[Loadstone] Tutorial modification, Rob please.

Aedan O'Meara aomeara at iol.ie
Fri Dec 22 12:51:41 GMT 2006


Hi Rob,
Further careful exploration of Sirfdemo has resulted in me changing some
parts of the last tutorial. Please use this version instead to hellp avoid
confusion by users.
Seasons greetings
Aedan.
	Tutorial for using Sirfdemo with Holux slim 236 and Holux data cable.

by Aedan O'Meara.
Install mini disk that comes with Holux gps.
1. using data cable. Connect cable and attach Holux gps. Turn it on.
2. Open Sirfdemo and you will be put into the setup menu.
3. Select serial port option
Select the com number. This may be found in Device manager but will also be
displayed here with all other live com
 ports.
The connecting baud rate will be displayed
Untick "Use aux(auxillary) data source"
press ok
4. Under Setup choose Target s/w(software) version choose v3.0/3.1
Leave auto detect on.
press ok
5. Under Actions click on open data source.
Switch to nmea protocol will be greyed out and Switch to Sirf protocol will
be available.
Visually as you are in nmea protocol you should have data streaming only in
the Debug window. This is normal,
see note below.
Across the top of the screen using Jaws cursor you will read the Sirfdemo
title and beside that it will say
"Unknown software on com... at baud rate ...".
Now under Actions select synchronize protocol and baud rate.
Using Jaws cursor you should now have the Software version in the gps and
the baud rate of 57,600 displayed on the
top of the screen beside the Sirfdemo title.

6. Synchronizing will have put you into Sirf protocol automatically.

Data streams will change and all windows will be filled. Under actions the
highlight should move to Switch to
nmea protocol.
Switch to Sirf protocol should be greyed out.
If this doesn't happen you have not successfully gone into Sirf protocol.

Warning:
 Never play with user protocol because if you put the GPS into this without
a third party protocol in the GPS
you will loose all communication with the GPS.
Lifting one leg of the backup battery within the unit is the only way to get
back the gps in this situation.
Also never synchronize the protocol and baud rate when using bluetooth
connection as this might put the GPS
baud rate out of reach as bluetooth is fixed at 38,400.
The only way to get the gps back in this case is to lift one leg of the
backup battery within the unit, or use the Holux USB data cable.

	7. Now under Navigation go to Static Navigation.
Select disable and highlight and click send.

8. Now return gps to nmea protocol by clicking on this under Actions.
This will open a list box.
The default baud rate offered in here is 9600.
As Sirfdemo pulls the gps to its own baud you can change to nmea at 9600
successfully but you will not
then be able to use your bluetooth connection to
Loadstone as this is at 38,400.
Alter baud rate here to 38,400 to restore the gps to Bluetooth rate,
otherwise when you  connect to bluetooth gps
in Loadstone you will get the
message "gps clock has  stopped ticking, disconnecting" after about 5 secs.
( this is because the baud rate has been left at 9600 and the bluetooth baud
rate is 38,400.). You will still be
able to connect repeatedly at the bluetooth level but keep timing out.
Finally click on the Send button to finish.

Exit Sirfdemo.

Your Holux slim 236 should now be working properly with the SN turned off.

Selected Notes from Rob's tutorial list:
Answer to question about the other settings in the switch to nmea list box:
The values you put there are the message output rates in seconds between
outputs, and should be set to output the specific messages you require (or
you
mapping program needs). The default settings are 1 second for GGA, GSA and
RMC, and 5 seconds for GSV. If you want velocity and heading, you can put 1
second for VTG. GLL is available as an alternative to GGA. Set values only
for the messages you want. Note that the ??? entries are for messages a
manufacturer
may add as an extra. Most do not add any, although some SiRF receivers
support the ZDA (time and date) message in the middle of the 3 spots.
Note:

For NMEA mode, SiRFDemo only displays the messages in the Debug View window
and does not provide information in the other windows. That is normal for
the
program. The program is designed only to demonstrate receivers, so it has
some features only implemented with SiRF binary format. And since NMEA
protocol
is a universal protocol, it does not define functions to do many settings
that are unique to a specific receiver. We implemented a few features in
NMEA
(such as changing to SiRF protocol, changing message rates, etc.), but not
the others. To make those changes you must switch to binary mode, make the
changes
and then switch back to NMEA.

Carl - SiRF Customer Support

I just bought a GlobalSat BT-338. When I connect it to my PC with a BT
dongle and start the SiRFDemo 3.61 I get a lot of 'Bad parity from SV xx,
subframe
x'. For the rest the BT-338 seems to work.

Is this a software problem or is there really something wrong with the GPS?

Thanks for the answer. And if this question has already been answered, I did
not find it.
**************************************************

Reply author: gpspassion
Replied on: 07/25/2005 15:26:04
Message:

Welcome to the forums.
Sounds like you're using the wrong baudrate, make sure you select 38,400bps.

_________________________________________________________________________

Reply author: Carl at SiRF
Replied on: 07/26/2005 23:58:02
Message:

Actually, I think his baud rate was set just fine. That particular error
message means that he probably locked onto the satellites in the middle of a
word
of the navigation message. As a result he found a parity error (since he
received the correct parity bits, but not all the actual data bits). This is
a
very normal and common error when you see it at startup. Other than that,
you generally only see it when you have an actual parity error (pretty rare)
or when you have a blockage and come out of it (same reason as when you see
it at startup).

(Happens when you go into invisible cursor or Jaws cursor and when switching
back to nmea protocol, Aedan.)
Carl - SiRF Customer Support

Synchronize Protocol and Baud Rate actually only sends a command to the
receiver to go to SiRF protocol, and it does it at every baud rate and in
both SiRF
and NMEA protocol. Then it switches to SiRF protocol at 57600 where it
expects to find the receiver. If that doesn't work for you, it is probably
because
the receiver is set up to communicate at a different baud rate (e.g., 38400
for many Bluetooth receivers). If Synch doesn't work for you, after you have
tried it scan each baud rate manually, starting at 4800 and working upwards
to 115200. Assuming you find the receiver at one of them, remember that as
your receiver is likely to go there whenever it is told to change protocol.

SiRFDemo is not a passive program like many monitors -- it often sends
commands to the receiver when you aren't expecting it to. For example, if
you open
a log file, SiRFDemo sends a query for software version and navigation
settings to the receiver and logs the results in the log file so that
information
is available when the file is reviewed. Likewise, if you try to issue a
command to change some setting like static navigation, SiRFDemo queries the
receiver
to find the current setting, and if it is successful then the menu you see
will have the option already set for you (I think that one sets the option
so
that if you just click "send" it will change the current setting -- for
example, if static nav is off, it will show the default as "on" so if you
click
"send" it will change the setting).

For your current case, scan until you find where the receiver is talking,
then command it back to NMEA at the right baud rate and you should be fine.

Carl - SiRF Customer Support



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