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Re: [Arm-netbook] [flying squirrel] TODO list
by luke.leighton 04 Oct '13

04 Oct '13

well.... uh... it looks like i totally cocked up the ADC side of the flying squirrel circuit for the microphone! i must have been on drugs or something (someone slipped something into my hot water with a bit of milk). the connections i made to the LM13700 OTA bear absolutely no relation to the example schematics! luckily i did manage to connect +ve and -ve to the right pins, meaning that the 3 LM13700s i now have are absolutely fine, so i've spent the day putting resistors on one of them like a porcupine, experimenting. what's really awesome about the LM13700 is that it has a fascinating history of its own: http://www.idea2ic.com/LM13600/LM13700.html being an independent-buffered dual-version of an incredibly famous OTA - the CA3080 - which was first sold in *1969* http://www.till.com/blog/archives/2005/06/last_of_the_ota.html i'm reminded of when i put the flying squirrel schematics in front of a chinese ODM for them to quote helping get it made, they said "that's a really old school design". i had no idea :) anyway, i'm presently flipping quills on an LM13700 porcupine and also i'll errr... this time be actually... like... connecting the ADC VREF pins on the STM32F so that... y'know... the ADC actually works? honestly... :) l.

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Re: [Arm-netbook] [flying squirrel] TODO list
by luke.leighton 02 Oct '13

02 Oct '13

On Thu, Sep 26, 2013 at 11:16 AM, luke.leighton <luke.leighton(a)gmail.com> wrote: > * find out why the AXP209 is randomly shutting off (could be floating reset?) *sigh* this turns out to be because (AGAIN) wits-tech did not... AGAIN ... tell us that they'd made changes which were NOT authorised, to the EOMA68-A20 CPU Card schematics. this time what they've done is wire the 5V (ACIN) directly to the USB-OTG line of the AXP209. *deep breath*.... the consequences of that are that when the device is being powered by USB-OTG, 5V appears on the EOMA68 5V power lines. the consequences of _that_ are that the flying squirrel I/O board (which has its own AXP209 and a 5V step-up regulator to turn IPSOUT into a stable 5.0V output) fights with the incoming 5V power... and loses the moment that the voltage fluctuates by even the smallest amount (such as the A20 doing anything resembling the slightest amount of processing). if wits-tech had fucking well told me what they were doing i could have put in a MOSFET or other power regulator on the I/O board to cope with power-in as well as power-out. not entirely sure what to do here, i'll have to think about it. as far as testing the flying squirrel is concerned i can get it working (in a rather painful laborious way) by disconnecting USB-OTG: i've verified that the CPU Card can in fact be powered by *incoming* 5V power from the I/O board... i might need to cut one of the micro-usb cables i have here and remove its 5V line or something. l.

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[EOMA68] changes to I2C EEPROM address location
by luke.leighton 02 Oct '13

02 Oct '13

http://elinux.org/Embedded_Open_Modular_Architecture/EOMA-68#Requirements_f… i've updated the specification to reflect what's actually been deployed on the flying squirrel pcb. apologies but i'd read the AT24C64 datasheet incorrectly: the "1" in the 8-bit MSB of an I2C address is not counted in the address so i'd read it as "0xA2" when it should be "0x51". apologies but all boards currently being designed will need to update schematics to match accordingly. l.

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Ubuntu 13.04 Desktop Linux now running on EOMA68-A20
by joem 01 Oct '13

01 Oct '13

Ubuntu 13.04 now running on EOMA68-A20 Sata disk images and how to's here: http://www.gplsquared.com/eoma_boot/eoma_boot.html#Ubuntu_13_04 (The same image can work on Cubieboard2 as well with some minor tweeks.) The EOMA now functions like a powerful arm-netbook desktop computer and as powerful as any netbooks that first came out. Probably under $50 BOM costs for a netbook like ARM PC box with say an upgradeable 16GB sata SSD built into the box. This release has Gambas3 compiled and working. Gambas allows rapid GUI application development. So - now very easy to customize EOMA to become IoT gadget with a GUI user interface, a web interface or both.

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Re: [Arm-netbook] ARM system with good wifi
by luke.leighton 01 Oct '13

01 Oct '13

On Fri, Sep 20, 2013 at 4:04 PM, Stefan Monnier <monnier(a)iro.umontreal.ca> wrote: > The lack of other answers makes me suspect that all the builtin wifi > adapters on ARM systems just suck, IOW what I'm looking for > doesn't exist. there are two factors at play here. 1) the price-war on tablets is driving everything down. if you're putting in a high-quality $5 WIFI module you just made the entire product uncompetitive because everyone else is using $2 modules. when the product BOM is only $30 the higher-quality WIFI module represents a whopping 10% increase in the BOM. 2) low-end portable products need lower-power WIFI modules otherwise the battery has to be larger, and *again* that pushes up the price to uncompetitive levels. low-power WIFI modules tend to have shit-for-brains range the only other thing i can think of perhaps is for you to take some pictures of the wifi module, identify it, and then hunt around to see if there's a way for example to add an external antenna (or a better external antenna if it already has one). then make sure it's installed in a place that's away from any metallic objects inside the casework. the only problem with increasing the effectiveness of the antenna is that it can suck more power out of the module's R.F. transmitter (i don't fully understand this but it's what i've heard so i'm repeating it parrot-fashion). so you'll just have to watch out for that, ok? l.

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AC to DC power adapter with multiple outputs
by Arokux X 30 Sep '13

30 Sep '13

Hi all, I am probably once again asking for something that is not there, but anyway. I'm currently hacking on several single board computers. Each of them requires 12V. So I would need an AC to DC power adapter for each. Each of adapters will require a separate socket in my master plug. What I would like to have is _one_ AC to DC adapter with multiple outputs to which I then connect my boards. Basically something like a USB hub but for power supply. After much of googling I wasn't able to find something like this. Have I missed something? Thanks, Arokux

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Re: [Arm-netbook] Home microserver based on ARM
by mike.valk＠gmail.com 30 Sep '13

30 Sep '13

2013/9/27 Stefan Monnier <monnier(a)iro.umontreal.ca> > >> But to use something like the quattro docking station, either you have > >> to use a USB connection (rather undesirable, especially since all those > >> ARM thingies seem to be limited to USB-2.0 so far), or you have to use > >> a SATA connection where the controller supports "port multiplier". > > Both types support sata multiplier. > > I lost you: both types of what? Both the i.MX6 and the A10/A20 SoCs? > You lost me twice. There Are two CuBox modules now: 1st CuBox/CuBox Pro. Which Has the Marvell Armada. http://www.solid-run.com/mw/index.php?title=CuBox_hardware_specification 2nd CuBox-I. Which comes in the four flavors of i-MX. http://imx.solid-run.com/wiki/index.php?title=CuBox-i_Hardware Unfortunately they don't have a Allwinner A10/A20 version. There HW design is quite good and sw hacker frendly. Eg. built-in USB->UART chip. > > > Just read that the original CuBox does it better. The Marvell armada one. > > That is. > > It seems that the Inc doesn't support asynchronous transfer. > > Are you saying that the Armada chip only supports the "command based > switching" (so only one drive can be active at a time), whereas the > i.MX6 (used in CuBox) supports "FIS–based switching" (commands can be > sent to drives regardless if other drives still haven't finished > processing previous commands)? > Just the opposite: 1st: Marvell Armada -> FIS Based switching 2nd: i-MX -> Command based switching http://www.solid-run.com/phpbb/viewtopic.php?p=8001&sid=c661b1aaed86bc1a510… (posted by Rabeeh; The company's founder/CTO) > > > Stefan > > > _______________________________________________ > arm-netbook mailing list arm-netbook(a)lists.phcomp.co.uk > http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook > Send large attachments to arm-netbook(a)files.phcomp.co.uk >

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Re: [Arm-netbook] ARM system with good wifi
by mike.valk＠gmail.com 30 Sep '13

30 Sep '13

2013/9/19 Stefan Monnier <monnier(a)iro.umontreal.ca> > I'd like to use something like a Mele-A2000 (i.e. one of those > cheapish-but-beefier-than-linksys-router ARM systems) as access point, > but my Mele-A2000 has a pretty weak wifi. Part of the problem is the > wifi driver I suspect, but other things like the antenna are probably > not helping. > > Does anyone have a product to recommend, based on something comparable > to an Allwinner SoC, but where the wifi is of good quality? > Dunno if it actually works, but A20/A10 with an external antenna: https://www.miniand.com/products/Mini%C2%A0Xplus%20TV%20Box%20H34 https://www.miniand.com/products/Mini%C2%A0Xplus%20TV%20Box%20H24 > > > Stefan > > > _______________________________________________ > arm-netbook mailing list arm-netbook(a)lists.phcomp.co.uk > http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook > Send large attachments to arm-netbook(a)files.phcomp.co.uk >

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Re: [Arm-netbook] AC to DC power adapter with multiple outputs
by Benson Mitchell 30 Sep '13

30 Sep '13

On Sep 29, 2013 9:50 AM, "Dr. David Alan Gilbert" <dave(a)treblig.org> wrote: > Have you tried a normal PC power supply; I think there is a way to fudge > them to believe a motherboard is connected. That's the ticket. But there is one gotcha with this -- some PSUs won't operate or don't operate well with no or very low load (they need like 1-5% of rated current, minimum). So check the voltages with no load, if all seems well, good! otherwise, throw a 12V light bulb on the output and that should make it behave. Benson

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Re: [Arm-netbook] [flying squirrel] TODO list
by luke.leighton 29 Sep '13

29 Sep '13

argargargh, the USB is connected the wrong way round to the STM32F. arghargargh :) so i have to carefully pull up 2 legs of the STM32F then solder flying leads underneath them.... *gibber*

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