Steve Holton wrote: > Do you have a way to accurately measure relative humidity? > > I saw pretty severe trackpad issues on one of my XO's on a single day > and haven't seen a re-occurrence yet. > At the time, it looked clearly related to static fields. > > On the other hand, I have seen (and fixed) a very similar behavior on > a NintendoDS touchpad which was caused by dust or sand becoming > trapped under the frame along one edge. > > > Just a theory (I have no data to indicate this works) but when you see > the touchpad problem on an XO could you try this and report back with > success/failure/experiences: > > On an XO showing jumpy trackpad problems: > > 1. Raise the screen to full vertical / perpendicular. > 2. Rotate the screen 1/8 turn clockwise (reverse this for left-handers) > 3. With the right hand palm facing up, reach under the screen and > put a finger on the metal mounting bracket or screw of the > swivel hinge. > 4. With the finger still in contact with that (essentially a > chassis ground), lightly brush the trackpad with a finger of the > other hand to drain stray static charges into the chassis. > 5. Re-calibrate afterwards, if necessary. > > > If you have an available earth ground, discharging to that as well > might make an interesting variation on the test. > >
Most that touchpad issues arise from two distinct sources: driver and capacitance grounding. In touchpads, the finger acts as a virtual grounding device. Dust/dirt/grime may create problems with this grounding effect. So, cleaning the pad and grounding any extra static buildup (Steve's solution above) should help. I don't know much about touchpad driver issue(s) if any with the XO. See http://en.wikipedia.org/wiki/Touchpad#Theory_of_operation http://www.synaptics.com/technology/cps.cfm http://www.synaptics.com/products/touchpad_faq.cfm#Q2 Sameer > > > > > On Sun, Apr 27, 2008 at 7:50 AM, Bryan Berry <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>> wrote: > > Day 3 of the pilots at Bishwamitra and Bashuki and couple of > issues have > come up > > 1. We are having a lot of trouble w/ jumpy cursors. You know where the > touchpad behaves erratically. Is there an easy fix to this problem? > > we are using build 703, MP machines, and firmware Q2d14. We have the > kids hold down the 4 corner buttons as recommended in the XO user > guide > but that doesn't seem to consistently fix the problem. > > Dust is an issue at the schools but that can't explain the high > rate of > jumpy cursors. Please assist > > Suggestions? > > 2. For future reference: In general the kids and teachers find it > quite > confusing when they move the cursor to the corners of the screen > and the > Sugar frame pops up. The kids have learned the top row keys very > quickly > - faster than I thought - and they find the frame popping up quite > confusing. They have learned to use the frame button already. > > pictures to come and a full write-up, I promise! > > Bryan W. Berry > Systems Engineer > OLE Nepal, http://www.olenepal.org > > > > _______________________________________________ > Olpc-open mailing list > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > http://lists.laptop.org/listinfo/olpc-open > > > > > -- > Steve Holton > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > ------------------------------------------------------------------------ > > _______________________________________________ > Olpc-open mailing list > [EMAIL PROTECTED] > http://lists.laptop.org/listinfo/olpc-open > _______________________________________________ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel