Re: Capacitor for snuffing interference to GPS antenna
Jim Colton wrote: Hey OpenMoko.com hardware team, Is the voltage on this cap. okay for me to use for the hardware solution to the GPS Problem? Capacitance is what you suggested... I want to put into place on mine if it is okay. http://www.westfloridacomponents.com/mm5/merchant.mvc?Screen=PRODProduct_Code=MON001Category_Code=MonolithicCapacitors-Chip-SurfaceMountStore_Code=wfc http://www.westfloridacomponents.com/mm5/merchant.mvc?Screen=PRODProduct_Code=MON001Category_Code=MonolithicCapacitors-Chip-SurfaceMountStore_Code=wfc I recommend NOT doing this until we understand the problem a bit better. Michael ___ support mailing list support@lists.openmoko.org https://lists.openmoko.org/mailman/listinfo/support
Re: Capacitor for snuffing interference to GPS antenna
Thomas Coppens escreveu: 2008/8/7 Michael Shiloh [EMAIL PROTECTED]: I recommend NOT doing this until we understand the problem a bit better. Michael Statements on these mailing list are often confusing because the origin isn't very clear at times. Perhaps there's a need for an official signature in messages originating from OpenMoko staff? Just a thought. Just check the person's name/email against the list at http://wiki.openmoko.org/wiki/Who_is_Who, and you will even know his/her attributions within Openmoko[1]. [1] List compiled mostly by random non-Openmoko passers-by. Might be incomplete or misleading. -- Cesar Eduardo Barros [EMAIL PROTECTED] [EMAIL PROTECTED] ___ support mailing list support@lists.openmoko.org https://lists.openmoko.org/mailman/listinfo/support
Re: Capacitor for snuffing interference to GPS antenna
Thanks Felix, All I saw from OpenMoko was to use a 10pf, surface mount. Do you know of a link from OpenMoko.org or .com that has more detail? Please refer me to it if so. I should be able to find the capacitor here in Denver, CO, USA - I've not tried very hard to find it yet. -Jim On Mon, Jul 21, 2008 at 2:47 PM, Felix Mahnke [EMAIL PROTECTED] wrote: Hi Jim, you should get one at your local parts dealer. Buying one cercap via internet is pretty expensive. Anyway, farnell sells stuff like this: http://export.farnell.com/1327626/passives/product.us0?sku=avx-04025a100dat2a regards, Felix 2008/7/21 Jim Colton [EMAIL PROTECTED]: Tommi, Did you get the recommended cap (0402) from OpenMoko? Please refer me to the source if so. Thank you, Jim On Mon, Jul 21, 2008 at 9:00 AM, Tommi Kärkkäinen [EMAIL PROTECTED] wrote: Tim Schmidt kirjoitti: On Sun, Jul 20, 2008 at 1:10 AM, Jim Colton [EMAIL PROTECTED] wrote: http://www.westfloridacomponents.com/mm5/merchant.mvc?Screen=PRODProduct_Code=MON001Category_Code=MonolithicCapacitors-Chip-SurfaceMountStore_Code=wfc Looks like that's 10uF (micro Farad), not 10pF (pico Farad) as recommended by OpenMoko. Also, it's physically too big. That's a 1206 package, the recommended cap is 0402. I'm sorry but I must say that the fact that you had to ask this suggests that you might not have the experience required to solder the capacitor. The 0402 package *is* very small. Tommi ___ support mailing list support@lists.openmoko.org https://lists.openmoko.org/mailman/listinfo/support ___ support mailing list support@lists.openmoko.org https://lists.openmoko.org/mailman/listinfo/support ___ support mailing list support@lists.openmoko.org https://lists.openmoko.org/mailman/listinfo/support ___ support mailing list support@lists.openmoko.org https://lists.openmoko.org/mailman/listinfo/support
Re: Capacitor for snuffing interference to GPS antenna
Jim Colton wrote: Greetings Felix, I see the product on that site. The capacitance is correct, but how do you know it is the correct voltage? All I have seen from OpenMoko is this: http://www.openmoko.org/wiki/Image:Gta02_gps_10pf_rework_sop.pdf .. mentioning the capacitance but not the voltage. Please mail me if you have a link to OpenMoko fully describing the part needed. Thank you, Jim Dear Jim, ceramic 10 pF capacitors are usually available with voltage specifications above 100V. Your GPS antenna only carries a couple of millivolts (unless you are standing right in the middle of a thunderstorm). Therefore the voltage specification is not critical. More importantly you should make sure that you get the correct dimensions (in mm). Thomas ___ support mailing list support@lists.openmoko.org https://lists.openmoko.org/mailman/listinfo/support
Re: Capacitor for snuffing interference to GPS antenna
I see the promising software fix being worked on here: http://git.openmoko.org/?p=kernel.git;a=commitdiff;h=1d04b142ffeaa15129f046751f1366b0f0614f47 and some test result... http://lists.openmoko.org/pipermail/community/2008-July/023062.html So I installed the latest build with the patch and got nice results with the values of these new glamo driver parameters as they came with the build. So the hardware fix is looking like a waste to do. The OpenMoko team is doing a great job and I am confident we will get their recommendation is short time. On Mon, Jul 21, 2008 at 8:35 PM, Joerg Reisenweber [EMAIL PROTECTED] wrote: Am So 20. Juli 2008 schrieb Jim Colton: Hey OpenMoko.com hardware team, Is the voltage on this cap. okay for me to use for the hardware solution to the GPS Problem? As explained din detail in other posts in this thread, voltage of this capacitor is no issue (though it's not exactly on GPS, but between VDD and clock of uSDcard). Anything with a voltage 5V will do, as long as it's 10 picoFarad size 0402 Please note that OM didn't recommend to do this rework yet. Also don't even consider to do this rework, if you don't feel comfortable with soldering SMT-components, or even didn't do this before! cheers jOERG ___ support mailing list support@lists.openmoko.org https://lists.openmoko.org/mailman/listinfo/support
