[time-nuts] Monitor for Thunderbolt and other GPS receivers

Didier Juges didier at cox.net
Fri Jul 11 16:47:52 EDT 2008

Well, I don't really have much time right now, but I started working on a
Monitor for the Trimble ThunderBolt (and other GPS receivers). With 3 TBs
here, it would make sense.
Here is where I am at the moment:
The idea is to decode the TSIP packets 0x8F-AB (Primary Timing Packet) and
0x8F-AC (Supplemental Timing Packet) which the Thunderbolt sends by default
once per second.
These packets are defined in the Thunderbolt manual.
They provide most of the information of interest to simply monitor the
status of the TB.
If anyone is interested (or already has a TSIP parser in C) feel free to let
me know.
I am open to suggestions about what would make the most sense to display. I
would like the default screen to have date/time at the top, and disciplining
status at the bottom. Other data could be displayed optionaly by pressing a
I may also write a NMEA parser for the other GPS receivers I have here.
This project uses a Silabs processor, which is part of the 8051 family.
Please don't ask me why I am not using a PIC, Atmel, ARM, (put your favorite
micro here), processor instead, there is nothing wrong with any of these
chips and they all would work. 8051 is what I have tools and code for, and
they are cheap enough for me.
If there is enough interest, it would not be very hard or expensive to make
a small PWB for the processor (the DIP version would be easier to solder),
the voltage regulators, the pot (to adjust screen contrast), a push button
(to select among a couple or more of screen content) and the RS-232
Didier KO4BB

More information about the time-nuts mailing list