OLPC News 2007-12-22
1. Arahuay, Peru: If you haven't yet seen it, please take the time to read this AP article about the XO in remote Peruvian village (http://www.chicagotribune.com/news/nationworld/chi-laptop_webdec22,1,6878223.story). The lead paragraph says it all: Doubts about whether poor, rural children really can benefit from quirky little computers evaporate as quickly as the morning dew in this hilltop Andean village, where 50 primary school children got machines from the One Laptop Per Child project six months ago. 2. Hinge: Jacques Gagne has been investigating the laptop hinge—the clearance between the two rotating parts should be tighter and this would reduce wobble. Mary Lou Jepsen and Quanta are investigating a possible run-in change at the earliest possible date. 3. Hardware certifications and testing data: Mary Lou has created a compilation of certification and testing data that is available on the wiki (Please see http://wiki.laptop.org/go/Hardware_Testing); it will be expanded over time. 4. Green: EMPA at the Swiss National Labs is continuing its work on life cycle analysis of the XO laptops by comparing the cost, lifetime, power consumption, and overall environmental impact with the refurbished desktops in Columbia. Mary Lou teleconferenced with the team this week and will assure that they get all the data they need to complete their analysis. The final report is due in mid-February. Columbia is widely acknowledged to have one of the most successful re-furbished desktop programs in Latin America. 5. Water: Anna Bershteyn, an MIT Ph.D. candidate, has been helping OLPC follow up on some questions from Ban Samhka, Thailand about the best way to test and improve water quality; water quality is an area of interest that is expanding in the OLPC community. Anna and Mary Lou met with Susan Murcott to discuss possible simple hands-on games on the XOs that will encourage children to test and/or filter their water. SJ Klein has put Anna in touch with groups from UNICEF and the Hesperian Foundation who are also working on water safety. To learn more about Anna, please visit the wiki (http://wiki.laptop.org/go/User:Anna_B). 6. Power measurements: John Watlington instrumented a production machine for power measurements this week to allow continued verification of the laptop power-saving measures. This allows Chris Ball (and the rest of the software team) to continuously measure the power consumption at ten different places around the laptop, and also automatically simulate user input to wake up the laptop (power button, lid switch, etc.). We have already have a B3 unit with over twenty power measurement points, but it cannot aggressively suspend/resume, and doesn't have any of the more recent power-savings-related engineering changes. 7. Embedded controller: Richard Smith spent time studying oscilloscope traces looking for a possible cause of the reopening of Ticket 1835 (unable to resume); recent software builds were failing on the suspend/resume testbed. He has been unable to reproduce the problem with bare-board tests and he now feels that he fully understand the software causes of 1835 (three distinct causes). Running the latest EC code with Joyride kernels doesn't seem to have the problem. Richard and John will continue to run tests on the suspend/resume testbed to insure that we won't have the problem with Update.1 A second bonus was discovery and verification of EC issues that Chris Ball and Jim Gettys have run into. Andres helped Richard find an EC bug where the SCI mask was getting corrupted. The most frequent manifestation of that was the loss of AC events or battery-charge level. Richard still don't know the root cause of the corruption, but has a good test case and kernel debug logs. There appears to be a case where EC communication fails and error recover is not working. Fixing it is going to involve more oscilloscope time, because turning on serial- port debugging appears to make the problem go away. There is already a workaround in the kernel to fix the mask when it becomes corrupted, so it's not a show-stopper. Richard is also writing some cron scripts that will take a snapshot of the battery ACR while the laptop is running on battery power and then then send us the data. Richard wants to use these data to build power usage profiles. The ACR gives us a very accurate reading on the amount of mA/h drawn from the battery. Plotting it over time will begin to give us insight on our dynamic power draw. 8. School server We found a serious problem with the mesh networking in the build of School-server software released last week (Build 137), which brings down an active antenna if a large file transfer is attempted. A new build of the software with the new libertas driver (thanks David Woodhouse) greatly improves the situation. A new build is being tested and tuned and will be released in the next few days. The school-server-software build problems have returned, but this time we identified one of the
Re: OLPC News 2007-12-22
On 22.12.2007 17:32, Walter Bender wrote: 2. Hinge: Jacques Gagne has been investigating the laptop hinge—the clearance between the two rotating parts should be tighter and this would reduce wobble. Mary Lou Jepsen and Quanta are investigating a possible run-in change at the earliest possible date. Wasn't the clearance made wider sometime between B1 and B2 to fix the problem with interlocking plastic parts? Please explain further. 7. Embedded controller: Richard Smith spent time studying oscilloscope traces looking for a possible cause of the reopening of Ticket 1835 (unable to resume); recent software builds were failing on the suspend/resume testbed. He has been unable to reproduce the problem with bare-board tests and he now feels that he fully understand the software causes of 1835 (three distinct causes). Running the latest EC code with Joyride kernels doesn't seem to have the problem. Richard and John will continue to run tests on the suspend/resume testbed to insure that we won't have the problem with Update.1 A second bonus was discovery and verification of EC issues that Chris Ball and Jim Gettys have run into. Andres helped Richard find an EC bug where the SCI mask was getting corrupted. The most frequent Is this a hardware or software bug? manifestation of that was the loss of AC events or battery-charge level. Richard still don't know the root cause of the corruption, but has a good test case and kernel debug logs. There appears to be a case where EC communication fails and error recover is not working. Fixing it is going to involve more oscilloscope time, because turning on serial- port debugging appears to make the problem go away. There is already a workaround in the kernel to fix the mask when it becomes corrupted, so it's not a show-stopper. Richard is also writing some cron scripts that will take a snapshot of the battery ACR while the laptop is running on battery power and then then send us the data. Richard wants to use these data to build power usage profiles. The ACR gives us a very accurate reading on the amount of mA/h drawn from the battery. Plotting it over time will begin to give us insight on our dynamic power draw. This may have been asked before, but how far is the progress in freeing the EC code? IIRC first there were official statements that the EC code would be free (and all parties would agree to that), then after some time it was announced that OLPC were talking with Quanta about setting the code free, now we just hear about EC bugs, but nothing about the code. Regards, Carl-Daniel ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: OLPC News 2007-12-22
Hi Carl There is an effort to open the Ec code. http://wiki.laptop.org/go/OpenEC if you want to help you are welcome! :). On Dec 22, 2007 7:37 PM, Walter Bender [EMAIL PROTECTED] wrote: Wasn't the clearance made wider sometime between B1 and B2 to fix the problem with interlocking plastic parts? Please explain further. As I recall, we widened the base to reduce some wobble. This is an effort to further reduce wobble (in the 90 degree rotation). Is this a hardware or software bug? Software. This may have been asked before, but how far is the progress in freeing the EC code? IIRC first there were official statements that the EC code would be free (and all parties would agree to that), then after some time it was announced that OLPC were talking with Quanta about setting the code free, now we just hear about EC bugs, but nothing about the code. I don't think we'll get this code freed up because it is a tangle of ownership and licenses. But we do plan to rewrite it from scratch when we come up for air. -walter --- Walter Bender One Laptop per Child http://laptop.org ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel -- Rafael Enrique Ortiz Guerrero One Laptop Per Child [EMAIL PROTECTED] ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: OLPC News 2007-12-22
Wasn't the clearance made wider sometime between B1 and B2 to fix the problem with interlocking plastic parts? Please explain further. As I recall, we widened the base to reduce some wobble. This is an effort to further reduce wobble (in the 90 degree rotation). Is this a hardware or software bug? Software. This may have been asked before, but how far is the progress in freeing the EC code? IIRC first there were official statements that the EC code would be free (and all parties would agree to that), then after some time it was announced that OLPC were talking with Quanta about setting the code free, now we just hear about EC bugs, but nothing about the code. I don't think we'll get this code freed up because it is a tangle of ownership and licenses. But we do plan to rewrite it from scratch when we come up for air. -walter --- Walter Bender One Laptop per Child http://laptop.org ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
