GPS data logging software for the
Pocket PC
From
Xylon Data Capture for
the Pocket PC
Contents:
LicenceAgreement
Overview
Xylon Data Capture is a
Pocket PC application for capturing large amounts of GPS data quickly and
efficiently with a high degree of flexibility. We originally wrote this
application after looking for a data logger suitable for capturing large
volumes of data cost effectively without the burden of using a laptop PC.
Xylon captures and stores
GPS information as required and configured by you. This is true low cost
flexible data acquisition, the only requirements being a Pocket PC and GPS
capture module. Depending upon your requirements you can use anything from a
$60 GPS board to a real time kinetic system. The only requirement is that the
GPS transmits in the NMEA 0183 ASC format which most do.
A major feature of Xylon is
the dual capture mode which allows you to capture a continuous stream of data
which will plot your course, you can simultaneously capture extra readings to a
separate file with codes of your choice attatched. For example, if you wish to
drive along every road in a town and log every pothole requiring repair you can
define a code as “pothole” and as you drive past each hole just press the
record button and a separate string with the code “pothole” attatched is saved
to file. All the while you are doing this another file is constantly capturing
data to record your entire journey. This data can be processed and plotted
straight on to a local map and given to a contractor who is to carry out the
work. You can further refine this task by adding as many additional codes as
you like to define, for instance, the depth of pothole or the repair priority
level.
You could use this same
method of logging for recording anything from your progress in a round of golf,
the position of speed cameras, the beat of a security officer, giving precise
time and location information plus the recording of certain codes in key
locations to ensure an inspection has taken place. For more detailed
information on how Xylon works download the manual or download a trial version.
The trial version is limited to 200 journey points and 50 coded logging points.
Once you have downloaded the
Xylon.zip file extract the contents to a separate folder, ensure that your
pocket pc is connected to the desktop. Run setup and the installation process
will begin. Setup should interrogate your Pocket PC and install the correct
files for your processor, if this does not happen do the following procedure.
On the Pocket PC from the
start menu select Settings, System, About. You will see information about the
processor, for instance on the Ipaq it is ARM SA1110.
Unzip the contents of the
zip file which corresponds to your processor type into the same directory as
setup and run setup, the installation should now proceed.
Any problems email us
Getting Started:
Once you have downloaded the
programme choose which processor type you have in your Pocket PC and extract
and install the appropriate module onto the Pocket PC.
Go to the Settings menu on
the PPC and select Connections, PC. Make sure the checkbox beside the message
“Automatically synchronize when serial cable is connected, using:” is cleared
otherwise the GPS unit will be unable to connect with Xylon, if you leave the
box checked and connect the GPS unit you will see a message flash up on the
screen saying “Attempting to connect to host” and Xylon will not work.
Set the appropriate comms
parameters for your gps unit (if
enabled), the normal default comm. values are
Baud: 4800
Parity: None
Data bits: 8
Stop bits: 1
The Pocket PC is set to
these values by Xylon.
Ensure that the GPS Unit is powered up. And select Xylon either from the Start Menu or via Start, Programmes, Xylon.
Start Up:
When Xylon is started the first screen you see is as shown below left, when data capture commences the screen will change to that shown on the right. The screen may look rather complex but it is designed to let you see as much information as possible. The constantly changing values displayed show that data capture is taking place satisfactorily.
Startup Screen Screen
during data capture
Xylon automatically starts
to capture data in tracking mode, your position is being recorded right from the
start. The default files that are used for initial data capture are
TrackData.csv and RefData.csv for tracking and reference points respectively.
These files are stored in My Documents.
Screen Display:
- Records Captured: This cell contains the number
of records captured to date in this session.
- Time GMT: The time in 24hr clock format
displayed as Greenwich Mean Time. Time displayed is the time when the last
record was captured.
- Sats in View: Displays the current number of
satellites in view.
- $GPGGA: etc: is the current string being
captured to fix position, see NMEA 0183 ASC codes for more detail.
- Blank cell displays secondary string being
captured (see 1.3)
- Capture Interval: The frequency with which you
wish to take readings, you can set this from the Settings Button.
- Your Position: The three cells beneath display
raw data NMEA readings for Northing Easting and Height.
- Settings: Use this button to display the
Settings screen, adjust capture intervals, captured strings, capture
files.
- Set Code: Use this button to define various
codes for your supplementary readings.
- Tracking On: Toggle this button to turn the
constant tracking feature on and off, useful if you are stopping to take
supplementary readings and don’t want to clutter the drawing with
superfluous information. Button toggles to red for clarity when tracking
is turned off.
- Use Code Off: Default value, toggle this button
to assign your pre-defined codes to supplementary readings.
- Save Position: Press this button each time you
wish to save a supplementary reading. The currently set code will be added
to each reading until you either change or cancel it.
When you press the Settings button from the startup screen the display will change to that shown below.
Screen Display:
- Select NMEA string to capture: Use the dropdown
box to select the primary NMEA string to capture to the Tracking File.
- Secondary NMEA capture: Use the dropdown box to
select the secondary NMEA string to capture to the Tracking File.
- Capture Interval: Use the drop down box to
select the capture interval (1 to 60 seconds).
- Tracking File Name: The default name for the
tracking file is displayed or you can select a filename using the browse
button.
- Supplement File Name: This is the file where
extra readings and codes are saved. The default files will simply append
data to the existing file unless you chose to either overwrite them or use
a different file name.
- File Name for Capture of All Data:If you wish to capture all data strings either use the default file name (SaveAll.csv) or select a different file name using the Browse button.
- OK: Press the OK button to exit this process and return to data logging.
When you press the Set Code button from the startup screen the display will change to that shown below.
Screen
Display:
Code
1-5: Tap any of the buttons and the code currently displayed in the drop down
box will be assigned to that code number.
Pothole: Either select a code from the drop down box or type a new one in to this box, assign the code as described above. The current code assignments are listed in the lower part of the screen. Press OK to accept the definitions.
When you press the
Use Code: Off button from the startup
screen the display will change to that shown below.
Code1-5: Press Code
1 – 5 buttons to display the code assigned to that number. The current code
(pothole) will be assigned to all further supplementary points logged until the
code is changed.
Apply: Press this button to exit the process and return to data logging.
The illustration below shows the main screen with secondary capture enabled, note the message which flashes up every time you save a supplementary coded point which confirms that the point has been saved and shows the code applied.
There is an option
to save all data, which will save every single string received (sample file),
this can cause problems due to overload on the PPC. We recommend saving 2
strings at 2 second intervals as an optimum configuration. The amount of data
you can capture this way is limited only by the storage available on your PPC.
The default communication parameters
for NMEA output are 4800 baud, 8 data bits, stop bit, and no parity.
Table
4-1 NMEA-0183 Output Messages
Global Positioning System Fix Data (GGA)
$GPGGA,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,M,<11>,<12>,<13><CR><LF>
1)
UTC time of position fix,
hhmmss.sss format
2)
Latitude, ddmm.mmmm format.
3)
Latitude hemisphere, N or S.
4)
Longitude, dddmm.mmmm format.
5)
Longitude hemisphere, E or W.
6)
Position Fix Indicator,
0 = fix not available, or invalid.
1 = GPS SPS Mode, fix valid.
2 = Differential GPS, SPS Mode, fix valid.
3 = GPS PPS Mode, fix valid.
7)
Number of sate1lites in use,
00 to 12.
8)
Horizontal Dilution of
Precision, 0.5 to 99.9.
9)
MSL Altitude, -9999.9 to
99999.9 meters.
10) Geoidal height, -999.9 to 9999.9 meters.
11) Differential GPS (RTCM SC-104) data age, number of seconds
since last valid RTCM transmission (nu1l if non-DGPS).
12) Differential Reference Station ID, 0000 to 1023. (null if
non-DGPS)
13) Checksum.
Geographic Position with
Latitude/Longitude
$GPGLL,<1>,<2>,<3>,<4>,<5>,<6>,<7><CR><LF>
1)
Latitude, ddmm.mmmm format.
2)
Latitude hemisphere, N or S.
3)
Longitude, dddmT1.mmmm
format.
4)
Longitude hemisphere, E or W.
5)
UTC time of position fix,
hhmmss format.
6)
Status, A = data valid or V =
data not valid.
7)
Checksum.
GNSS DOP and Active Satellites (GSA)
$GPGSA,<1>,<2>,<3>,<3>,,,,,<3>,<3>,<3>,<4>,<5>,<6>,<7><CR><LF>
1)
Mode 1, M = manual, A =
automatic.
2)
Mode 2, Fix type, 1 =not
available, 2 = 2D, 3 = 3D.
3)
PRN number, 01 to 32, of
satellite used in solution, up to 12 transmitted.
4)
PDOP-Position dilu1ion of
precision, 0.5 to 99.9.
5)
HDOP-Horizontal dilution of
precision, 0.5 to 99.9.
6)
VDOP-Vertical di1ution of
precision, 0.5 to 99.9.
7)
Checksum.
GNSS Satellites in View (GSV)
$GPGSV,<1>,<2>,<3>,<4>,<5>,<6>,<7>,…<4>,<5>,<6>,<7>,<8><CR><LF>
1)
Total number of GSV sentences
to be transmitted, 0~3.
2)
Number of message, 0~3.
3)
Total number of satellites in
view, 00 to 12.
4)
Satellite PRN number, 01 to
32.
5)
Satellite elevation, 00 to 90
degrees.
6)
Satellite azimuth, 000 to 359
degrees, true.
7)
Signal to noise ratio (C/No)
00 to 99 dB, null when not tracking.
NOTE:
Items <4>,<5>,<6> and <7> repeat for each satellite in
view to a maximum of four (4) satellites per sentence. Additiona1 satellites in view information
must be sent in subsequent sentences. These fields will be null if unused.
8)
Checksum.
Recommended Minimum Specific GNSS Data
(RMC)
$GPRMC,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11><CR><LF>
1)
UTC time of position fix,
hhmmss.sss format.
2)
Status, A = data valid, V =
data not valid.
3)
Latitude, ddmm.mmmm format.
4)
Latitude hemisphere, N or S.
5)
Longitude, dddmmm.mmmm
format.
6)
Longitude hemisphere, E or W.
7)
Speed over ground, 0.0 to
1851.8 knots.
8)
Course over ground, 000.0 to
359.9 degrees, true.
9)
Date, ddmmyy format.
10) Magnetic variation, 000.0 to 180.O.
11) Degrees
12) Checksum.
Course Over Ground and Ground Speed
$GPVTG,<1>,T,<2>,M,<3>,N,<4>,K,<5><CR><LF>
1)
True course over ground, 000
to 359 degrees.
2)
Magnetic course over ground,
000 to 359 degrees.
3)
Speed over ground, 00.0 to
999.9 knots.
4)
Speed over ground, 00.0 to
1851.8 ko/hr.
5)
Checksum.
File Format
The
default extension for files used for
saving GPS strings are .csv, the standard extension for Microsoft Excel comma
delimited files. You can change this if you wish. The files can be edited in
any text editor or spreadsheet programme.
Sample GPS cature String
$GPGGA,145121.999,5121.2199,N,00032.5133,E,1,06,2.1,175.9,M,,,,0000*0A