USB S e a Ta l k < - > N M E A Converter Installation and Operation Manual Hardware Version : V 3.5 with galvanic isolation Software Version : V 1.62 July 2010 © 2004-2010 All Rights Reserved © 2004-2010 Alle Rechte vorbehalten http://www.gadgetPool.de FWallenwein@gadgetPool.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Contents Table of Contents Credits / Warning / Disclaimer...............................................................................................3 Function overview..................................................................................................................4 Installation..............................................................................................................................
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Credits / Warning / Disclaimer The protocol converter is a RESEARCH PROJECT. It is used for research on data communication, computer communication and data conversion on computers used on board boats. Hard- and Software are still under development and have NOT been fully tested. Malfunctions of the protocol converter and of any connected device are possible at any time. Never use this product as your only source of navigation data.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Function overview The converter interconnects two different data communication systems – SeaTalk1 and NMEA. ● Information from the SeaTalk bus is transformed into NMEA Data and sent to the USB port of the boat computer. • Information from navigation software in NMEA format is transformed into SeaTalk data and sent to the SeaTalk bus. Installation The USB-SeaTalk NMEA bridge comes with two connectors.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Driver installation. Depending on your operation system it might be necessary to install a driver software. The bridge uses a standard FTDI USB Serial Converter. Linux : A normal LINUX system does not need any driver installation. It will recognise the USB chip and connect it to port /dev/ttyUSB0. If you already have another USB-Serial converter connected to your system, the bridge will be connected to /dev/ttyUSB1 or /dev/ ttyUSB2 etc. .
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Initial startup Once the drivers are installed, it's time for a first test and to adjust the device to your needs. ● For our first tests and configuration, we don’t want to be distracted by incoming SeaTalk Data. Therefore - Unplug the SeaTalk port. ● Connect the device to the USB port of your computer. ● Find out which port has been assigned by the operating system. ( See above ) ● Open a terminal program.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter You will see an empty terminal screen. In the status bar, Hyperterm will show “Connected”. Type : $SWVERSION in capital letters and press ENTER. While you type $SWVERSION, you will not see what you type. The bridge does not echo what you type. After you pressed the ENTER key, the bridge will display it’s software version string. If the bridge does not respond, press ENTER and try again.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter SeaTalk and NMEA Data NMEA Input The SeaTalk NMEA Bridge reads and writes NMEA Data to/from the USB Port. Processing of incoming NMEA data starts, when a complete NMEA sentence has been received ( $xxxxx,.....) from the boat computer If the received sentence contains a checksum, this checksum is used to check for communication errors. If the checksum does not match the sentence, the received NMEA sentence is discarded.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter NMEA Output The converter continuously checks for new incoming SeaTalk data. Incoming SeaTalk data is converted to NMEA Data and transferred to the NMEA-USB Port. The following NMEA sentences can be sent : $IIDBT $IIVHW $IIMTW $IIVLW $IIMWV $IIHDM $IIRMC $IIRSA $STALK $SNBSE Depth below transducer Optional $IIDPT can be sent instead of $IIDBT Speed t.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter SeaTalk Input When a SeaTalk datagram was received the system checks if this datagram is known and should be processed. When the datagram is known, all datagram parameters are extracted and stored. Any unknown datagram is ignored. (Exception: $STALK is sent even for unknown datagrams ) At this time the following SeaTalk datagram’s can be received.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter SeaTalk Output The converter periodically checks if any new data has arrived from NMEA, that needs to be sent to SeaTalk. New data is written to the SeaTalk bus only if the bus is not in use by any other instrument. If the bus is in use, the converter waits for a while, and tries again. Collision detection With SeaTalk it can happen, that two instruments try to send data at the same time. This may causes a data collision on the SeaTalk bus.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Same type of Data on NMEA & SeaTalk Information available from like instruments on both Busses ( SeaTalk & NMEA ) are not converted. Example: We have a depth sounder on the SeaTalk Bus and another depth sounder on the NMEA bus. So, on both sides depth information is available. In this case no depth information in transferred from one bus to the other. If depth information is not updated within 30 sec.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter The $STALK sentence The converter can process a special NMEA-like sentence. With this special sentence any SeaTalk command can be sent to SeaTalk. $STALK,cc,p1,p2..,pn*xx cc = SeaTalk Command p1 = Parameter1 p2 = Parameter 2 .. *xx = NMEA checksum ( optional ) . This special sentence will also be sent to the NMEA Bus (USB) for every received SeaTalk datagram – regardless as to whether it was recognised and processed or not.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Configuration settings The SeaTalk NMEA converter can be configured to meet the users requirements. The configuration is made by sending a NMEA-like sentence. The settings are stored in an EEProm. The configuration sentence is: $SNBSE,address,data ( SNBSE = Seatalk NMEA Bridge Set Eeprom ) Most configuration settings a read only, when the bridge gets switched on.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Example 2 : In this example, we configure the bridge, so that it only translates data from SeaTalk to NMEA – but does not send anything to the SeaTalk Bus. , , In your terminal program type $SNBSE 16 0 The bridge will respond $SNBSE,16,0.000 Next time you switch the bridge on, it will not send anything to the SeaTalk Bus but it will only listen for SeaTalk data and translate them to NMEA. © 2004-2010 All Rights Reserved HW Version 3.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Addresses and descriptions for $SNBSE Sentence Address 0 1 Data 1 = Send out every incoming SeaTalk datagram as "$STALK....." to NMEA 0 = Do not generate $STALK,xx,yy sentence for each incoming SeaTalk datagram If you don’t really need this function – better switch if OFF. It causes additional load on the NMEA Bus.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter 12 13 14 15 Not used with USB SeaTalk NMEA Link Not used with USB SeaTalk NMEA Link 0 = Speed over Ground from NMEA input is sent to SeaTalk bus as Speed over Ground and as Speed through Water ( Needed for ST60 Wind instrument, that does not recognise Speed Over Ground ) 1 = Normal operation. No special SOG => STW handling) (default) ( See Webpage www.gadgetPool.de for more on this special ST60 Wind function.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Reading actual configuration settings: In your terminal program, enter $SNBSE,address ( Example : $SNBSE,0 The bridge will respond ) „ $SNBSE,0,0.001„ - Parameter 0 is currently set to 1 - ( Example : $SNBSE,1 The bridge will respond ) „ $SNBSE,0,0.005„ - Parameter 1 is currently set to 5 - © 2004-2010 All Rights Reserved HW Version 3.5 GI/ SW Version 1.62 Page 18 of 23 http://www.gadgetPool.de FWallenwein@tklinux.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter Software update The Software can be updated by using the built in Bootstrap-Loader function. If you find anything missing in the Software, if you should find any software errors or if you have new ideas – just sent a mail to FWallenwein@gadgetPool.de I can send new / revised software by E-Mail and you can update the controller software yourself. Bootstrap method advantages : No Hardware programmer needed. Just a PC Software is needed.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter PCB Layout © 2004-2010 All Rights Reserved HW Version 3.5 GI/ SW Version 1.62 Page 20 of 23 http://www.gadgetPool.de FWallenwein@tklinux.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter SeaTalk & NMEA conversion Table Function Depth SeaTalk ID 0 NMEA DBT Stalk -> NMEA NMEA->Stalk X X X X Speed t. water 20 VHW Speed t.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter News and Info on the web. If you have any question or suggestions – there is a SeaTalk NMEA Bridge forum on our web page. http://www.gadgetPool.de Errata © 2004-2010 All Rights Reserved HW Version 3.5 GI/ SW Version 1.62 Page 22 of 23 http://www.gadgetPool.de FWallenwein@tklinux.
S e a Ta l k < - > N M E A S e a Ta l k < - > R S 2 3 2 Converter ASCII Table Upper case letters Character A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Lower case letters a b c ……………….. x y z Digits 0 1 2 3 4 5 ASCII Value 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 97 98 99 120 121 122 48 49 50 51 52 53 © 2004-2010 All Rights Reserved 6 7 8 9 54 55 56 57 HW Version 3.5 GI/ SW Version 1.62 Page 23 of 23 http://www.gadgetPool.de FWallenwein@tklinux.
