arm-netbook

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1082 discussions

tablet re-re-design
by Luke Kenneth Casson Leighton 12 Dec '14

12 Dec '14

ok so i tried the new layout... _after_ joining all the tracks up of course... and unnnfortunately the cpu card slot is so far down that the battery is squashed badly at the bottom (long) end and is far too small. so... aaaaaaagh! i have to begin again :) next attempt will be to turn the cpu card round 180 degrees (so it comes out on the right). ah all good fun...

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hannstar LCDs LED backlight circuit
by Luke Kenneth Casson Leighton 10 Dec '14

10 Dec '14

On Tue, Dec 9, 2014 at 8:49 AM, joem <joem(a)martindale-electric.co.uk> wrote: > On Mon, 2014-12-08 at 15:45 +0000, Luke Kenneth Casson Leighton wrote: > >> ... *deep breath*... but.... hold everything, i've never been a great >> fan of the 1024x600 LCD panels > > hmmm... thinks odroid-vu > http://www.hardkernel.com/main/products/prdt_info.php?g_code=G140383714860 > > Miniature HDMI monitor for $120. > I bought one. If there were more of these things around > with variety then lessens need for fixed screen. which reminds me: i need to work out a circuit for driving the LCD backlight. does anyone have e.g. one of these: http://www.adafruit.com/products/1931 i need an example circuit to work from: the one that i have uses the SY7201 and it is designed to pulse the LEDs, whereas the Hannstar LCDs have their own dedicated LED backlight PWM input. l.

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Why EOMA68 will advance both free software and free hardware « Nico Rikken
by Alexander Stephen Thomas Ross 09 Dec '14

09 Dec '14

http://nicorikken.eu/blog/why-eoma68-will-advance-both-free-software-and-fr…

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flying squirrel tablet
by Luke Kenneth Casson Leighton 07 Dec '14

07 Dec '14

time for a bit of a rant :) i've been working on the tablet PCB now for... literally months over the past year or more, and i can't quite believe that every time i look at it i find something - yet another thing - that needs fixing or improving. the latest was noticing that NMI# from the tablet's AXP209 wasn't connected to one of the EINTs on the EOMA68 connector, and noticing that 18-pin RGB/TTL with the 8.9in LCD (only 3 lane LVDS) is incompatible with 24-pin RGB/TTL of the 7in LCD (4 lane LVDS). so, goodbye all the resistors for selecting different panels, and then i noticed that the power tracks were crossing the LVDS lines so had to completely reorganise those. i also noticed that the SD/MMC needed moving upwards a bit (so that SDcards could be poked into the case and actually... y'know... lock?), and... ... well, it's just a heck of a lot of detailed work and i'm just... amazed that there's so much to do! oh - one other hilarious thing: i tracked down a company that makes a TI SN75LVDS83b.... the name is *not* texas instruments, it's novatek :) it's the NT7181 and it's literally identical. even the ability to switch TTL levels so that it's 1.8, 2.5 and 3.3v TTL compatible depending on input voltage. anyway it's kiinda fun... l.

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flying squirrel rev 3.1
by Luke Kenneth Casson Leighton 04 Dec '14

04 Dec '14

http://rhombus-tech.net/community_ideas/kde_tablet/news/ so with the micro-desktop and eoma68-a20 underway i'm refining and updating other PCBs such as the flying squirrel PCB and the eoma68-jz4775. the 2nd revision ic3128 PCB should have gone for PCB printing already and assembly in about a week or so's time. just as a reminder i've designed the flying squirrel PCB to accept not one but two LCD panels: the 8.9in 1024x768 LG screen and the 7in 1024x600. l.

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Debian boots in 0.87 seconds
by joem 03 Dec '14

03 Dec '14

Debian boots in 0.87 seconds: http://linuxgizmos.com/headless-arm9-sbc-boots-linux-in-less-than-one-secon… http://www.embeddedarm.com/products/board-detail.php?product=TS-7250-V2 Good if this could be force marched to happen EOMA / Allwinner CPU. A complete world game changer and a lot of funds will get released for dormant projects that need fast boot + linux. Crowd funding world would go beserk :)

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http://rhombus-tech.net/icubecorp/IC1T/news/
by Luke Kenneth Casson Leighton 28 Nov '14

28 Nov '14

ok so lots has happened in the past couple of weeks, firstly thanks to christopher for doing some concept drawings on the micro-desktop dock. turns out that we may have to try something slightly different in order to keep the cost down, chris. we got a prototype back (in MDF laminates), i have some ideas on how it looked and assembled, so i will wait to see what the reaction is, there. the case is what we are waiting for to start the campaign btw. and yes, i really really want it to be wood not plastic. second thing i have been playing with the EOMA68-IC3128 CPU Card - everything works *except* the LAN9514 USB-Ethernet Hub. there are a number of issues, most likely related to unstable power but possibly due to unstable kernel code, and it's simply impossible to tell properly which. so i made a decision to replace the USB-Eth Hub with a GL850G Hub and an MCS7832, because ICubeCorp have tested that combination and we know it properly works. space is *very* tight so it is a bit of a mess. so the revision 1.2 has been done, it now needs review, and then it can go for assembly which is great. i'm not going to push things, so if it's ready when the crowdfunding campaign starts great, if not that's fine we do another campaign separately. also just so people know, one thing we may try is to push the IC3128 to 440mhz (remember it's quad-core so a total of 1.76 ghz of processing power instead of 1.6 ghz), and, also, the whole CPU Card uses only 2.5 watts at 400mhz, which is pretty good for a 55nm SoC. so it is well within the 3.5w margin set for ensuring that no fans or special cooling is needed. l.

3 4

The Hexayurt Project: Free Hardware housing for the world
by Alexander Stephen Thomas Ross 25 Nov '14

25 Nov '14

heres a surprisingly related talk: don't get caught on the title. lots of food for thought for this project. http://files.howtolivewiki.com/d3-t1-03-20130802-1300-one_network_one_world… from: http://hexayurt.com/

2 2

Talk - Eben Moglen - Free and Open Software: Paradigm for a New Intellectual Commons
by Alexander Stephen Thomas Ross 17 Nov '14

17 Nov '14

https://www.youtube.com/watch?v=tbcy_ZxXLl8&html5=1 I felt this was quite relevant.

2 1

IC3128 1280x800 60fps confirmed
by Luke Kenneth Casson Leighton 11 Nov '14

11 Nov '14

http://rhombus-tech.net/icubecorp/IC1T/news/ ok, it's kinda cheating, as it's only 8 bits per pixel, but i managed to get a stable image at 1280x800 resolution, 60fps, on the micro-desktop base. yet to be determined is what's actually the limiting factor - i'm working with ICubeCorp to find out - it's either that the DDR3x16 RAM IC (which is actually a 1600mhz samsung x16 DDR3 chip) is being clocked at only 266mhz or that there is an internal bus which can't get memory fast enough when reading the current scan line/pixel at the framebuffer's memory.location.. all kinda fascinating. what i am speculating is that this 55nm chip could actually be run much faster than the reported 400mhz speed. a processor in 55nm theoretically should be able to achieve 600mhz comfortably, possibly even 800 and maybe 900 with a bit of luck. however that's a huge jump in power requirements and i don't think the power in (pins) have been designed to cope with that. so... we shall see :) l.

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