[time-nuts] GPS receiver time message offsets to 1PPS (updated)

Mark Sims holrum at hotmail.com
Thu Jul 28 13:06:59 EDT 2016

Lady Heather keeps the date/time time in two sets of variables. One is the receiver time message values in UTC (or GPS) time.  The other is local time (UTC/GPS adjusted for time zone or time scale) that is used for the clock displays.  There are integer year,month,day, hours,minutes,seconds values and a double precision fractional seconds value.   All time calculations are done using these variables converted to Julian date/times.

The Motorola format time message has the hours,minutes,seconds fields and a separate nanosecond correction field (which can be positive or negative), which I convert to double by dividing by 1.0E9.  Turns out I had moved some code around and accidentally wound up dividing it by 1.0E9 again a few lines down, effectively wiping out the nanosecond correction.

The Z38xx time string has no fractional seconds value and I was not setting it to 0.0 when I decoded the #T2 format time string.  Originally I only supported the #T2 format, but when I added support for the #T1 format,  I moved the line that cleared the fractional seconds value to the #T1 code instead of copying the line.

Ahhh, the subtle joys of copy-paste code editing...


> And the problem was?

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