for sending GPS Navigation Data via SMS
Version from September 3th 2006
NEW  coming soon:  TRACKBOX2

The TRACKBOX is an interface unit between a GPS Receiver and a GSM Mobile phone or Modem. Nearly all GPS Receivers provide NMEA-data output via a serial RS.232. Most  GSM mobile phones have a RS.232 data connection. The TRACKBOX reads the NMEA-data from the GPS and sends it out via the GSM phone as an SMS ( SMS = GSM Short Message-Service )  

main components of mobile installation for sending SMS

Sending an SMS can be initiated in two ways:
1. by calling the mobile GSM Unit from any phone ( one ring signal only, no cost for the caller )  

2. by pushing the SEND-Button on the TRACKBOX

An SMS with GPS navigation data will be sent out to a predefined phone number ( already stored inside the mobilephone ).
This predefined phone number can be:
a.)    the last dialed number ( LD-memory )
b.)    the first number in the internal phonebook ( ME-memory )

Entering this number is very easy ( more details are given below )
The TRACKBOX  has been tested with SIEMENS-Mobilephones ( 35, 42, 45, 55 series ), but may also run with other types of mobilephones providing full Modem-Functions ( supporting AT-commands at 19200 bps ). 

The TRACKBOX has been constructed as a Low Cost Solution where eventually already existing GPS Receivers or GPS Mouses and Mobilephones can be used again.

Why using a GSM-MODEM instead of MOBILEPHONE ?

For professional use it is recommended to replace mobilephones by special GSM-Modems. Of course this also is a matter of cost, but on the other hand, by using GSM-Modems it is possible to overcome some general problems, often existing when using mobilephones . This especially is in cases, where unattended Long-Time-Operation is required. So for example with modems it is possible, to put system into operation status simply by powering it.


1. While
mobilephone version is taking it's Target-Number from one of mobilephones phonebooks,  the GSM-Modem is using a number stored on EEPROM before. Entering can be done by connecting TRACKBOX  to PC and using a Terminal-Program ( like e.g. Hyperterminal ). 

Because some networks do not allow to switch OFF request for PIN-Code,  the modem version of  TRACKBOX after start of operation first must send required PIN-Number. Currently here only a fix code number ( 1234 ) is used, but it is planned to make this code also user selectable.


Because operation procedures between mobilephones and GSM-Modems are too different, i have given up realizing a common software for both and there will be two versions instead:
"TRKBOX-P" ( for mobilephone use ) and "TRKBOX-M" ( for modem use ).

Modem version has been tested with SIEMENS modem "TC-35T", but also other types from same company ( like M1, M20, MC-35 aso. ) or FALCOM and WAVECOM should be usable.
Operating instructions for Modem-Version can be found here   

current version of TRACKBOX board



1. What first has to be done, is storing the telephone number where SMS shall be sent to. As mentioned before, this can be:
a.) the last dialed number ( from LD-Memory ) or
b.) the first number stored in the internal phonebook ( ME-Memory ).

For "a"
 the Jumper "J2" has to be open and for "b" it has to be closed  ( to find the jumpers see photo of  TRACKBOX and also the electrical schematics )
If "a" is selected, you have to dial the phone number
( use international format starting with "+" ) and start calling this number.
Then interrupt the call after one ring and phone number is stored in the LD-Memory. That's all.
If "b" is selected, in the phones owner manual you will find a description on how to store a phone number in internal memory position no.1. Also here international format starting with "+" has to be used.

With Jumper "J3" CLOSED, SMS will be sent in "Flash-Mode". This means, that the SMS are shown directly on  the display of receiving phone, but will NOT be stored on it's SIM-Card. This mode is not allowed, when using program SMS2OZI. So "J3" should normally be left OPEN.

3. Jumper "J4" is used for selection between sending NMEA-Protocols Type "RMC" ( OPEN  )  or "GGA" ( CLOSED ). Standard setting is OPEN, but sending "GGA" could be interesting in case e.g. altitude values are required.


4. When powering the TRACKBOX-Board, it already must be connected to mobilephone or modem. After the stored number has been red from selected phonebook, the CALL-LED will flash for a few seconds. Now the system is ready for operation.  

5. After required target number once has been loaded from phonebook and stored on board, jumper "J1" can be closed permanently. This will disable the function for automatic load and refresh. In case TRACKBOX always is using the same target number, it is recommended to use this function, because this will improve system reliability.   

6. Upon receiving a call ( no connection; no cost ) incoming RING-Pulses will be detected. After detection the CALL-LED will flash for a few seconds. Now program is searching for actual GPS-Data ( RMC- or GGA-Protocols ) coming  from GPS-Receiver. After processing, it will be sent as an SMS to target number previously stored on board and CALL-LED will light continously for a few seconds.

7. ALARM-SEND: By connecting "SEND" ( "alarm send contact" Pin 7 ) to ground for a short moment ( about 1 second ), the program is looking for actual GPS-Data and sending  it immediately.

Von hier sind die Texte deutschsprachiger Konfigurations- und Bedienungsanleitungen herunterladbar:

ELECTRICAL SCHEMATIC OF TRACKBOX  ( may be changed without notice ) 

electrical schematics

J1 *
Disable automatic reading from Phonebook
J2 *
Table 1
function of  jumpers/switches J1-J4

*) In case modem software is used, function of switches "J1" and "J2" is different from mobilephone version. After "J1" is "CLOSED / ON", board will start operation in configuration mode. When connected to PC, target number can be entered by using a terminal program ( like Windows HyperTerminal ).
If not required, sending the fix Pin-Number "1234" can be omitted by setting "J2" to "CLOSED / ON".
"J3" and "J4" functions are same as shown in table 1.         


The TRACKBOX sends RMC- or GGA-Type raw NMEA-Protocols as SMS. Next picture shows how it could appear on display of receiving GSM-Unit ( depending on type of mobilephone ).

After a little bit of experience, Navigation-Data can be interpreted quite easily. "$GPRMC" is protocol-header; data was sent at UTC: 07:34:08 ( hhmmss ); "A" marks data to be VALID ( "V" would mean: INVALID ); "5000,182,N" is latitude ( ddmm,mmm ) NORTH and "00806,881,E" is longitude ( dddmm,mmm ) EAST; "063,4" is speed ( knots )  and "264,5" is heading ( degrees ); "301098" is date sent ( Oct. 30th, 1998 ); "000,7,W" is magnetic declination. Protocol is completed by sending  checksum "6D".
For more information on NMEA-Protocols click here.

RMC-Protocol like shown on display of receiving GSM-Unit

( REM: used mobilephone did not decode first character "$" correctly )


Navigation-Data, like those sent from TRACKBOX, can be decoded much more comfortable by using the program  SMS2OZI:

( click on picture for full-size view )

Short-Messages containing NMEA-Data can be evaluated by using SMS2OZI in conjunction with well known map software OziExplorer.
Besides this, SMS2OZI also can be used to call Online-Maps:

sample for calling online maps
( click on picture for full-size view )
in addition to NOKIA mobilephones, SMS2OZI now also is supporting mobilephones and GSM modems fom SIEMENS.

NEW for PDA users:

From author of SMS2OZI there also is a new software named OZI2OZI. It mainly has been made for transfering GPS navigation data between different Pocket-PC's. This is done by using the short message service  ( SMS ) available with all GSM nets. In case map software OziExplorerCE has been installed on same PDA, incoming position data also can be visualized on maps. Besides file format used for transfering data directly from PDA to PDA, OZI2OZI also is decoding NMEA protocols type "RMC", like e.g. sent from TRACKBOX.

(C) LVermGeo RLP

( click on pictue for full-size view )


Fig. 8  
layout of  TRACKBOX-Board ( size: 100x50mm )

* for position of parts also see Fig.2

* jumpers ( red  ) need to be installed on component-side

* jumper connecting "U3" Pin2-Pin8 must be installed before inserting socket for "U3"

For secure operation it is recommended to provide additional cooling for 5V-Regulator "U5".
   This can be done by using a suitable heat-sink

* 5V-Out from regulator can be used for powering e.g a GPS-Mouse ( required current is about 200mA )


 data-In ( GPS ) : 
 NMEA ( RMC or GGA protocols )
 datarate ( GPS ) :
 4800 bps
 level ( GPS ) :      
 RS.232 compatible 
 data-In/Out ( GSM ) :
 control by ETSI compatible AT-Commands
 datarate ( GSM ) :
 19200 bps
 level ( GSM ) :
 RS.232 compatible ( for use with standard data cables )
 software versions :  
 "TRKBOX-P" tested with SIEMENS mobilephones series  35, 42,
 45, 55, 60 and S25
 "TRKBOX-M" tested with Siemens modem "TC-35T"  
 ( SIEMENS models  "M1", "M20" and "MC-35" and modems from  FALCOM or  WAVEVOM also should be usable )   
 ( tested Nokia mobilephones phones did not work )
 supply :       DC ~9-15V /~50mA  ( current without powering external GPS-Rec. )
 PCB dimensions :  
 100x50mm ( board without Sub-D-Connectors )  

Table 2


Available are :
* special
parts ( like programmed processors, EEPROM-Chips, crystals and pcb's )
* assembled and tested boards 
Sorry, but complete kits or housed boards are not yet available.

If interested send me an E-Mail:

A smaller TRACKBOX PCB ( Fig.9 ) has been made for usages, where interfacing via RS.232 is not required. Schematics ( Fig.10 ) is shown a sample, where board directly has been connected to one of newer types of SIEMENS mobilephones ( starting with series 55 )  and also can be powered from it. Software is same as with "normal" TRACKBOX.

PCB Tiny-Trackbox


Schematics Tiny-Trackbox

12 pin plug SlimLumberg ( Fig.11 ) is used for connecting PCB to SIEMENS mobilephone.  Board will be powered via pin "A" ( ca. +4V ) and "D" ( Ground ).

Slim-Lumberg connector

Pin "B" and "C" are used for serial data interfacing ( TTL level, data rate: 19K2 ).
In case RS.232 level NMEA signals are available from GPS receiver ( or mouse ), pins "F" and "D'' ( Ground ) are used ( data rate must be 4K8 ). Via input "E" ( and without transistor TR1 being assembled ), also TTL levels signals will be accepted.  By grounding pin "G" an immediate SMS sending ( alarm function ) can be initiated.

Fig.7:  "Geobasisdaten (TK25)  (C)  Landesamt für Vermessungswesen und Geobasisinformation Rheinland Pfalz  31.8.2006 ; Az.: 26 722-1.401".