diff options
author | Eric S. Raymond <esr@thyrsus.com> | 2013-11-28 20:46:22 -0500 |
---|---|---|
committer | Eric S. Raymond <esr@thyrsus.com> | 2013-11-30 10:12:49 -0500 |
commit | d20910b125a707b831171a03095cd73be3024f66 (patch) | |
tree | 7d26a28a001fd4004f7ff9847be9c954e7aff899 /www/hacking.html.in | |
parent | 81f8250dec13c7c9855626faff3c9d723388b84c (diff) | |
download | gpsd-d20910b125a707b831171a03095cd73be3024f66.tar.gz |
Documentation and FAQ updates.
Diffstat (limited to 'www/hacking.html.in')
-rw-r--r-- | www/hacking.html.in | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/www/hacking.html.in b/www/hacking.html.in index 9b95f497..0ddcf648 100644 --- a/www/hacking.html.in +++ b/www/hacking.html.in @@ -1364,7 +1364,7 @@ suppose the control string were a baud-rate change?</p> <h2 id="fifo">Setting FIFO threshold to 1 to reduce jitter in serial-message times</h2> <p>When using gpsd as a time reference, one of the things we'd like to do -is make the amount of lag in the message path from GPS to GPS small +is make the amount of lag in the message path from GPS to GPS as small and with as little jitter as possible, so we can correct for it with a constant offset.</p> @@ -1373,8 +1373,8 @@ device UART to 1 using TIOCGSERIAL/TIOCSSERIAL. This would, in effect, disable transmission buffering, increasing lag but decreasing jitter.</p> -<p>But it's almost certainly not worth the work. Rob Janssen, our timekeeping -expert, reckons that at 4800bps the UART buffering can cause at most +<p>But it's almost certainly not worth the work. Rob Janssen +reckons that at 4800bps the UART buffering can cause at most about 15msec of jitter. This is, observably, swamped by other less controllable sources of variation.</p> </ol> |