[Community-news] OLPC News 2007-06-02

[Walter Bender]

1. NYC: OLPC, Quanta, Fuse, Gecko, and Pentagram met at the Pentagram
office to do the final mechanical design review for B4. B4 build is
scheduled for June 22. At least 2000 units will be built over a
one-to-two week period; we are trying to find a way to build more
units if possible.

2. Washington DC: Nicholas Negroponte and Walter Bender spent Thursday
at the World Bank. Our host was Ruth Kagia, Education Director. A
presentation to ~50 staffers and a hour-long Q&A session both
dispelled much misinformation about OLPC and generated enthusiasm for
the OLPC mission.

3. Power adaptors: Mary Lou Jepsen's investigation of burn
temperatures for children's skin resulted in UL lowering their maximum
temperature allowed for the OLPC AC adaptor from 85C to 75C. (When was
the last time that a company seeking certification helped make the
specifications tougher?)

4. Certification: 10 B3 laptops have been sent to UL for certification
testing. They will be tested for UL60950. Uruguay has asked for our
water-resistance certification. Mary Lou is investigating testing: we
will likely be able to achieve IP42 and perhaps better. IP42 means
that a test wire 1mm in diameter shall not penetrate the housing and
water that is dripped at a rainfall rate for 2.5 minutes in each of 4
different positions shall also not penetrate the housing. We may be
able achieve something better, such as IP54, which tests if a
suspension of talcum powder ends up in the housing (unlikely due to
our fanless operation) and water is sprayed for 10 minutes from a
series of nozzles (might be possible in the closed tote-mode of the
laptop).

5. Server: Fuse presented a new concept design for the server that
allows fans outside the housing of the server to cool it down
continuously in a chimney type.

6. Batteries: MIT Materials Science Professor Sadoway visited OLPC
this week to discuss battery chemistry Mary Lou, Richard Smith, and
John Watlington. As a result of his visit we are investigating our own
tests of charging LiFeP at higher ambient temperature, as well as
sampling, lifetime recycling.

7. Mesh: Marcelo Tosatti, who celebrated his birthday this week,
working with Dan Williams, Javier Cardona (Cozybit), and Ronak
Chokshi's team at Marvell, reached a milestone: working autonomous
mesh operation while the XO is suspended. Richard Smith worked with
Marcelo, CozyBit and Mitch Bradley to verify that the WLAN wake up is
working. (Signals from the WLAN are causing the EC to generate system
call interrupts, but the kernel is yet not waking up correctly.)

Mesh testing also continues. In certain cases, having an environment
without other radio sources is necessary in order to strongly
correlate cause and effect. Michail Bletsas joined H.T. Kung's group
at Harvard Univesity's Soldier's Field for testing a setup where the
school gateway enforces fair internet access among a group of
dispersed laptops.

8. Network: Dan also continued to chase the libertas patches and has
been driving the changes upstream into the kernel.  He has also been
spending time on NetworkManager upstream, trying to get the next
release into shape for use in OLPC. There are a lot of features in the
next planned release (0.7) that he's already back-ported into our
build that will be picked up when we upgrade. Dan and the Collabora
team continue work on the Presence Service; it is nearly feature
completed with a stable API.

9. Sugar: Ben Saller worked on text indexing in the data store, which
should make it easy to search in the Journal. Tomeu Vizoso and Marco
Gritti have both been working on the browser and on the cleaning up
the data store and Sugar interactions. They have also been refactoring
code in preparation of putting it into new build images. John Palmieri
spent time on the totem video player browser plugin. He also spent
some time looking into what it will take to move to Fedora 7. (Fedora
7 was released on May 31st.) Chris Ball hooked up our ebook flip
sensor to rotate the screen automatically, which involved patches to
the kernel, the hardware abstraction layer (HAL), and Sugar. Chris
also established a Sugar tinderbox (See
http://dev.laptop.org/sugar-tinder/). Upcoming features include
runtime testing of activities and RSS and e-mail notification of
new/failed builds. Muriel de Souza Godoi will be working Eben Eliason
on refining the UI in many of our standard Sugar activities.

10. X Window System: The Geode LX has a significantly more capable
graphics engine than the GX, which makes investing in optimizing its
driver more important. Further, it is time to complete work on the
input issues relating to screen rotation; this requires working on the
"master" branch of X.org. Bernie Innocenti and Jordan Crouse worked on
updating the Geode driver to the current X.org master branch, and
fought and fixed a number of rendering bugs. There are some more bugs
to be chased and squashed exposed by testing, though it again
functions
adequately for Sugar's current use. Jim Gettys refreshed his knowledge
of xkb in preparation to adding keysyms now that the keyboard is
finalized and our UI needs more clearly understood.

11. Power management: Adam Jackson worked on display-controller (DCON)
power management.  The Geode has "compression buffers" that can
greatly reduce bandwidth use for graphics by compressing pixels on
their way to the screen. But even better is to be able to turn off the
video output entirely, which the DCON makes possible, in which the
Geode will entirely power down that part of the screen. A discovery by
Mitch that enables us to restart the video unit on the Geode with
almost no latency means that we can use DCON mode much more
aggressively than we had expected, and may find it unnecessary to deal
with compression buffers. We also want to dynamically control the
frame rate; we can save 60mw (significant in ebook mode) by driving
the panel at 25hz rather than 50hz. Adam has started on this work.

12. Kernel: Andres Salomon synced the kernel up with 2.6.22-rc1.
Unfortunately, this seemed rather broken; this week, Andres synced
with 2.6.22-rc3, and it behaved much better. Andres also pulled in a
new libertas driver. Marcelo discovered a bug in our suspend/resume
code that was triggered by the updated kernel code; with that fixed,
suspend/resume works in master again. (There is still some remaining
console corruption that needs to be worked out.) Andres started
digging into the vserver capabilities, which is key to the deployment
of BitFrost.

13. Firmware: Mitch worked on stabilizing the firmware for B4: he
fixed minor bugs 1580, 1577, 498 and serious bug 1609. He reverted the
automatic "freeze screen" (quiet boot) behavior due to the OS support
not being ready for it. You can still use it by adding a "freeze" line
in olpc.fth, and changed the startup sound so that you have to press a
game key to hear it.

Note: Q2C14 is not recommended for general use; a new release will be
issued as soon as Mitch get official EC bits from Quanta.

14. Embedded controller: Mitch added support for a new embedded
controller (EC) command protocol to Open Firmware (OFW). Richard Smith
worked on implementing the protocol. The protocol is mostly complete
and partially tested. Its currently working well enough to switch the
kernel over to using these commands. The next firmware release will
have this new protocol enabled. Richard also tested an EC code drop
from Quanta which worked on resolving some of our blocker bugs.

15. Hardware: John Watlington spent most of the week rewriting and
updating the XO Hardware Design Specification. This is the document
that describes the basic hardware features of the XO in detail. The
electrical design of the B4 is completed. There are very few changes
from the B3 design, just fixes for remaining small problems. The
motherboard was released by Quanta for circuit board fabrication.

16. From the community: Rob Savoye reports that since ffmpeg isn't
(and probably will never be) included in the OLPC builds, he built a
binary tarball of Gnash with full audio and video support. (The Gnash
build for 406 has no video support enable for Flash codecs.) You can
download this snapshot of the upcoming Gnash release from
ttp://gnashdev.org/olpc/download.html. The tarball gets installed in
/usr/local, and the plugin gets installed in /usr/lib/mozilla/plugins.
The embedded video performance is adequate, streaming performance is
around 3-5 fps max. (This was on a B1. B3 results will be reported
soon.)

-walter

-- 
Walter Bender
One Laptop per Child
http://laptop.org