to plug an UPPEr to a already mounted LOWER
21:14.52jake42if anyone wonders: https://fablab.fau.de/
21:15.24jake42(germany only, sry)
21:15.39DocScrutinizer05so the most likely procedure to assemble is: plug UPPEr onto LOWER, mount the sandwich to case, then mount spacerframe to that
21:16.26DocScrutinizer05which would rule out any idea of having spacerframe go between UPPER and LOWER and act as "washers" there, aiui
21:20.56jake42hm.. I'm not yet satisfied with this discussion but some other time
21:20.57DocScrutinizer05probably we should just use washers large enough in diameter so they will support the spacerframe against getting pushed in from side
21:21.49jake42good night.. gotta catch some sleep before the craftsman show up in the morning
21:21.51DocScrutinizer05note that UPPER needs some clearance to spacerframe, or any tiny impact will break the B2B connectors between UPPER and LOWER
21:22.15jake42good point!
21:22.16DocScrutinizer05jake42: good night! :-)
21:22.39jake42cya
21:23.19DocScrutinizer05only thing sturdy enough to take such lateral impact are the 6 screws
21:24.26DocScrutinizer05thus have washers sitting between UPPEr and LOWER and fixed by such screws which are large enough in diameter to support the outer structure which will take the impact: spacerframe
21:25.46DocScrutinizer05this should work for 3 of the corners, lower right corner is a tad off and thus needs some more care to design this detail right there
21:27.40DocScrutinizer05I'd love to discuss all those little design details with the guy creating the spacer frame 3D-CAD model
21:34.46DocScrutinizer05wpwrak: maybe those "washers" could actually be made of metal or plastic in a CNC, to optimally adapt to the sandwich shape and maybe even have tine bolts/noses that latch into 1mm holes in upper and lower to keep the "washer" thingies in place during assembly
21:35.47DocScrutinizer05s/tine/tiny/.
21:37.31wpwrakcareful: if it's upper AND lower, you need two-sided machining again. (or a good 3D printer)
21:37.49DocScrutinizer05yeah, already thinking about that
21:38.10DocScrutinizer05prolly "either or" is enough
21:38.21wpwrakone problem with 3D printers is that you don't have a lot of choices for the material. if you're lucky, what they use just happens to work for you. else, you lose. it's pretty much all or nothing.
21:38.41DocScrutinizer05spacerframe also needs some way to fix it to case at upper end next to the buttons
21:39.36wpwrak(or) yes, should do. if you want to get fancy, you could add holes for screws to do the other side. through-drilling is quite doable. but then, this weakens the material and requires a tool change. so something to not consider lightly.
21:39.43DocScrutinizer05not that it could move too much in Z-axis up since there's display which stops it, but we don't want a dangling flimsy plastic thingie there
21:40.41wpwrakyou mean the thin "bridge" that in n900 has extensions that slider under cans and some vaguely Z-shaped metal structure ?
21:41.02DocScrutinizer05(screws) thought about that, do somehow fix UPPEr and LOWER together, even without getting squeezed between case shell and display bolts
21:41.43DocScrutinizer05no I mean the parallel structure to that, which is part of the outer case wall next to the buttons
21:41.48DocScrutinizer05switches
21:41.55DocScrutinizer05power and volume
21:42.32wpwrakah yes, that one will be quite fragile, too
21:43.13DocScrutinizer05idly wonders if we shouldn't use a 2-pats design consisting of a mere spacer frame and a separate (original) kbd frame, and the *glue* the spacerframe to case
21:43.15wpwrakwell, so-so. it's almost 3 mm thick. that's a fair bit of material
21:43.29DocScrutinizer05parts*
21:43.51DocScrutinizer05and then*
21:43.59wpwrakthat seems to be both more complex and less stable
21:44.05DocScrutinizer05yes
21:44.28DocScrutinizer05unless the glue is strong
21:45.13wpwrakthat way, you probably also miss the opportunity to stabilize the spacer frame in the middle
21:45.47wpwrakor rather, "an opportunity"
21:45.56wpwrakin general, the simpler, the more stable :)
21:46.08DocScrutinizer05the whole opportunities are in glue with such design
21:46.21DocScrutinizer05but I also think it's not feasible
21:50.19DocScrutinizer05maybe several of those "problems" could get mitigated if we use alu or even steel for the spacerframe
21:51.08DocScrutinizer05RF design should not see any impact from that, since all antennas are on opposite side of the PCB
21:52.40DocScrutinizer05I'd hope dural or steel would be less flimsy and allow for fewer fixing points e.g along the upper buttons "bridge"
21:52.57wpwrakbut also a lot harder to machine
21:53.32wpwrak-> $$$
21:54.14DocScrutinizer05yep, I know
21:55.38DocScrutinizer05anyway steel would probably even allow for a 2  0.1mm thick 2ears" with holes in them, at upper right and left side, to actually fix the frame *under* the display bolts
21:56.00DocScrutinizer05we could reduce PCB thickness by 0.1mm accordingly at that area
21:56.17DocScrutinizer05HMMMM
21:57.07wpwrakwe we going to left-shift the price of Neo900 a bit ? :)
21:57.07DocScrutinizer05who says UPPER needs tho get fixed by the display bolts at all? maybe some latch on spacerframe coult fix it instead
21:58.01DocScrutinizer05wpwrak: we cannot design stuff from a "we got xx bicks, now let's see what we can do for that amount" perspective
21:58.11DocScrutinizer05bucks even
21:59.16DocScrutinizer05when spacer frame isn't working in acrylic, we need to investigate other alternatives, then after we found all solutions that may actualy work, we check which is the most economic one
22:00.16DocScrutinizer05I had dural CNC stuff made already, been $$, not $$$
22:01.10DocScrutinizer05when spacer frame costs 15 bucks then we will survive that, even when it's not nice. We even will *survive* 50 bucks per frame
22:01.48DocScrutinizer05spacer frame is a mission critical part. It has to just work
22:02.55DocScrutinizer05we cannot do somthing that "somehow works" and gives us the benefit of only costing 2 bucks per frame but gives us all sorts of annoyances and problems
22:03.46DocScrutinizer05spacer frame already is a botch by design. So let's at least try to make something that doesn't suck too much
22:05.08DocScrutinizer05as a first simple rule, you must not be able to destroy the spacerframe by pressing at it with your fingernail
22:08.37DocScrutinizer05zinc cast comes to mind
22:08.58DocScrutinizer05need to check what's the options and cost with that one
22:10.40DocScrutinizer05most likely way too expensive since aiui you need those damn molds again. Same situation like with case
22:14.54wpwrakregarding cost, plastic = $, aluminium = $$, steel = $$$. and yes, casts cost
22:15.14DocScrutinizer05souds about right
22:19.12DocScrutinizer05sill not off the table: make UPPER PCB so large that it creates the outer wall of case on that level
22:20.22wpwraksounds like a bag of problems :)
22:20.45wpwrakand unless you gold-plate the sides of the pcb, it'll look shitty
22:20.46DocScrutinizer05have a thin rubber sealing between UPPEr and the rim of case shell. Mount UPPER to case shell rigidly via the 6 screws we have. Mount LOWER only to UPPER then, giving it some clearance to case shell
22:21.13DocScrutinizer05I planned to do exactly that gold plating, but Nik told me "can't get done"
22:21.27wpwrakoh, it can, but it has a price ...
22:21.44wpwrakalso, the fancier the pcb spec, the fewer fabs that can make it
22:21.54DocScrutinizer05is that price higher than a spacer frame of palstic, alu, steel, zinc?
22:22.16wpwrakbut you still need the spacer :)
22:22.27DocScrutinizer05huh?
22:22.36wpwrakwell, or some piece of plastic. whatever you call it
22:22.47wpwrakyou need a keyboard frame
22:22.54DocScrutinizer05we need a kbd frame then, that's true
22:23.15DocScrutinizer05that however would look pretty simple then
22:23.56DocScrutinizer05could get mounted to UPPER with a few screws *before you marry the sandwich
22:24.33DocScrutinizer05assembly would be dead easy
22:24.55wpwrakand your new keyboard frame also needs to provide a bit of wall all around the device
22:25.09DocScrutinizer05lterally drop in the whole sandwich incl kbd frame into case shell, fix with the screws
22:25.21wpwrakgranted, you can now glue all the plastic to the upper board, but ...
22:25.45DocScrutinizer05not glue, screw
22:26.14wpwrakin any case, you would have exactly the same options also if the pcb is not part of the outside
22:26.24DocScrutinizer05no
22:26.48DocScrutinizer05impossible to assemble, way more complex frame, less rigid design
22:27.09wpwrakalso, if pcb goes to the outside, you have a rigid mechanical connection. so anything that hits the device will go straight to the connectors and such
22:27.22DocScrutinizer05you cannot fix the spacer frame as we have it now with screws to UPPER
22:27.44DocScrutinizer05no, since I mounted LOWER to UPPER
22:28.39DocScrutinizer05>>Mount LOWER only to UPPER then, giving it some clearance to case shell<<
22:29.02wpwrakwell, think a bit about all the places where things mate and you'll see where you run into problems
22:29.33wpwrakyou've basically divided one problems into two, each roughly of the same magnitude as the original
22:29.34DocScrutinizer05I already did. I had that idea... some time ago
22:30.35DocScrutinizer05why don't _you_ "think about all the places" so I could check what I missed?
22:30.51wpwrakhow would it connect to the bottom shell ? just lie flat on top ? or try to have a rim ?
22:31.10DocScrutinizer05flat, rim, we can do both
22:31.26DocScrutinizer05some "latches"
22:31.56DocScrutinizer05basically it gets fixed by the 6 screws
22:32.34wpwrakfor them rim, you'd need a very fine structure. there you may actually have no choice by to use some metal
22:32.53DocScrutinizer05why do we need such fine structure?
22:32.58wpwrakon the other side (rear), you have no choice but have the pcb rest flat on the case
22:33.31DocScrutinizer05maybe I already missed what we're actually talking about
22:33.41wpwrakalso, how would all this give you the 2 mm internal separation between upper and lower ?
22:34.35wpwrakactually, lemme check this one
22:36.13*** join/#neo900 MonkeyofDoom (~~~~~~~~Mo@71-14-188-191.dhcp.stls.mo.charter.com)
22:37.49DocScrutinizer05http://projects.goldelico.com/p/neo900/issues/518/#ic1581
22:37.54wpwrakhmm, distance between top of upper and the edge of the bottom shell is about 1.9 mm
22:38.35DocScrutinizer05and bottom of the one before
22:39.12DocScrutinizer05till http://projects.goldelico.com/p/neo900/issues/518/#ic1585
22:42.50DocScrutinizer05the distance between upper side of LOWER and the rim of case shell is < 2mm
22:43.04wpwrakso you a) need a structure on top of UPPER-XL that provides keyboard frame and the part of the wall that normally comes from the bottom case shell
22:43.16DocScrutinizer05distance betwee upper side of LOWER and lower side of UPPEr is 2mm
22:43.31DocScrutinizer05a) yes, exactly
22:43.57wpwrakand b) if you want to have a rim at the bottom you need some thin U-shaped structure on the pcb there as well
22:44.05wpwraklemme check the dimensions of that
22:44.57DocScrutinizer05elastic and ~0.2mm thick. See http://projects.goldelico.com/p/neo900/issues/518/#ic1585
22:46.47DocScrutinizer05we however should have some non-elastic distance blocks in there, so forces to UPPEr like key pressing (or impact from fropping device) will not give all load only to those distance nails I mentioned above
22:47.03DocScrutinizer05dropping*
22:47.46wpwrakthat U-structure would have to be 1.2 mm - tolerance tall. width from 0.5 mm to as much as you want
22:48.41DocScrutinizer05the new (now only) kbd frame would get mounted to UPPER by a few screws you drive in from bottom side of UPPER to hold frame in place
22:48.56DocScrutinizer05sorry?
22:49.21DocScrutinizer05where from are those 1.2mm?
22:49.31wpwrakU-structure to connect to the rim of the bottom shell. making sure board and shell don't bend away from each other too much
22:49.39wpwrakthat's the depth of the rim
22:50.12DocScrutinizer05oooh that one, we don't care about that stair in there anymore
22:50.51DocScrutinizer05well, we could
22:51.19wpwrakwould make the thing less wobbly
22:51.30DocScrutinizer05but we also can go "deeper" and support the case where it has its full wall thickness
22:51.47wpwrakyes, that's what you would have to do on the rear side
22:51.56DocScrutinizer05exactly
22:54.06DocScrutinizer05maybe use slightly triangle shaped noses that are from kbd frame and go through holes in PCB to form the support structure?
22:54.14wpwrakadding rubber sheets to the stack is likely to be messy if they go all the way to the edge: a) you get even more parts that need to be finished with very high precision (and rubber !), b) they're likely fray and to trap dirt, so that edge will probably look messy
22:54.38DocScrutinizer05good point
22:54.48wpwrak(triangles) that would be an option, yes
22:56.18DocScrutinizer05we don't want foam or rubber or sth like that there
22:56.32wpwraknoises would also improve xy registration between the top plastic and the upper board
22:56.47DocScrutinizer05yes, that been the idea
22:58.12DocScrutinizer05Nik will kill us both for binning the complete ME-testing done in V0 when we go this path
22:58.39wpwraki thought most of the ME was on LOWER ?
22:58.47wpwrakME testing i mean
22:59.03DocScrutinizer05yes, exactly, and LOWER must not touch the case in this stacking
22:59.33wpwrakwell, it can touch it. just mustn't snap into it
22:59.53DocScrutinizer05in this stacking it's UPPER that needs to fit to the case, and LOWER needs the clearance we now have on UPPER (tentatively)
23:01.02DocScrutinizer05we need that clearnace to allow deformation and thermal/other shape distortion will not create shearing forces to the B2B connectors
23:01.35DocScrutinizer05I actually hate the fact that those B2B have so few x/y "elasticity"
23:02.03wpwrakif you screw lower to upper then the spacers you use for that will take these forces
23:02.08DocScrutinizer05Nik already searched for some that have maximum x/y clearance available
23:02.33wpwrak(spacer taking forces) which of course means that, as you tighten them, they may break your b2b if you're not careful
23:02.46wpwrakwell, plan B would be FPC (-:C
23:03.10DocScrutinizer05that would be great, from an ME / EE POV
23:03.39DocScrutinizer05not though from a components sourcing and selection POV
23:04.14wpwrakdo it nokia-style ? ;-)
23:05.18DocScrutinizer05err yes, technically that would actually be feasible
23:05.45DocScrutinizer05though wasting a ~ 3cm^2 PCB real estate
23:06.43DocScrutinizer05but then we have 8-layer on both PCB, and that embedded FPC stuff is expensive and extremely nasty
23:07.08wpwraki imagine it to be
23:09.27DocScrutinizer05FPC is great, but only with a connector on both ends
23:09.42wpwraki still suspect that in this kind of stack, things can easily shift out of alignment. so you may have the pcb stick out some 0.2 mm at some place, suffer abrasion, etc.
23:09.45DocScrutinizer05kinda like GTA02 debug cable
23:09.59wpwrakand we all know just how much that one sucked :)
23:10.36DocScrutinizer05well, it's not meant to withstand abuse by user
23:10.39wpwrak(gta01/02 debug) well, you've been spared the worst i think
23:10.58DocScrutinizer05?
23:11.03wpwrakoh, it didn't need abusive users. we've all been very very careful ;-)
23:11.24DocScrutinizer05FPC are for inside a device
23:11.44DocScrutinizer05there they work just fine
23:12.19wpwrakwe had basically everything possible go wrong with these cables. and it was a pita to even get it manufactured. and the junk they sent us was mostly garbage.
23:12.59DocScrutinizer05:-/
23:13.26wpwrakgta02 side too wide (so you had to trim it with a cutter), board side too wide/small/off-center, so you had to wiggle it around until you had enough signals connect (no point in hoping to get all at the same time)
23:13.41DocScrutinizer05doesn't mean this is system immanent
23:14.18wpwrakthen material fatigue in the connector on the board. and the copper in the fpc broke very easily, just by regular bending. no abuse needed.
23:14.56wpwraki mean i made some support structures that held the whole mess in place to avoid any load whatsoever on the precious fpc ...
23:16.03wpwrakyes, i think that one was the worst fpc experience possible. it can only get better from there ;-)
23:16.37DocScrutinizer05the wuestion is: could we get a FPC (possibly even some off-the-shelf stuff) that sucks less re quality, and can we get some connectors for that too?
23:22.09*** join/#neo900 freemangordon (~freemango@46.249.74.23)
23:23.03wpwrakthere may be some short parallel ones
23:23.11*** join/#neo900 nicksydney (~quassel@197.139-50-210.dynamic.dsl.syd.iprimus.net.au)
23:23.11wpwrakhow many signals do we need ?
23:23.48wpwrak(digi-key: Product Index > Cable Assemblies > Flat Flex, Ribbon Jumper Cables)
23:24.20wpwrakthere should also be solderable such critters. but digi-key doesn't seem to have that kind
23:25.52wpwrak(solderable) like on this critter: http://www.buydisplay.com/media/catalog/product/cache/1/image/c577d1203d4a53d9f98182eb6081b1d6/s/e/serial_spi_1.3_inch_128x64_oled_display_module_ssd1306_white_on_black_1.jpg
23:25.54DocScrutinizer05err, dunno, what have we got so far? 2 pcs 60pin
23:26.42DocScrutinizer05yeah, soldering one end is a reasonable option
23:27.46DocScrutinizer05I'm pretty sure those rigid 60pin B2B-conn will eventually give us headache
23:28.10wpwrak2 x60 ? hmm. that's a lot.
23:28.26wpwrakhere's one with 40. 0.5 mm pitch, 17 mm long: http://www.digikey.com/product-detail/en/050R40-17BO/RE109-010-ND/2263535
23:28.33*** join/#neo900 Neros_ (~quassel@128-79-158-242.hfc.dyn.abo.bbox.fr)
23:29.02wpwrakand i'm sure china has some cheaper ones ;-)
23:29.16DocScrutinizer05well, 3 of them will replace 2 pcs 60pin B2B
23:29.38DocScrutinizer05WTF? 20 bucks?
23:29.47wpwrakyou found it ;-)
23:30.04wpwrakthat's just digi-key's hopelsss patriotism
23:30.24DocScrutinizer05awesome datasheet¡
23:31.39wpwrakthe L variants may be interesting: "lasered". that could be the soldering holes
23:32.02DocScrutinizer05:nod:
23:32.30DocScrutinizer05idly mused about that Z-axis connecting sticky tape
23:32.54DocScrutinizer05but that's not as reliable as we would like it to be, I guess
23:33.38DocScrutinizer05though industry seems to actually use it for exactly such stuff like attaching FPC to glass of LCD
23:37.30wpwrakhmm. 4pcb.com have "gold fingers" which is on the "edge". but only options are 0-2 sides.
23:37.52DocScrutinizer05hm?
23:38.07DocScrutinizer05what is 2gold fingers"?
23:38.42wpwrakah, plated edges is if what we'd want. alas, "(Pricing Subject To File Review) "
23:38.54wpwrak(2) gold fingers on 2 sides
23:39.01DocScrutinizer05aaah, PCB gold rim
23:39.48DocScrutinizer05I dunno, the PCB edge looks pretty clean
23:41.27DocScrutinizer05but gold edges (actually segmented, for contacts) would be great
23:42.00wpwraklet's see ... 8 layer, didn't specify anything fancy. with gold fingers on 2 sides, 2 week: USD 529 tooling, then USD 49.68 @ 50
23:42.30DocScrutinizer05for the plating alone?
23:42.32wpwrakwithout gold fingers: same NRE, USD 38.60 @ 50
23:42.36DocScrutinizer05aaah
23:42.54DocScrutinizer05now that doesn't sound bad at all
23:43.03wpwrakwhole pcb. but under-specified. we probably need some fancy stuff that would make it non-quoteable
23:43.25wpwrakthat's just fingers. full edges may be harder
23:43.32wpwrakbut at least it's a start :)
23:43.39DocScrutinizer05expected as much. wouldn't see why via plating is cheap and edge plating cost more than gold (literally)
23:43.57wpwrakusual process -> $$$ :)
23:44.24wpwrakby and large it's always the same
23:45.34DocScrutinizer05>>And when we already have gold there, why not make this a few cotact pads for e.g. charger-cradle pogopins to contact there. <<
23:46.04DocScrutinizer05http://projects.goldelico.com/p/neo900/issues/518/#ic1581
23:46.39DocScrutinizer05with FPCs we could even keep LOWER ME as is
23:46.42DocScrutinizer05\o/
23:47.21DocScrutinizer05neither orientation nor distance between UPPER and LOWER would have to match to the 1/10
23:48.16DocScrutinizer05sou we would mount UPPEr on top of LOWEr only loosely
23:48.54DocScrutinizer05weird how my typng always fails to keep the shift key pressed on ending "r"
23:50.19DocScrutinizer05mucle memory needs retraining
23:50.19wpwrakthe fpc idea is also orthogonal to what happens with the spacer frame
23:50.28OksanaDocScrutinizer05how the heck Oksana was able to tell we use pelican? I didn't recall the name
23:50.30OksanaSee file "pelicanconf.py"? http://neo900.org/git/?p=www;a=tree
23:50.45DocScrutinizer05:-D
23:52.07DocScrutinizer05wpwrak: please explaon "orthogonal"
23:52.23DocScrutinizer05in context
23:52.42DocScrutinizer05or simply, please rephrase
23:55.18wpwrakindependent from
23:55.27DocScrutinizer05wpwrak: aah then I disagree
23:56.01DocScrutinizer05with FPCs we could even keep LOWER ME as is
23:56.44wpwraki was more thinking of fpc also being an option with the old design that keeps the pcbs inside
23:57.07DocScrutinizer05aaah
23:57.13DocScrutinizer05yes, of course
23:57.31DocScrutinizer05and I meant that B2B conns will give us headache either way
23:57.48DocScrutinizer05I don't like them for the stacking we got right now either
23:57.51wpwrakyes, it looks as if they had a good chance of doing so
23:58.47DocScrutinizer05if we could go s/B2B/FPC/ we *should* do this
23:58.55wpwrakyou'd basically want a rigid package: e.g., upper screwed (with spacers) to lower, then b2b in the middle. so all stress goes to the spacers
23:59.19wpwrakor fpc to connector board, like nokia did the display
23:59.27DocScrutinizer05:nod:
23:59.58wpwrakb2b as mechanical support works great in the arduino world, but ... :)

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