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authorEric S. Raymond <esr@thyrsus.com>2005-02-14 02:52:12 +0000
committerEric S. Raymond <esr@thyrsus.com>2005-02-14 02:52:12 +0000
commit51c14f1b1b101d27ad6a9c8442cb6d3a6f1a4319 (patch)
treecdb3935e1d509af4c920afd15430b28e6b18ed41 /HACKING
parent0b6fad5d2ee5112b101e2fc28679d0844d252e5a (diff)
downloadgpsd-51c14f1b1b101d27ad6a9c8442cb6d3a6f1a4319.tar.gz
Don't use colons in B command.
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@@ -28,6 +28,13 @@ subsecond precision; I recommend using ntpd, which will normally give
you about 15 microseconds precision (two orders of magnitude better than
GPSes normally report).
+Another helpful command is B. Without arguments, it triggers a response
+of the form <baudrate> <bits> N <stopbits>, e.g. "4800 8 N 1" describing
+the communications parameters of the link to the GPS. If profiling is
+enabled, B may be followed by an equals sign and a baud rate; the link
+will then change to that rate. This feature is not enabled by default
+because it is not secured and can be used to effectively disable the GPS.
+
The distribution lincludes a Python script, gpsprof, that uses the
Z command to collect profiling information from a running GPS instance.
You can use this to measure the latency at each stage -- GPS to daemon,