-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Somebody in the thread at some point said:
| The software fix alone allows you to get a fast TTFF but after that, sd | card data transfers are just to noisy to maintain a high quality GPS | data stream. Yes it works but poorly, which is better than not at all. There's something to be aware of here, when getting the fix the GPS chip needs a much better Signal to Noise ratio than when maintaining it. Have a look at the first few lines of this: http://www.atmel.com/dyn/resources/prod_documents/doc4928.pdf ''... – Acquisition Sensitivity: –142 dBm (Cold Start, With External LNA) – Tracking Sensitivity: –158 dBm (With External LNA) ...'' (We have external LNA) It means it can track with a 16dBm reduction in GPS signal after it made the satellite acquisitions. So if you understood it will get a fix OK with the software workaround, and we saw many people report this, you should expect the tracking phase to work better than the acquisition phase since the signal requirement is relaxed by 16dBm. | I have two Fr's, once I get the caps(this week). I'll do the HW fix on | one, install the software fix on both, and do a side by side comparison. That'll be interesting. But in the real world many thing perturb GPS tracking and sophisticated software filters are anyway used to try to see through excursions, I guess this will be the case for typical SD Card usage pattern here. - -Andy -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iEYEARECAAYFAkiPdiwACgkQOjLpvpq7dMqNpQCdGfgx6OJlahoNMJz9p347ti4b JUAAoIhCvDCGOOlxN0eqPbYHxPkYK8nd =DEli -----END PGP SIGNATURE----- _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community