<DocScrutinizer>
zrafa: more like 3 years older than 30: blit 1981, X11 1984
<whitequark>
DocScrutinizer: thanks a lot for your suggestion about solder mask/silkscreen removal
<whitequark>
I've improved it a bit: if you use a sharp needle, it's easier to not accidentally split some important trace in two
<DocScrutinizer>
whitequark: sorry I don't actually recall what I suggested and for what
<whitequark>
hmm
<whitequark>
looks up the logs
<wpwrak>
DocScrutinizer: if he used a knife, it was probably me. if he used the dark side of the force, all the credit it yours ;-)
<wpwrak>
DocScrutinizer: that suggestion was about removing stuff that covers traces
<DocScrutinizer>
o.O
<whitequark>
whoops
<whitequark>
sorry, that really was Werner
<DocScrutinizer>
aaah
<whitequark>
for some reason I remembered you as the author of the advice...
<DocScrutinizer>
well, maybe because it is quite probable that you'd get such kind of advice from me
<whitequark>
wpwrak: yep, I've tried with a knife. using needle is more precise, i.e. I do need the solder mask for 8WSON a lot, but please, no pad-covering silkscreen
<DocScrutinizer>
I'd nevertheless use a small "round" knife and carefully scrape (NOT cut!) soldermask away
<wpwrak>
if you solder manually, it actually doesn't mater all that much. it's the flux that does most of the magic. but yes, silk screen on pads = evil ;-)
<DocScrutinizer>
soldermask on pads == BUG
<whitequark>
wpwrak: yes, flux is very important too, but if I have exposed traces, solder tends to leak to the uncovered places and makes weird surface tension patterns
<whitequark>
DocScrutinizer: that was a $25 extra-cheap prototyping (for 10 10x10cm boards)
<whitequark>
everything except the damned solder mask is great
<wpwrak>
whitequark: when that happens, try thin solder wick. (thin: <= 1 mm wide)
<DocScrutinizer>
for my education: I thought solder mask is the even green coating, while silkscreen is the printing (usually white)?
<whitequark>
and the latter is off by ~0.8mm
<whitequark>
argh, that was a typo
<whitequark>
of course the silkscreen is off
<whitequark>
solder mask, holes, vias and every other thing is perfectly done
<wpwrak>
off by 0.8 mm ? nice ;-)
<whitequark>
yeah
<whitequark>
maybe even 1mm, it varies
<wpwrak>
why not just do their own creative painting instead ? ;-)Â Â well, thinking of it, they kinda did :)
<whitequark>
they've also added some internal number on a random place on the board
<whitequark>
I've rechecked: they actually do that for every PCB
<whitequark>
as you can see, the printings inside the top connector aren't on gerbers
<DocScrutinizer>
wpwrak: seems they really do "creative painting" then ;-P
<whitequark>
exactly
<whitequark>
but well then, it's $25 and they did it in single day
<whitequark>
I'll rather scratch off some silkscreen from two boards I do rather, for example, pay twice of that, or wait for a week.
<wpwrak>
and then let's count the hours you spent figuring out what exactly they had done ;)
<wpwrak>
if i need quick but unreliable, i do it in my kitchen :)
<whitequark>
wpwrak: I think that was a meaningful experience. sometimes things go wrong anyway, and it's better to know what the hell may happen there instead of trying to figure it up in a hurry on some much more complex and expensive board
<wpwrak>
yeah. you already know where not to go for complex boards :)
<DocScrutinizer>
wpwrak: you do ds+via in your kitchen? respect!
<whitequark>
DocScrutinizer: ds?
<DocScrutinizer>
doublesided
<wpwrak>
DocScrutinizer: double-sided yes, vias with a bit of wire.
<whitequark>
that's very impressive, yes
<DocScrutinizer>
wired vias suck :-D
<whitequark>
I am barely able to do a 1-sided board with 12mil traces
<wpwrak>
DocScrutinizer: i have a drill and wire combination where the wire stays in place by friction. takes a lot of pain out of the soldering :)
<DocScrutinizer>
hmm
<whitequark>
tried to make them for ~half of a year intermittently, but finally gave up
<whitequark>
it has consumed a whole lot of time with almost no outcome
<wpwrak>
whitequark: maybe you should reconsider your approach to vodka :)
<whitequark>
*facepalm*
<wpwrak>
(-:C
<DocScrutinizer>
wpwrak: I used to use small copper 'nails' which I riveted with a 20g hammer and a bolt then
<wpwrak>
pheew ...
<DocScrutinizer>
final soldering is utterly simple, and almost not needed at all
<whitequark>
wpwrak: anyway, PCBs without any solder mask conflict with my aesthetic feelings
<wpwrak>
same with my wire. i just add solder paste on both sides of the vias, put the wire into the holes, heat, done
<DocScrutinizer>
whitequark: I'd redesign my silkscreen anyway
<DocScrutinizer>
it's too tight
<wpwrak>
i can also do it without solder paste, but it helps in difficult situations
<DocScrutinizer>
silkscreen usually isn't that precise
<whitequark>
DocScrutinizer: you've meant my silkscreen, I guess. or not?
<DocScrutinizer>
yep
<whitequark>
that's Eagle's default silkscreen for most of the components. I think I only designed it for IC2
<DocScrutinizer>
hmm
<whitequark>
(sorry, I'm too stupid to use KiCad or some other FOSS tool)
<DocScrutinizer>
JP1 JP3 and IC1 silkscreen looks errr odd
<whitequark>
ahh yes, also I've made JP2 from scratch, yes
<whitequark>
that's for a very perverted Hirose connector
<whitequark>
the really funny thing is, when I've tried to plug in the LCD, the connectors did not match anyway
<DocScrutinizer>
err is that JP2? I just see JP1 is at the bottom, not next to R3
<DocScrutinizer>
umm JP4
<DocScrutinizer>
JP2 looks not all that bad
<whitequark>
pitch is the same, but my one has "blades" (i.e. flat and wide pins), and the one at LCD _almost_ likes my mating part, but it expects small round pins instead, and a bit different keys
<wpwrak>
yeah, a bit tight. but what really screws it up is the HUGE offset. i don't think the rest would be a problem.
<whitequark>
DocScrutinizer: JP3 and JP4 is from Eagle's pinhead library. I think I'll use SparkFun one in the future, it's quite better IIRC
<whitequark>
*are
<DocScrutinizer>
anyway, why print any silkscreen so close to the soldering area at all? allow silkscreen to move a little, like +-1mm
<wpwrak>
except, of course, the absence of thermal relief. you want to fix that before you make the next 10M units ;-)
<whitequark>
I understand it _now_. But that's my first PCB with silkscreen/solder mask, as the title states
<whitequark>
it's not surprising that I screw it up :D
<DocScrutinizer>
e.g. I'd never ponder to print silkscreen in between adjacent pins of a post-connector
<DocScrutinizer>
and what eagle does there feels kinda odd
<whitequark>
DocScrutinizer: do you add all silkscreen on your boards manually? or only the outlines?
<whitequark>
or do you just design all the components from scratch? :)
<DocScrutinizer>
err, I usually only add component label silkscreens, or if I choose to add frames etc for e.g. smt resistors etc then I make sure they have at least 0.5mm clearance to the solder area
<DocScrutinizer>
it's not exactly unusual for silkscreen printing to be less carefully done than all the other steps of PCB manuf
<DocScrutinizer>
after all silkscreen is not supposed to be any "functional" part of the PCB - it's for mere convenience
<DocScrutinizer>
solder stop mask otoh is usually very accurately done
<DocScrutinizer>
even the paint used has different properties it seems
<whitequark>
I think it's because of different processes, i.e. solder mask is photoresistive too--isn't it?--and silkscreen is done, well, with silkscreen process
<whitequark>
the latter seems much less precise for me
<DocScrutinizer>
yes, exactly
<whitequark>
darn. still does not work :/
<whitequark>
I wonder why
<DocScrutinizer>
that's why for silkscreen there's just one mandatory rule: keep clear of soldering pads ;-D
<whitequark>
10 minutes earlier, EN was effectively isolated by silkscreen. it isn't now...
<whitequark>
ahh of course. it won't work with FB either.
<whitequark>
*without
<whitequark>
its thickness is enough to prevent contact if there's even a small island, less than 0.1x0.1mm
<whitequark>
how do you think, is it enough to place a small (8WSON, it is like a small LGA-8) chip on the pre-tinned (i.e. with a small amount of solder on it) pads and then heat it with hot air and let surface tension do its work
<whitequark>
or should I press it gently on the top to push it to the board?
<wpwrak>
how would you prevent it from getting blown away without pushing a little ?
<whitequark>
hmm
<wpwrak>
and i hit air fails you, you can always fall back to flux + solder + iron
<whitequark>
it doesn't get blown away even on the top air speed of my hot air gun
<wpwrak>
s/hit/hot/
<whitequark>
I use an RMA flux-gel, that may be the cause
<wpwrak>
(not blown away) lucky you :)
<wpwrak>
okay, RMA is very sticky :) but still ...
<whitequark>
it doesn't get at all, really
<whitequark>
never had that problem
<whitequark>
even with 0603 resistors or 3x3mm cases
<whitequark>
it's our special russian hot air :D
<wpwrak>
hmm. maybe your is just better than mine :)
<whitequark>
mmmkay, still does not work.
<whitequark>
I hate my life.
<whitequark>
I guess when it _looks_ like it's a bit off, it is actually not soldered at all.
<wpwrak>
if you can see a problem, there are probably two others already that you don't ;-)
<whitequark>
ok, I've pushed it to the board. looks like _now_ it _is_ soldered
<whitequark>
so I should cool it down and check...
<whitequark>
(the reason behind me not wanting to push the component is that yesterday I've moved it quite far away from the pads. It's better today by some reason.)
<wpwrak>
three spools each of 0.5 kg of solder later ... ;-)
<whitequark>
I don't add more solder, it isn't needed
<wpwrak>
for pushing, what works best for me are angled tweezers
<whitequark>
and I've used almost no flux, maybe several mm's from the syringe
<whitequark>
(tweezers) yep, I'm using them. they're most convenient for this IMO, too
<whitequark>
(on the other hand, these extra-super-small components are fast to heat too, so they _could_ survive more solder-desolder cycles :)
<whitequark>
fuck yeah. IT WORKS!
<whitequark>
now, the other board.
<wpwrak>
congratulations ! :)
<whitequark>
thanks
<whitequark>
at least, now I understand the implications of using a random TI-component-which-has-right-characteristics and not-looking-up-the-case-in-advance.
<whitequark>
it looked _much_ bigger on my notebook's screen.
<DocScrutinizer>
building dummies helps a lot
<whitequark>
DocScrutinizer: do you mean printing the PCB on paper?
<DocScrutinizer>
even if it's only cardboard or paper
<wpwrak>
(it looked bigger) ;-))))
<DocScrutinizer>
nah, dummy of e.g. a 0402 component
<whitequark>
hm
<DocScrutinizer>
I constantly fail to figure how small those critters really are
<wpwrak>
building dummies seems hard. printing is easy. also gives you a feeling. although, on paper it always seems more compact than in real life.
<whitequark>
0402 is slightly less than the distance between tips of my tweezers, so I don't use them
<whitequark>
also, (seriously), it's nowhere to be found in Russia
<whitequark>
i.e. there is one very expensive (and by "very" I mean 10x-50x more expensive than in the right place and/or in something like DigiKey) shop which has them
<DocScrutinizer>
helps for other components as well, esp chips
<wpwrak>
whitequark: you need better tweezers, too :)
<whitequark>
in the places where you can get components by sane price (and I mean radio markets), there are no 0402 ones. 1206, 0805, yes. 0603 -- harder, but still possible. 0402 and less is missing at all. looks like it's not only me having problems with them
<DocScrutinizer>
whitequark: well at real values of a dozen per penny they will need massive increase in price to make any money on selling them
<wpwrak>
0402 isn't too hard. but you can't see very well at that size. so you just have to have faith :)
<DocScrutinizer>
when sold in single qty
<kristianpaul>
feels bad about his soldering equipement
<whitequark>
DocScrutinizer: at market I can buy some regular components (like, for example, 0603 22p ceramics) for ~$0.016 or even less, down to $0.005 if >50 pts
<kristianpaul>
also i dont know how to handle the GPS RF IC, i dont want to damage if i touch it?
<whitequark>
(there are some things like really fat and small ceramics in 0603/uF range, which is still expensive and/or missing, but that's different things)
<whitequark>
and that shop (called Chip & Dip; don't go there if you'll see it) sells them for no less than $0.2 each, regardless of qty
<whitequark>
MAX232 is $10 instead of $1 as it should be, etc.
<kristianpaul>
wpwrak: do you have inventory of your soldering equiment somwheere? ;^)
<whitequark>
also, they frequently fail at selling the right component, as their consultants are quite stupid.
<wpwrak>
kristianpaul: hmm, i'm afraid not. it's a collection from all over the place
<wpwrak>
whitequark: seems that digi-key will get your next order soon :)
<kristianpaul>
what i should get? a 90W iron? twexer of course, flux pen ..
<kristianpaul>
twezers*
<whitequark>
wpwrak: radio market for passive components and terraelectronica for ICs are a really good combination, but they don't have everything. when I'm doing something for myself, I try to pick from the components which are in stock in both, when someone asks me to make a board, I just say that they will finally pay for DigiKey order and shipment :)
<wpwrak>
kristianpaul: a temperature-controlled iron mainly
<whitequark>
(terraelectronica is a company name, of course. they have some _really_ good prices, like selling from qty 1 for the price of 100s)
<kristianpaul>
can i bought that too from digi-key? cause i'm really thinging in make my first big order :)
<kristianpaul>
nv, i can buy that locally i guess :)
<kristianpaul>
what about handling RF ICs, any advice?
<wolfspraul>
good morning
<whitequark>
I'd definitely begin with an antistatic bracelet
<wpwrak>
whitequark: (price from d-k, parts from terra) good idea ;-)
<kristianpaul>
morning
<wolfspraul>
what do you guys think about making an open/copyleft LED driver board?
<wpwrak>
kristianpaul: (soldering iron) you should be able to get this locally. they're not too exotic.
<wolfspraul>
a Chinese friend of mine is working on one and I'm wondering whether I can help him in any way
<wolfspraul>
same as Jon's speakers there't not that much software on it though :-)
<wpwrak>
wolfspraul: what kind of LEDs ?
<kristianpaul>
i need LEDs to iluminate the backyard :)
<whitequark>
wpwrak: hah, I only buy components in d-k when I can't find them in terra. d-k is quite painful to pay and also shipping is _not_ straightforward
<kristianpaul>
or at least i want give a try toe LED tech :)
<wpwrak>
kristianpaul: phew :)
<wpwrak>
kristianpaul: i'd stick with halogen for a few more decades :)
<kristianpaul>
really?
<kristianpaul>
but they got damaged and... oh well
<wolfspraul>
I don't know that much about it, I think 'normal' LEDs?
<wpwrak>
whitequark: well, now you've done d-k once. probably is smoother now.
<wolfspraul>
the board attaches to a package with 70 leds I think
<wolfspraul>
basically it's an intelligent power supply
<wpwrak>
so what do the leds do ?
<wolfspraul>
with an Altera epm570T100 cpld controlling the power supply
<kristianpaul>
display cool 128 x 128 bit images?
<wolfspraul>
illuminate
<wolfspraul>
no
<kristianpaul>
oh
<wolfspraul>
a lamp
<wpwrak>
kristianpaul: halogen is cheap to replace - no matter what the damage is :)
<kristianpaul>
wpwrak: sure ;)
<wolfspraul>
first I will try to get some more data :-)
<wpwrak>
cpld and this kind of circuit sounds a little unusual. i could imagine an mcu with pcm, though
<wolfspraul>
maybe Adam can help him with a small run and we can learn something? don't know yet
<wolfspraul>
no only that cpld, plus LM139 comparator to monitor the output, plus some mosfets
<kristianpaul>
sounds fancy for just a lamp, but i'm curious
<wolfspraul>
he made a prototype board and will show it at a LED fair in guangzhou in a few days
<whitequark>
wpwrak: why not use CPLD if you need a lot of pwm's, but nothing more?
<whitequark>
sounds like a sane choice for me
<DocScrutinizer>
o.O
<whitequark>
I guess it is not :)
<whitequark>
wpwrak: now that the second board works too, I think I've found a flaw in my soldering habit which has caused all this crap
<wpwrak>
whitequark: well yes. if you need lots of fast PWMs :) but an MCU can provide quite a lot of not so fast PWMs via software. LEDs don't need a PWM running at MHz ;-) but perhaps there are requirements we don't know. also, maybe he just likes cplds :)
<wpwrak>
(soldering) heh ! :) experience makes the master
<whitequark>
wpwrak: I'm holding the hot air gun at a small angle, and the component, no matter it's just 1mm high, blocks the air flow to the other side of it, causing it to not solder to the board
<wpwrak>
hmm, i just go around the component with the hot air
<kristianpaul>
wpwrak: do i need a hot air gun or the iron should be okay?
<whitequark>
wpwrak: when I beginned to do the same, the boards suddenly began to work
<wpwrak>
kristianpaul: i've only truly needed hot air once so far, and that was for the atben//atusb crystal
<kristianpaul>
why?
<wpwrak>
whitequark: ;-)
<wpwrak>
kristianpaul: because for all the rest, an iron works, too :)
<whitequark>
wpwrak: how much years/centuries of experience do you have?
<wpwrak>
kristianpaul: the crystal has large pads at the bottom
<kristianpaul>
so heat went away easilly?
<kristianpaul>
wolfspraul: 70w wow !
<whitequark>
wpwrak: how can you solder something with pads underneath the chip like LGA or WSON with an iron if you have a board with a solder mask where you can't heat the traces directly?
<wpwrak>
whitequark: heh, not all that long ;-) must have been around 2005 when i got interested again (i played a bit with electronics as a kid but didn't really get much done)
<wpwrak>
whitequark: WSON has a bit of metal on the side
<kristianpaul>
strugles in getting a bom
<wpwrak>
whitequark: and for DIY, i have no solder mask anyway :)
<whitequark>
wpwrak: indeed it does, but I was unable to solder it with just the metal. I've tried getting a solder blob on the tip of my iron and touching the WSON sides with that blob
<wpwrak>
DocScrutinizer: does "H-bridge" in wolfspraul's spec make any sense to you ?
<wpwrak>
DocScrutinizer: except as a self-destruct mechanism for the LEDs perhaps :)
<kristianpaul>
argh, that .net file is too uglgy to print in raw --
<DocScrutinizer>
what's "wolfg specs"?
<wpwrak>
wolfspraul: even 250 kHz is well within MCU territory :)
<kristianpaul>
wolfspraul, fyi i got two boards from gnss-sdr.ru also some components, now i if get this build i can have a second source of data and compare results easilly ;)
<kristianpaul>
to give you a quick update, i'm currently working on the tracking algorythms for namuru
<kristianpaul>
not big deal? but i need re-enforce my C knowledge a bit :)
<wpwrak>
whitequark: (soldering WSON) hmm. looks similar to QFN to me. they're quite doable. the ones without metal on the side are evil, though
<DocScrutinizer>
wpwrak: hardly
<whitequark>
wpwrak: yeah, it's quite like qfn
<wolfspraul>
[likes cpld] yes he's an IC designer
<wpwrak>
kristianpaul: any response from the DIY GPS guy in the UK ?
<wpwrak>
wolfspraul: that would explain it :)
<DocScrutinizer>
unless they plan to use a cascade multiplier to drive a lot of LEDs in series
<wolfspraul>
I'm sure pretty much everything in electronics can be built in 10 different ways, so?
<kristianpaul>
wpwrak: links most of milkymist, qi-hardware related
<wolfspraul>
the cpld currently uses 242 logic cells, with some more functionality should still stay < 1k, or could be reduced to ca. 100 for a low-cost derivative
<wpwrak>
kristianpaul: oh wow, from tomorrow. he's really ahead of his time :)
<kristianpaul>
hum?
<kristianpaul>
Date: Sat, 15 Oct 2011 09:50:20 +0100
<wpwrak>
kristianpaul: anonymous posted at 2011-10-16 01:34:46
<kristianpaul>
sorry i missed on the pastebin
<wpwrak>
:)
<kristianpaul>
X-Mailer: Microsoft Outlook Express 6.00.2900.59
<kristianpaul>
of that make you happy :)
<kristianpaul>
s/of/if
<wpwrak>
eek
<whitequark>
has just unsoldered that hirose connector back, just for the sake of doing it
<whitequark>
I haven't melted it, yay!
<wolfspraul>
ok I will gather some more info about the led driver board...
<wolfspraul>
if we can open it up, maybe it's worthwhile to help with a little small run
<kristianpaul>
lamps are very wellcome over the world i guess, so worth the try i think
<kristianpaul>
and the battery is a good plus
<wpwrak>
lamps are also still difficult economically. leds are still too expensive.
<DocScrutinizer>
I can't see use for a cpld there, for the one-line dimming etc it's too low level, for controlling the H-bridge it's overkill. Any stupid 4bit or 8bit uC will do just fine
<kristianpaul>
10 + 1 ways ;)
<wpwrak>
yeah :) i'd pick an MCU, too. but then, if you're a hammer, everything looks like a nail, right ? :)
<DocScrutinizer>
you don't need "lots of independent PWM" for controlling an illumination LED array
<wpwrak>
depends on what else the LED array is supposed to do. i wouldn't be surprised if it, say, grew USB at some moment in time, too :)
<DocScrutinizer>
hehe
<DocScrutinizer>
USB and cpld? hardly
<wpwrak>
the usual answer to this is ftdi :)
<wpwrak>
and the rest is a software problem :)
<DocScrutinizer>
the whole thing is mainly just a PSU
<DocScrutinizer>
there's just so much you could possibly innovate in PSU design
<kristianpaul>
energy efficient : 95% ? :)
<DocScrutinizer>
:shrug:
<wpwrak>
a random number
<kristianpaul>
:-|
<DocScrutinizer>
prolly,
<DocScrutinizer>
>>a novel design realized with no radiator<<
<wpwrak>
at least he's engineer enough that he knows it can't be 100% ;-) but the rest sounds more like marketing speek
<DocScrutinizer>
sure, with only as little as 3.5W to dissipate ;-D
<wpwrak>
yeah, particularly that :)
<kristianpaul>
:\
<wpwrak>
naw, "delivered power" 70W. are those LEDs _really_ so efficient ?
<kristianpaul>
is it china, no?
<kristianpaul>
i mean, i wonder what world of kind of LEDs there are
<wpwrak>
agreed. he didn't specify for how long this is suppose to work
<kristianpaul>
he :)
<DocScrutinizer>
wpwrak: I guess that's power TO leds, not OUTPUT power from leds
<wpwrak>
maybe it's an array with 10 cm of metal structure between LEDs. that would work nicely :)
<wolfspraul>
yes
<kristianpaul>
at least during the fair ;-)
<wpwrak>
DocScrutinizer: doesn't really matter - you'll still burn a lot in LED losses :)
<DocScrutinizer>
sure
<wolfspraul>
ok we know little :-)
<DocScrutinizer>
as with any other light emitting technology
<wpwrak>
kristianpaul: is was more thinking in terms of fractions of a second :)
<wolfspraul>
I think conceptually yes, it's just a smart power supply