Re: Ambient light sensing via LED response

2009-05-06 Thread NoiseEHC

 But why do you say you would need 1 mV accuracy ?   Bright sunlight  
 is far stronger than
 the light sources he used.
   
I am not an engineer so forgive me if I am saying something stupid, but 
is not the goal to switch off the backlight if and only if there is no 
difference between the switched on and switched off state? I mean that 
this implies that you have to measure the mV at a light level when you 
cannot see the difference (what can be a much fainter light than the sun).
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Creating a Puritan Howto for Ubuntu (8.10)

2009-05-06 Thread Mike Dawson
Dear All,

After surveying the tools that we have available for creating custom
OLPC builds which seems to be a menu of NAND Customizer, Pilgrim, or
Puritan Puritan looks like being the way forward for us as we have not
yet invested much time / effort in other tools (we run a shell script
customizer on the first laptops we put out),

Puritan seems to have better support for Ubuntu (when we tried Pilgrim
before we gave up on Ubuntu, ran it in a Fedora VM, then on our
bandwidth had to run on a Fedora VM on a remote server in Germany),
and the principles behind it look like meeting the challenges we face.
 What I really like is caching - that is unbelievably important.
Squid does not do a good job of caching repos etc. and the only way
before we did that was running Polipo to cache every single HTTP
request mindlessly.

1. On applying the patch to mock - Not quite sure how that is done
here as the mock package through apt is compiled in binary.  We tried
apt-get source mock and then grep for the strings which are in the
patch; but it has:

PKGPYTHONDIR = os.path.join(os.path.dirname(os.path.realpath(sys.argv[0])),
mock)
not
PKGPYTHONDIR=/var/lib/python-support/python2.4/mock (as specified by
the patch referenced at http://wiki.laptop.org/go/Puritan - Ubuntu
section

Which makes mock.patch fail.

What is the recommended way of dealing with this?  Can we make an
official debian format patch for this package or maybe setup a PPA?

2. Are there any specific instructions for ensuring that caching is
enabled?  Couldn't find that on the wiki at the moment...

3. I would like to make a more step by step kind of Wiki page for new
deployments such as ourselves here in Afghanistan - I have started at
http://wiki.laptop.org/go/Puritan/StepByStep - hopefully we can go
through the whole thing tested against a regular Ubuntu 8.10 install
so that we have something for deployments to quickly and easilyget
going with making custom images.

Thanks,

-Mike
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Re: Battery recovery issues

2009-05-06 Thread Emiliano Pastorino
Here's the logfile.

Just one observation: it tooked me 3:30 h to discharge the battery (I did a
bat-recover for 16 hours previously),
so the battery seems to be in good shape, and also the XO, since with other
batteries the led and output from
all these commands behave as expected.

Also, I want you to know that the first 20 batteries I tested weren't
faulty, they just needed to be charged
(trickle charged at the begining, then normal charged). I think that kids
and our technicians don't know what
does the 4-times-blinking-orange-led mean, so I'm giving them immediate
instructions on how to proceed.



On Tue, May 5, 2009 at 6:44 PM, Richard A. Smith rich...@laptop.org wrote:

 Emiliano Pastorino wrote:

  bat-charge reports this: 320.83 mAh (7d53) 1428.12 mA (2ddc) 6.492 V
 (195c) Chg: 0.41mAh (  29) then every column raises line to line (I
 copied that by hand because


  bat-charge-log always says Can't open file, even when usb stick is
 plugged in.


 Turns out the way I did the disk devices won't work unless you either:

 1) boot with a usb drive plugged in
 2) run 'p2' before bat-debug-log

 'p2' will re-probe usb devices.

  If the first column is battery's charge, then it's almost dry. Should
 I try bat-recover or charge it the usual way?


 The first column is the ACR reading and you can't tell anything by just
 1 reading.  You have to know what it was when you started discharging or
 charging.  I don't report SOC in that listing cause generally I don't care.
  I want to know what it does after I turn on charge rather than what level
 it was at previously.

 bat-charge simply enables charging and then starts reading the battery
 directly.  Thus it does not care about any of the settings in the EEPROM.
  Its a good diag tool to see if the battery just physically won't take
 charge or if you just can't communicate to it at all.  If bat-charge works
 but normal charging does not then its EC or EEPROM badness.  The LFP
 batteries have an overvoltage cutoff that will protect them so its ok to
 just turn one on and leave it.  For NiMH you would end up reducing its life.
  But since you don't have any NiMH you don't care.

 'bat-recover' works by PWMing the charge pin to keep the charge current
 very low and allow the cells to equalize yet not trip the over voltage like
 they would if you just turned on the charge and left it.  The settings I've
 picked by default seem to work in most cases but I've had many batteries
 where I needed to reduce the current even further from the default settings.

 To speed up the process you can use normal charging methods to get the
 battery close to full (or wherever it cuts out at)  That way the recover
 process will be much shorter.

  I'll try bat-recover with a bunch of batteries today, so maybe
 tomorrow or on Wednesday I'll be sending you some logs, if it is ok
 to you.


 After looking at your bat-debug log I've realize that the extra diagnostic
 info is only present in f-series firmwares with my newer EC code.

 I'm forwarding you an e-mail with a copy of q2f02 that I worked on while
 trying to solve some problems with batteries in another deployment.

 q2f02 will be behind q2e41 in terms of OFW but has EC code with extra
 battery diag info.  For battery testing there should no difference between
 the 2.

 Its also available here: (Just never announced since a new e-series release
 happened right after)

 http://dev.laptop.org/pub/firmware/q2f02/

 So install f02 on your test laptop and re-run bat-debug-log after you have
 first run 'p2' and the logging to disk should work.  I don't need any more
 see-bstate info.

 so the steps:

 install f02
 remove battery
 boot
 stop at ok
 insert usb drive (or boot with it inserted)
 run 'p2'
 run 'bat-debug-log'
 insert battery
 run for a couple of minutes then hit a key
 send me the log.

 I'll try to get a f03 out soon with the latest of everything but I've got
 gen 1.5 bring up tasks that I need to attend to.


 --
 Richard Smith  rich...@laptop.org
 One Laptop Per Child




-- 
Ing. Emiliano Pastorino
LATU - Plan Ceibal
Av. Italia 6201 CP: 11500, Montevideo, Uruguay
Tel: (598 2) 601 5773 int.: 213
2:29 0 0x0 0x0 0x1 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:29 0 0x0 0x0 0x0 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:30 0 0x0 0x0 0x0 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:30 0 0x0 0x0 0x0 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:31 0 0x0 0x0 0x1 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:31 0 0x0 0x0 0x1 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:32 0 0x0 0x0 0x0 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:33 0 0x0 0x0 0x0 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:33 0 0x0 0x0 0x1 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:34 0 0x0 0x0 0x1 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:34 0 0x0 0x0 0x0 0x1 0x0 0x0 0x0 0x0 0x0 0.00 0.000 0.00 0.00 0 0x0 0x0 
2:35 0 0x0 

Re: [Server-devel] backup : problem opening /library/users/XXXX/datastore-xxxxx/store

2009-05-06 Thread Martin Langhoff
On Tue, May 5, 2009 at 4:52 PM, Martin Langhoff
martin.langh...@gmail.com wrote:
 Let's keep this on the list. Is that from a recent SoaS? The datastore
 storage format has changed then, and we need to add support to Moodle
 for it.

 More work! :-p

Done - not tested much -- the zipfile you've given me didn't have much data.
http://dev.laptop.org/git/users/martin/moodle.git/commit/?h=mdl19-xsid=5f522dbef1878284d15ae2ef0872c8dd5caa1953

So I need your help in reporting whether it works well for your SoaS
clients. I assume you're already using my moodle branch, so a mere git
pull will get you the right code... ;-)

Note: It won't list metadata-only entries. If there's no 'data'
file, it's not listed.

cheers,


m
-- 
 martin.langh...@gmail.com
 mar...@laptop.org -- School Server Architect
 - ask interesting questions
 - don't get distracted with shiny stuff  - working code first
 - http://wiki.laptop.org/go/User:Martinlanghoff
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Re: plz test Build 802 + Firmware Q2E41 = Candidate Release 8.2.1

2009-05-06 Thread Sayamindu Dasgupta
On Thu, Apr 30, 2009 at 5:41 AM, Holt h...@laptop.org wrote:
 The build is now signed so you don't even need a developer key:
 http://wiki.laptop.org/go/Friends_in_testing

 Helping us test WPA (WPA2 especially) would be most useful, since these
 wifi connections sometimes fail as much as 20% of the time, when Release
 8.2.0 seemed to fail only ~10% of the time.  And of course try:
 http://wiki.laptop.org/go/1_hour_smoke_test

 Please help us clean up Release Notes on the way!
 http://wiki.laptop.org/go/Release_notes/8.2.1

 Recap -- all you should need are these 2 files burned onto a USB stick:
 http://download.laptop.org/xo-1/os/candidate/802/jffs2/os802.img (233MB)
 http://download.laptop.org/xo-1/os/candidate/802/jffs2/fs.zip (155K)

 Follow the usual procedure (http://wiki.laptop.org/go/USB_update), grab
 Activities from your XO's Control Panel later, and Buzz (IRC Live Chat)
 if you get stuck: http://forum.laptop.org/chat

 Thanks!

In case it is useful, I used 802 on a B4 and a MP to develop and test
file sharing for the ImageViewer activity and FBReader activity. Did
not see any problems. (I was connected over a unsecured Linksys
WRT600N AP (with MAC filtering)).

Thanks,
Sayamindu




-- 
Sayamindu Dasgupta
[http://sayamindu.randomink.org/ramblings]
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Re: Battery recovery issues

2009-05-06 Thread Richard A. Smith
Emiliano Pastorino wrote:

 Also, I want you to know that the first 20 batteries I tested weren't 
 faulty, they just needed to be charged
 (trickle charged at the begining, then normal charged). I think that 
 kids and our technicians don't know what
 does the 4-times-blinking-orange-led mean, so I'm giving them immediate 
 instructions on how to proceed.

It means its in trickle charge but that only happens with newer firmware.

-- 
Richard Smith  rich...@laptop.org
One Laptop Per Child
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[Fwd: Re: Ambient light sensing via LED response]

2009-05-06 Thread Reinder de Haan


 Original Message 
Subject: Re: Ambient light sensing via LED response
Date: Thu, 07 May 2009 00:02:49 +0200
From: Reinder de Haan r...@mveas.com
To: raf...@laptop.org
References: 200904290017.n3t0hl2v006...@new.toad.com
c5d4a4e5-b183-4b7d-bafb-3488e15f7...@laptop.org
c6d9bea0905011128j2d5cdf3cw975cfad790480...@mail.gmail.com
675d3c5c-95ed-4ee9-84bc-3b5164675...@laptop.org
c6d9bea0905042207i458ed9b1if74e0e16d24f5...@mail.gmail.com
4a00a073.8020...@mveas.com
a80d16920905051544s525b7039nf7e87a4a3c754...@mail.gmail.com
75dc0458-925b-4792-9aee-a24b9b1f3...@laptop.org
a80d16920905051952h3d82d15brb8f690cf1c402...@mail.gmail.com



Rafael Enrique Ortiz Guerrero wrote:
  
 
 
 On Tue, May 5, 2009 at 8:34 PM, John Watlington w...@laptop.org
 mailto:w...@laptop.org wrote:
 
 
 On May 5, 2009, at 6:44 PM, Rafael Enrique Ortiz Guerrero wrote:
 
 These measurements are really cool.
 
 But the question remains in whether the ADC could have a
 resolution of 1mv?, i mean in light of these measurements is
 necessary to have an ADC that can reliable sense these
 variations and then with that basis  have a transfer function
 and add it to the algorithm.
 
 
 Absolutely not.  The A/D is eight bits, with an input range spanning
 0 - 3.3V, so the best you
 can hope for is about 13 mV per LSB.  I would guess actual accuracy
 to be closer to 26 mV. 
 
 
 But why do you say you would need 1 mV accuracy ?   Bright sunlight
 is far stronger than
 the light sources he used.
 
 
 i don't know if the measurements at sunlight would show the same
 variations.. we would have to make new measurements, but for experience,
 the variations of voltage regarding light sensing are not of
 considerable amounts, so if the accuracy is 26mv, we would have to see
 if a perceptible change in ambient light could be of a higher magnitude
 than 26mv, if not the accuracy could be lost..
 
 

i did some more experiments and at ~20 cm from the halogen lamp i doest
matter is i turn the backlight full on of off .. i dont have color
anymore
at that distance the bare led gave about 250mv (maybe a bit more into a
very high R fet gate...)

i guess it would be around 70mv whit the light guide in front of it..
(i guess this be more (150mv?) with a very high R (~25 Mohm?) fet gate
as only load)

i would add a simple amp (mosfet? or maybe cheap opamp ?)
to amplify ~X10 so 300mv would be full scale..
my memory is dusty but that should be posible with 2 resistors an a fet
? gain would be posible to change by replacing one of the resistors with
a bigger / lower value...

maybe a trasistor is better bc the leds is acts as a current source ?

ideas welcome

if i can get the partnr of a fet/transistor that would be usable (and
cheap enough) i could maybe order a couple of them from say farnell and
hack something together here

is there a free or hackable input on the current EC ? (or is that
different from the ec that will be in 1.5 ?


 (haven't checked the specs though..)
 
 
 Having the data sheet for the EC controller doesn't help --- 8 bits
 and recommended operating
 voltage for the analog reference voltage is about all it provides.  
 I had to ask a chinese speaker
 to call the app. engineer to find out the input impedance...
 
 Ok, thanks :).
  
 
 
 
 
 On Tue, May 5, 2009 at 3:24 PM, Reinder de Haan r...@mveas.com
 mailto:r...@mveas.com wrote:
 Hallo,
 
 C. Scott Ananian wrote:
 snip
 
  A last resort would be hooking up a MOSFET as a simple
 amplifier --
  again, you're not worried about linearity or any such
 niceties, but
  you'd still need a good match for your MOSFET's threshold
 voltage...
  some real measurements to replace the WAGes would go a long way.
--scott
 
 
 measured on a B1 XO1 laptop (where the leds and the series
 resistor are
 wired in parallel it seam) :
 
 almost dark: 0mv
 ~3meter away from a 8w PL; bare led: ~2mv
 ~50 cm below ~25W halogen desk lamp; bare led: ~40mv
 bright white led directly on bare led ~200mv
 bright white led directly on light guide of the bat.led (lcd
 side) ~50mv
 ~50 cm below ~25w halogen desk lamp (~75* angle to the axis of
 the light
 guide) ~5mv
 
 i measure this between  GND of the laptop the led side of the series
 resistor.
 all leds seam to be about the same.. i did not compare the different
 light guides.
 the main battery and DC power where removed, the RTC baterry was
 still
 in place.
 
 
 the meter i measured this with was fixed in the 2000mv range
 and was abou 10Mohm when i connected it to another meter in
 resistance
 mode; the (volt) meter read 250mv at that time.
 
 

[Fwd: Re: Ambient light sensing via LED response]

2009-05-06 Thread Reinder E.N. de Haan


 Original Message 
Subject: Re: Ambient light sensing via LED response
Date: Thu, 07 May 2009 00:02:49 +0200
From: Reinder de Haan r...@mveas.com
To: raf...@laptop.org
References: 200904290017.n3t0hl2v006...@new.toad.com
c5d4a4e5-b183-4b7d-bafb-3488e15f7...@laptop.org
c6d9bea0905011128j2d5cdf3cw975cfad790480...@mail.gmail.com
675d3c5c-95ed-4ee9-84bc-3b5164675...@laptop.org
c6d9bea0905042207i458ed9b1if74e0e16d24f5...@mail.gmail.com
4a00a073.8020...@mveas.com
a80d16920905051544s525b7039nf7e87a4a3c754...@mail.gmail.com
75dc0458-925b-4792-9aee-a24b9b1f3...@laptop.org
a80d16920905051952h3d82d15brb8f690cf1c402...@mail.gmail.com



Rafael Enrique Ortiz Guerrero wrote:
  
 
 
 On Tue, May 5, 2009 at 8:34 PM, John Watlington w...@laptop.org
 mailto:w...@laptop.org wrote:
 
 
 On May 5, 2009, at 6:44 PM, Rafael Enrique Ortiz Guerrero wrote:
 
 These measurements are really cool.
 
 But the question remains in whether the ADC could have a
 resolution of 1mv?, i mean in light of these measurements is
 necessary to have an ADC that can reliable sense these
 variations and then with that basis  have a transfer function
 and add it to the algorithm.
 
 
 Absolutely not.  The A/D is eight bits, with an input range spanning
 0 - 3.3V, so the best you
 can hope for is about 13 mV per LSB.  I would guess actual accuracy
 to be closer to 26 mV. 
 
 
 But why do you say you would need 1 mV accuracy ?   Bright sunlight
 is far stronger than
 the light sources he used.
 
 
 i don't know if the measurements at sunlight would show the same
 variations.. we would have to make new measurements, but for experience,
 the variations of voltage regarding light sensing are not of
 considerable amounts, so if the accuracy is 26mv, we would have to see
 if a perceptible change in ambient light could be of a higher magnitude
 than 26mv, if not the accuracy could be lost..
 
 

i did some more experiments and at ~20 cm from the halogen lamp i doest
matter is i turn the backlight full on of off .. i dont have color
anymore
at that distance the bare led gave about 250mv (maybe a bit more into a
very high R fet gate...)

i guess it would be around 70mv whit the light guide in front of it..
(i guess this be more (150mv?) with a very high R (~25 Mohm?) fet gate
as only load)

i would add a simple amp (mosfet? or maybe cheap opamp ?)
to amplify ~X10 so 300mv would be full scale..
my memory is dusty but that should be posible with 2 resistors an a fet
? gain would be posible to change by replacing one of the resistors with
a bigger / lower value...

maybe a trasistor is better bc the leds is acts as a current source ?

ideas welcome

if i can get the partnr of a fet/transistor that would be usable (and
cheap enough) i could maybe order a couple of them from say farnell and
hack something together here

is there a free or hackable input on the current EC ? (or is that
different from the ec that will be in 1.5 ?


 (haven't checked the specs though..)
 
 
 Having the data sheet for the EC controller doesn't help --- 8 bits
 and recommended operating
 voltage for the analog reference voltage is about all it provides.  
 I had to ask a chinese speaker
 to call the app. engineer to find out the input impedance...
 
 Ok, thanks :).
  
 
 
 
 
 On Tue, May 5, 2009 at 3:24 PM, Reinder de Haan r...@mveas.com
 mailto:r...@mveas.com wrote:
 Hallo,
 
 C. Scott Ananian wrote:
 snip
 
  A last resort would be hooking up a MOSFET as a simple
 amplifier --
  again, you're not worried about linearity or any such
 niceties, but
  you'd still need a good match for your MOSFET's threshold
 voltage...
  some real measurements to replace the WAGes would go a long way.
--scott
 
 
 measured on a B1 XO1 laptop (where the leds and the series
 resistor are
 wired in parallel it seam) :
 
 almost dark: 0mv
 ~3meter away from a 8w PL; bare led: ~2mv
 ~50 cm below ~25W halogen desk lamp; bare led: ~40mv
 bright white led directly on bare led ~200mv
 bright white led directly on light guide of the bat.led (lcd
 side) ~50mv
 ~50 cm below ~25w halogen desk lamp (~75* angle to the axis of
 the light
 guide) ~5mv
 
 i measure this between  GND of the laptop the led side of the series
 resistor.
 all leds seam to be about the same.. i did not compare the different
 light guides.
 the main battery and DC power where removed, the RTC baterry was
 still
 in place.
 
 
 the meter i measured this with was fixed in the 2000mv range
 and was abou 10Mohm when i connected it to another meter in
 resistance
 mode; the (volt) meter read 250mv at that time.
 
 

Re: [Server-devel] backup : problem opening /library/users/XXXX/datastore-xxxxx/store

2009-05-06 Thread Hamilton Chua
Martin,


Thanks, sorry I don't have a lot of activities to backup yet on my test
SoaS.

I'll give this a go today and report back the results here.

Best,

Hamilton



On Wed, 2009-05-06 at 19:23 +0200, Martin Langhoff wrote:
 On Tue, May 5, 2009 at 4:52 PM, Martin Langhoff
 martin.langh...@gmail.com wrote:
  Let's keep this on the list. Is that from a recent SoaS? The datastore
  storage format has changed then, and we need to add support to Moodle
  for it.
 
  More work! :-p
 
 Done - not tested much -- the zipfile you've given me didn't have much data.
 http://dev.laptop.org/git/users/martin/moodle.git/commit/?h=mdl19-xsid=5f522dbef1878284d15ae2ef0872c8dd5caa1953
 
 So I need your help in reporting whether it works well for your SoaS
 clients. I assume you're already using my moodle branch, so a mere git
 pull will get you the right code... ;-)
 
 Note: It won't list metadata-only entries. If there's no 'data'
 file, it's not listed.
 
 cheers,
 
 
 m


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