Re: Serious side effect of #6299 (silencing salut so gabble can connect)
On Thu, 2008-02-14 at 17:56 -0200, Ricardo Carrano wrote: If you don't turn many XOs on at the same time, you won't have salut preventing gabble to work. My fear is that we are complicating things unnecessarily. But we _do_ turn on many XOs at the same time. Hell, we've seen one teacher putting the kids through what seemed like rifle drill, opening them up by numbers at the start of the lesson... -- dwmw2 ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Serious side effect of #6299 (silencing salut so gabble can connect)
On Thu, 2008-02-14 at 17:56 -0200, Ricardo Carrano wrote: If you don't turn many XOs on at the same time, you won't have salut preventing gabble to work. My fear is that we are complicating things unnecessarily. But we _do_ turn on many XOs at the same time. Hell, we've seen one teacher putting the kids through what seemed like rifle drill, opening them up by numbers at the start of the lesson... Thanks David, that's useful information. Two premises (that need confirmation) 1 - It seems that running neither of two (salut and gabble) brings us some serious troubles (for now, at least). 2 - The fall back mechanism (if gabble then shut salut down) seems an easy fix. So, my suggestion is that we just test the scenario where only 2 is activated. It should be an easy test to make. I agree that there is a chance of it not working, but It is worth testing anyway, because: 1 - It is an inexpensive test 2 - there is a chance (maybe small, I agree) it might save us a lot of work. It is a shame we don't know the timings involved. I even think to myself (and also write it down ;-) if gabble can handle the rifle drill, anyway. A good thing we will have an opportunity to test this soon. -- dwmw2 ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: using the browser as an activity platform : pyxpcom / hulahop / Gears
On Feb 16, 2008 6:21 PM, Samuel Klein [EMAIL PROTECTED] wrote: The core use here is being able to use the browser as activity platform -- letting web developers good at JS code and test on most any platform, and develop something that can be a first-class activity within Sugar. One example is Dan's javascript spreadsheet, anothe ris a dynamic library (see for instance http://wiki.laptop.org/go/Dynamic_library), another is an existing web service online that one might want to run locally. In addition to pyxpcom, let me add Google Gears as a useful piece of this platform, especially when offering local use of popular online tools. Off the top of my head, MediaWiki, MindMeister, I copy Ben Lisbakken, a gears maintainer, who reports that there is a Gears patch to make it work without extension support... Is there any way that one could get involved with the google-gears-on-the-xo spec drafting/implementation process? This is something I might be interested in contributing to, but I cannot find anything about it on the wiki. -FFM ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Semi-successful Bayer-mode capture from internal camera
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 I have created a stepwise procedure for experimenting with Bayer mode capture: 1. su - 2. yum install python-imaging 3. wget http://dev.laptop.org/~bemasc/bayertest.tar.gz 4. tar xzvf bayertest.tar.gz 5. cd bayertest 6. python bayertest.py bayertest.py will produce a file output.png containing your picture, after interpolation by dcraw. Sample Raw bayer: http://dev.laptop.org/~bemasc/storefront_input.png Sample Interpolated: http://dev.laptop.org/~bemasc/storefront_output.png HUGE BUG: 1. After each reboot YOU MUST OPEN Record (or any other program that uses gstreamer to access the camera) BEFORE RUNNING bayertest.py. Otherwise, your images will be squished into the left half of the field. I have no idea why. It's pretty weird. Other bugs: 2. The included, patched version of dcraw assumes a bayer-grid orientation that does not match the camera's. Therefore, the temporary files are rotated by 180 degrees, and then rotated back afterwards. This is only an annoyance if you want to look at the raw data yourself. 3. The rightmost 4 pixels of each line are just repeats. I have no idea why. -BEGIN PGP SIGNATURE- Version: GnuPG v2.0.7 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHuJl2UJT6e6HFtqQRAkvoAJ4qm4++SAic3QUZD+FQdK+rPmQ9aQCeLqQB znVoSQZpGuP/OPt2UnJMHZc= =yNK/ -END PGP SIGNATURE- ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Semi-successful Bayer-mode capture from internal camera
From this resource: http://www.quickcamteam.net/documentation/how-to/how-to-enable-raw-streaming-on-logitech-webcams If Bayer images are captured in any resolution lower than the maximum resolution supported by the sensor, clipping occurs. For example, if the sensor supports 1280x960 and a 960x720 image is recorded, the frame will appear clipped at the right and lower borders. ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: bar code scanners on the XO
On Feb 15, 2008, at 4:35 PM, Benjamin M. Schwartz wrote: As you are probably aware, it is possible to read barcodes from the camera, using software analysis. We have code in git that encodes arbitrary (but size-constrained) data as a redundant datamatrix barcode and shows it on the screen, and code that performs image analysis from a camera capture when one XO is pointed at another with such a barcode on the screen to decode the original data: http://dev.laptop.org/git?p=projects/barcode;a=tree The original purpose was to facilitate a physical public key exchange (digital introduction) by holding two laptops up to one another. -- Ivan Krstić [EMAIL PROTECTED] | http://radian.org ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: bar code scanners on the XO
On Feb 15, 2008, at 4:24 PM, Walter Bender wrote: Has anyone used a USB bar code scanner on the XO? I've used several, both CCD- and laser-based. They register as normal keyboards, so no extra support is required; there's a CCD-based one in my office if you want to play with it. For reference, Uruguay is using these: http://www.nationalbarcode.com/datalogic/DataLogic-Firescan- D131.htm -- Ivan Krstić [EMAIL PROTECTED] | http://radian.org ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: bar code scanners on the XO
On Feb 17, 2008, at 4:39 PM, Ivan Krstić wrote: For reference, Uruguay is using these: Once more, with the link unmangled: http://www.nationalbarcode.com/datalogic/DataLogic-Firescan-D131.htm -- Ivan Krstić [EMAIL PROTECTED] | http://radian.org ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Digital Introduction (was: bar code scanners on the XO)
On Feb 17, 2008 9:36 PM, Ivan Krstić [EMAIL PROTECTED] wrote: On Feb 15, 2008, at 4:35 PM, Benjamin M. Schwartz wrote: As you are probably aware, it is possible to read barcodes from the camera, using software analysis. We have code in git that encodes arbitrary (but size-constrained) data as a redundant datamatrix barcode and shows it on the screen, and code that performs image analysis from a camera capture when one XO is pointed at another with such a barcode on the screen to decode the original data: http://dev.laptop.org/git?p=projects/barcode;a=tree The original purpose was to facilitate a physical public key exchange (digital introduction) by holding two laptops up to one another. So what happened to the idea? I'd think it would be interesting. Any reason it was scrapped? -FFM ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Signal power level (eth0 and msh0)
* Why is the signal level indicated by iwconfig in eth0 and msh0 different ? There is one module which is tuned to one frequency, so I can't understand why it should be different ? * What does the noise power level indicate in physical terms ? The module is tuned to one particular frequency, how does this relate to noise power and/or how it this being calculated ? thanks Arjun ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Signal power level (eth0 and msh0)
On Sun, Feb 17, 2008 at 08:14:20PM -0500, Arjun Sarwal wrote: * Why is the signal level indicated by iwconfig in eth0 and msh0 different ? There is one module which is tuned to one frequency, so I can't understand why it should be different ? I don't know. But the signal level for managed mode is the path from the access point to the receiver, and for mesh mode will vary instant by instant according to which mesh node is transmitting. Perhaps the data is averaged. The snr for each mesh neighbour can also be found with iwpriv. I suspect that the Linux network interface simplication simply does not hold true for this novel design. * What does the noise power level indicate in physical terms ? The module is tuned to one particular frequency, how does this relate to noise power and/or how it this being calculated ? I don't know. But in my tests noise level represents the expectation of interference from other radio sources, therefore it goes up with solar flux, temperature and proximity to population clusters. There has to be sufficient difference between the noise level and the signal level before the signal can be used. -- James Cameronmailto:[EMAIL PROTECTED] http://quozl.netrek.org/ ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Digital Introduction (was: bar code scanners on the XO)
On Feb 17, 2008, at 7:47 PM, ffm wrote: Any reason it was scrapped? It wasn't scrapped; it's on the backburner because higher-priority issues needed to be dealt with first, and the subsystems that would most benefit from an out-of-band public key exchange (like Telepathy) can't deal with KCM-style PKI yet. -- Ivan Krstić [EMAIL PROTECTED] | http://radian.org ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Serious side effect of #6299 (silencing salut so gabble can connect)
Ricardo Carrano wrote: Two premises (that need confirmation) 1 - It seems that running neither of two (salut and gabble) brings us some serious troubles (for now, at least). In case you missed some of the mails, it turned out only Pippy needed fixing in the short term, and that's now done as of Joyride-1701. We should therefore be OK. We need someone at 1cc to test whether that build does indeed notice the schoolserver and keep salut off for 2 minutes while it tries to connect to the jabber server. You would need some laptops on salut on the appropriate mesh channel so you can see their absence running this build, and you would need a schoolserver running the jabber server. Also, try it with the jabber server disabled so you can verify the salut buddies come back after 2 minutes (the time we disable salut). 2 - The fall back mechanism (if gabble then shut salut down) seems an easy fix. So, my suggestion is that we just test the scenario where only 2 is activated. It should be an easy test to make. Let me clarify how Presence Service runs the Telepathy Connection Managers (CMs): * Initially we had only gabble while salut was being developed. * When we added salut, it was in such a way that the CMs could run independently and simultaneously. * However, with both CMs running there's nothing in the UI that shows which connection a given buddy is on, or a given activity. So not all the buddies in mesh view can be invited to a given shared activity, or see a given shared activity. * In the runup to Trial 2 (IIRC) we turned the simultaneous running of CMs off, so that it would be clear that all buddies you can see at a given time should be able to participate in a shared activity. You therefore see either server buddies (gabble) or mesh buddies (salut). The current algorithm, as it has been since then, is to start both plugins (server_plugin talking to gabble, and linklocal_plugin to salut) when Presence Service starts, and then whenever gabble succeeds in connecting to the jabber server, stop salut (linklocal_plugin) and whenever gabble disconnects from the server or otherwise goes away, restart salut (linklocal_plugin). This means that in practice, if you have a working jabber server configured, Presence Service starts both, and salut succeeds in connecting first. You then see mesh buddies for a short time, while gabble is connecting to the jabber server. Here's the key: *if* gabble succeeds in connecting to the jabber server, *then* we stop salut. That is a problem in an overly busy mesh, because we are not able to connect to the jabber server. That's the meltdown scenario we are trying to avoid, by detecting the evidence of a schoolserver on the mesh, and stopping salut for a short while to give gabble a chance to connect. This would only work if all the laptops did the same - so if a bunch of laptops were fired up at the same time, they would all simultaneously *not* run salut, succeed in connecting to the jabber server, and then run using unicast, which should not overwhelm the mesh. Morgan ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
