[ntp:questions] got the Sure GPS on order, how do I program it

Terje Mathisen "terje.mathisen at tmsw.no" at ntp.org
Wed Mar 7 08:29:20 UTC 2012

Ron Frazier (NTP) wrote:
> On 3/6/2012 6:15 AM, Terje Mathisen wrote:
>> Ron Frazier (NTP) wrote:
>>> Hi all,
>>> OK, I went and ordered the Sure GPS board, cables, box, hardware, etc. I
>>> even bought a cheapie soldering station for $ 20. Other than the
>>> mechanical setup which I can figure out and the patches which David
>>> Taylor has documented, I need to know how to program the unit when it
>>> comes.
>>> Specifically, can someone tell me how to:
>>> * change the baud rate
>>> * change which sentences are output
>>> * change the update interval
>>> * enable waas, if that matters for timing
>>> * set fixed location mode, if available
>>> * restore nav mode
>>> * do a warm restart
>>> * do a cold restart
>>> * do a reset to factory defaults
>>> * save the settings to flash or backup memory so I don't lose them when
>>> it's powered off
>>> * if possible, output only the GPZDA sentence
>>> * Any other magic you think I should know.
>> I wrote a program to do exactly what you want, I think I posted a link
>> to the source code and (windows) executable.
>> If you can't find it, email me.
>> Terje
> Hi Terje,
> (Anyone can answer.)
> I found this old message from April by you. Here's part of it.
> quote on ->
> I.e. the proper programming setup seems to be:
> 1: Listen to incoming chars.
> 2: After a CRLF sequence, start a timer: If a new char arrives within
> less than 40 ms, goto 1.
> 3: Send '0', start timer waiting for CD to drop.
> 4: If CD drops before any new chars arrive, we are ready to send our
> command, so send it out before the 100 ms gps timeout.
> <- quote off
> So, here's my question. Based on your comments, the Sure board is using,
> and driving the CD line for it's own purposes. So, if we're soldering a
> wire to the CD line on the RS-232 connector, aren't we going to be in
> conflict with the boards own functions?

No, my DCD observations seems to have been spurious, the gps will 
respond to commands even if I ignore the protocol above.


- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"

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