<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On May 5, 2016, at 8:07 PM, Gary E. Miller <<a href="mailto:gem@rellim.com" class="">gem@rellim.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">Yo Frank!<br class=""><br class="">On Thu, 5 May 2016 19:49:28 -0400<br class="">Frank Nicholas <<a href="mailto:frank@nicholasfamilycentral.com" class="">frank@nicholasfamilycentral.com</a>> wrote:<br class=""><br class=""><blockquote type="cite" class="">We want to use PGGA sentence because it appears first, closest to<br class="">the start of the second in each cycle.<br class=""><br class="">You have mode set to 17, using message GPRMC. Can someone who knows<br class="">more than me, explain to me if it really matters?<br class=""></blockquote><br class="">NMEA sentences are vaiable length. So you want to use the first one<br class="">to cut jitter on the NMEA time. In practice you have the PPS, 10,000<br class="">times more accurate, so never a problem unless you lose PPS.<br class=""></div></div></blockquote><div><br class=""></div><div>And on the Adafruit HAT & Ultimate GPS breakout board, the first NMEA sentence at the start of a cycle is “<span style="font-family: Menlo; font-size: 11px;" class="">GPGGA</span>”. So are you saying that with PPS, it really doesn’t matter? Your second sentence makes me think it matters. The last sentence makes me think it **doesn’t** matter...</div><br class=""><blockquote type="cite" class=""><div class=""><div class="">Some GPS can barely get all their sentences out every second at 9600.<br class="">If you have a lot of sats in view, or optional NMEA turned on, your<br class="">buffers may overflow.<br class=""></div></div></blockquote></div><br class=""><div class="">On the above GPS, there are periodic (not every second) sentences that will cause a cycle to extend beyond one (1) second at 9600.</div><div class=""><br class=""></div><div class="">Thanks,</div><div class="">Frank</div></body></html>