The NMEA0183 Checksum Calculator is a freeware tool which is shipped with Eye4Software Hydromagic. It can be used by hardware or software developers to make sure their device or software transmits correct NMEA0183 sentences. If NMEA0183 sentences are rejected by the Hydromagic software for no reason, you can also check the validity of received or logged NMEA0183 sentences using this tool.
Generate or check NMEA0183 checksums with the freeware tool.
When a device is transmitting NMEA0183 sentences, a checksum may be added to the end of the message. If this is done, an asterisk (*) will appear first, followed by the hexadecimal representation of the XOR binary operation of all characters between the '$' and the '*'. This checksum is two characters long (hexadecimal characters in the range 0..F). Example: $TTSSS,FIELD,1,FIELD,2,FIELD,,*5C.
NMEA0183 data fragment with checksum values highlighted.
The tool can be found in the installation folder of Hydromagic. In most cases it is installed in "C:\Program Files\Eye4Software\Hydromagic\Program\" or "C:\Program Files (x86)\Eye4Software\Hydromagic\Program\" when using the 32 bit version of the software on a Windows 64 bit operating system. Start the tool by double clicking or tapping the "NMEAChecksum.exe" executable program.
The NMEA0183 Checksum Calculator can be found in the Hydromagic installation folder.
To calculate a checksum for a NMEA0183 which doesn't contain a checksum field already, you can use the first section of the application. First paste your NMEA0183 sentence in the input field and click the "Calculate" button to generate the same sentence with the checksum field included.
For example, when pasting the sentence "$GPVTG,230.0,T,231.3,M,3.0,N,5.6,K,D" into the text box, the generated sentence in the result section will be: "$GPVTG,230.0,T,231.3,M,3.0,N,5.6,K,D*24". In this case the calculated checksum is 0x24 hexadecimal.
Use the first section of the tool to calculate the checksum for a NMEA0183 sentence.
To check whether a NMEA0183 sentence including a checksum field is valid, paste the NMEA0183 sentence in the text box in the second section of the application. When clicking the "Check" button, both the reported and calculated checksum will be placed. When they match the NMEA0183 sentence is valid.
For example, when pasting the sentence "$GPVTG,230.0,T,231.3,M,3.0,N,5.6,K,D*24" in the second text box, the calculated checksums will appear in the result sectrion like this: "Sentence Checksum = [0x24], Calculated Checksum = [0x24], Result = OK". This function also checks for invalid characters which are not supported by the NMEA0183 standard.
Use the first section of the tool to calculate the checksum for a NMEA0183 sentence.
