As we have seen it above, the app can save a log file in text format containing all NMEA 0183 sentences received. The app can then replay them. Log files are saved in the sailgrib/nmea directory.
When reading a log file, the application will behave as if it would receive data in real time. For example, AIS alarms will be raised.
SailGrib WR can read and play 2 formats of log files:
- SailGrib format: a text file where each line consists of a ISO8601 timestamp and a NMEA 0183 sentence.
2016-03-16T16:45:19.140Z $SDDBT,38.0,f,11.6,M,06.3,F*3E
2016-03-16T16:45:19.145Z $SDDPT,11.6,-1.0,99.0*7F
2016-03-16T16:45:19.150Z $HCHDG,331.3,00.0,E,00.0,E*40
2016-03-16T16:45:19.155Z $WIMWV,025.0,R,016.3,N,A*20
2016-03-16T16:45:19.177Z $VWVHW,129.0,T,129.0,M,07.7,N,14.3,K*52
2016-03-16T16:45:19.349Z GPRMC,164517.59,A,4601.47709,N,00114.10553,W,0008.9,303.6,160316,0.0,W,A*05
2016-03-16T16:45:19.491Z $GPGGA,164517.59,4601.47709,N,00114.10553,W,1,05,0.0,5,M,50.0,M,,*61
2016-03-16T16:45:19.594Z $GPGSA,A,3,02,03,14,23,31,,,,,,,,5.5,0.0,6.7*34
2016-03-16T16:45:20.129Z !AIVDM,1,1,,A,18vAfjo1hvwqN6PJHD8jHQrT050l,0*08
NKE format: the USB datalog Box includes a data logger that records the entire NMEA data stream and writes it on a micro SD card. You can replay the data in this file after copying it from the SD card to the sailgrib/nmea directory of your Android device.
The file will have a .nmea extension. The first line is a header, the second line indicates the starting tile of the log, the following lines are composed of a timestamp from the beginning of the recording and the NMEA sentence.
– nke Display –
- 14-07-11 10:55:54
105.230197 $IIXDR,C,9.8,C,AirTemp*17
105.264203 $IIMTW,7.0,C*24
105.529122 $IIMWD,,T,167,M,16.1,N,8.3,M*49
105.540801 $IIMWV,56,T,16.1,N,A*20
105.560855 $IIVWT,56,R,16.1,N,8.3,M,29.8,K*6C
105.577142 $IIMWD,,T,160,M,16.1,N,8.3,M*4E
105.920317 $IIDPT,7.6,,*43
105.922810 $IIDBT,24.8,f,7.6,M,,*46
105.977768 $IIXDR,C,9.8,C,AirTemp*17
106.008639 $IIMTW,7.1,C*25
106.098530 $IIMWV,45,R,19.3,N,A*29
Two log files are integrated with the app as an example:
- SailGrib type: nmealog_20160316.txt
- NKE type: 14-07-11 105554.nmea
To play a log file:
enable the Log reader mode in the NMEA Settings menu
choose the Log file to be played
return to the main screen. A banner was added at the bottom of the screen.
The left button allows you to start or pause playback.
The little slider lets you adjust the playback speed.
The great slider allows you to jump to a specific time and shows you where you are in the file.
The “reset” button on the right side allows you to return to the “live” mode.