07:57 <luis_> hola gente

08:08 <pabs3> huh, tuxbrain closing their shop

10:04 <viric> oh

12:45 <wolfspraul> yes, tuxbrain was one amazing guy to buy stuff from, now it's in distributor heaven :-)

12:46 <wolfspraul> http://www.tuxbrain.com/en/content/we-are-fulminating-stock-cheap-cheap-aka-tuxbrains-reborn

12:49 <kristianpaul> oh

12:50 <valhalla> this is sad indeed

13:14 <wpwrak> he was on #qi-hw a few days ago saying that he had good news, but never said what. so maybe he's not so sad about what he's doing.

13:15 <kristianpaul> he mention word reborn

13:16 <wpwrak> yeah. also, i think running a shop is 99% terribly boring work. better to focus more on what's actually fun.

13:16 <kristianpaul> boring and full of details and customer support :)

13:19 <wolfspraul> does anybody know the state of migen actually?

13:19 <wolfspraul> I should ask in #milkymist of course but it feels stressful sometimes :-)

13:19 <wolfspraul> I hope we can switch to it and it's really superior, who knows. maybe another few months?

13:19 <wolfspraul> don't know

13:19 <kristianpaul> i just see uart and ethernet cores

13:20 <kristianpaul> havent tried sinthesize it yet..

13:20 <wolfspraul> hmm

13:20 <wolfspraul> make that 6 months

13:20 <wolfspraul> :-)

13:20 <wolfspraul> kristianpaul: will the m1-gps-expansion board fit on rc3 as well?

13:21 <kristianpaul> sebastien pasted something about ddr but i dint look like a speed test or such

13:21 <wolfspraul> maybe we can go ahead and just make some of them, once I have my diy process figured out I need some jobs...

13:21 <kristianpaul> sure may be no fit, but can be adapted

13:21 <wolfspraul> yeah. in the schematics it shouldn't matter much

13:22 <kristianpaul> current layout isnt friendlier either for rc2 :)

13:22 <wolfspraul> do you think you can bring them to a 'kind of complete' state at some point?

13:22 <wolfspraul> I'm not following it closely

13:22 <kristianpaul> i havent touched layout yet

13:23 <kristianpaul> and after the cut off it should work yes i just removed the fgpa and cypress tranceiver we dont need

13:25 <kristianpaul> once sch is finished i'll move to bom

13:26 <wolfspraul> yes great

13:26 <kristianpaul> wolfspraul: current design dont fit, it need wires

13:27 <wolfspraul> I think my first board targets will be something like atben clone, combine small xc6slx9 with atrf to configure over RF, m1-gps-expansion board

13:27 <wolfspraul> stuff like that

13:27 <kristianpaul> maxim ic is very similar to the avr chip used in atben

13:27 <wolfspraul> and sure maybe it's too ambitious. then I try to light an LED with a series resistor instead :-)

13:27 <kristianpaul> ;-)

13:28 <wolfspraul> worst case I just press the wall button here to turn on my desk light, if all else fails that needs to give me some confidence about my mastership of *electronics*

13:28 <wolfspraul> from there to the ghz circuit should only be a small step

13:32 <kristianpaul> how etching the PCB went finally? i lost track of the thread

13:35 <kristianpaul> i tried that two weeks ago, wpwrak etching solution is powerfull, so match than some errors on the tonner transfer ended "eating" all coper

13:35 <wpwrak> ;-)))

13:35 <wpwrak> maybe your peroxide was a bit too strong

13:35 <kristianpaul> match/much

13:36 <kristianpaul> i need improve that tonner transfer

13:36 <kristianpaul> afaik i dont used that hp paper, instead re-used sheets from a local magazine

13:37 <kristianpaul> may be the pcb wast clean enought.. i dont know

13:37 <wpwrak> e.g., if you use 30% peroxide, it'll etch your board clean in about half a minute. that's an quite exothermic reaction, too. so after a little while, the acid starts to boil and fume. so patience is advised :)

13:38 <kristianpaul> do you use a cloth iron for transfer right?

13:38 <wpwrak> i use a "plastificadora"

13:38 <wolfspraul> I haven't started yet, too many other issues. I will take the next step starting from mid next week, together with xiangfu probably

13:39 <kristianpaul> oh

13:39 <wolfspraul> but 100% on track for this, definitely

13:39 <wpwrak> but a clothes iron would do, too. it's just less reliable than the machine.

13:39 <kristianpaul> thats fancy :)

13:39 <kristianpaul> less reliable indeed..

13:39 <kristianpaul> is the only tool i dislike from this process, i dont feel confident with it

13:40 <wpwrak> (less reliable because it's a manual process. some people are great at it, though. ironically, women tend to be very good at handling toner transfer with an iron. they produce better results than my little machine. maybe there's something right about those stereotypes :)

13:42 <wpwrak> wolfspraul: the first experiment should be a test of the acid. no circuit, just a snippet of the pcb. see how it works.

13:42 <kristianpaul> that is fun :-)

13:43 <wpwrak> wolfspraul: you can add some patterns with a water-resistant pen, too. that will allow you to find a pen that provides a reliable cover, to repair flaws in the toner transfer.

13:44 <wolfspraul> sure, joerg mentioned that already

13:44 <wolfspraul> saved in brain

13:44 <wolfspraul> of course I will experiment, I am quite confident that after a few days this is sorted out

13:44 <kristianpaul> wpwrak: ok, so you just put together the PCB and printed layout and let the "plastificador" do its job?

13:45 <wolfspraul> the main difficulty seems to be the toner transfer, that sounds like it has some unknown variables inside

13:45 <wolfspraul> but I'm not worried

13:45 <wpwrak> kristianpaul: if you acid is too aggressive (e.g., if the etching finishes in less than, say, 5 minutes), you can add a bit of demineralized/distilled water to dilute it, which slows it down

13:45 <wpwrak> s/you ac/your ac

13:45 <qi-bot> wpwrak meant: "kristianpaul: if your acid is too aggressive (e.g., if the etching finishes in less than, say, 5 minutes), you can add a bit of demineralized/distilled water to dilute it, which slows it down"

13:45 <kristianpaul> get a plastificadora, it seems make it more easilly and confortable to use

13:45 <kristianpaul> wpwrak: yup i took 3 minutes..

13:45 <kristianpaul> s/i/it

13:45 <qi-bot> kristianpaul meant: "wpwrak: yup it took 3 mitnutes.."

13:46 <wpwrak> kristianpaul: you need to modify the plastificadora. 1) they usually don't allow passage of such thick material and 2) they're too fast

13:47 <wolfspraul> ah distilled water, good idea to get in advance

13:47 <wpwrak> wolfspraul: the key to successful toner transfer is finding a good paper. expect to spend some time with that. that hp paper is perfect but may be hard to find.

13:48 <wolfspraul> for the toner transfer, I would feel better if it were a better understood chemical thing

13:48 <wolfspraul> sure, I know [hp paper]

13:48 <wolfspraul> just what is 'better' and why do some work and some not so well and some not at all

13:48 <wolfspraul> but ok, no problem

13:48 <wolfspraul> I will try with a variety of papers and something will work

13:48 <wpwrak> demineralized water should be available at any place that has stuff for cars. just make sure it has no additives (anti-corrosive, anti-freeze, whatever)

13:50 <kristianpaul> hmm

13:51 <wpwrak> "better" fewer flaws. flaws come in many shapes: can be that traces "blur" (-> too hot). can be that the toner doesn't stick to the pcb (so some thing come off when you remove the paper; usually a sign of insufficient heat/pressure, but can also paper chemistry). can be that there are holes/gaps inside of toner regions (-> usually a sign of outgassing)

13:54 <wpwrak> it's imperative to do a careful visual check of the board after toner transfer. you can fix small issues manually. e.g., if a trace is broken or looks too weak, you can fix this with the water-resistant pen. if toner has blurred into an adjacent pattern, you can scratch off the toner with tweezers / knife / etc.

13:54 <wolfspraul> are there flat laser printers where you can just pull a thin pcb right through it?

13:55 <wolfspraul> or if a transfer is needed, maybe we can transfer via some other material that works more reliably and is still easy to source?

13:56 <wolfspraul> for example I could go through the variety of kitchen papers and foils, some of them have amazing characteristics and easily available

13:59 <wpwrak> a very thin pcb, maybe. but most likely, they need to change the drum after a very small number of runs. so that might be a bit expensive.

14:00 <wpwrak> alternative papers are possible, yes. you just need to experiment a bit.

14:02 <wpwrak> (change the drum) because i would expect it to get scratched. but i'm too coward to try that :)

14:03 <wpwrak> your printer's specification should provide a hint of what thickness of materials it can handle in general

17:14 <qi-bot> [commit] Werner Almesberger: add floor() function (master) http://qi-hw.com/p/fped/9a6c7d2

19:45 <qwebirc89599> h