Example NMEA-0183 Sentences

Here's a log of the Raspberry Pi Multiplexer's output I wrote about previously.

$GPGGA,171059.000,3749.9201,N,12228.4985,W,2,09,1.0,-6.1,M,-25.3,M,5.0,0000*6E
$GPGSA,M,3,17,19,28,13,15,24,30,06,48,,,,1.9,1.0,1.6*3D
$GPRMC,171059.000,A,3749.9201,N,12228.4985,W,3.1,168,310716,,*03
$GPVTG,167.62,T,,M,3.1,N,,K,D*10
$GPZDA,171059.000,31,07,2016,,*5D
$IIHDM,163,M*38
$IIHDT,177,T*3D
$IIXDR,A,4,D,ROLL,A,-2,D,PTCH,A*1A
$TIROT,-0.0,A*16
$PFEC,GPatt,177,-2,4*7C
$IIMDA,29.95,I,1.01,B,19.8,C,17.0,C,68.0,,16.7,C,,,,,,,,*3F
$IIXDR,P,1.01408,B,Barometer*2B
$IIXDR,C,19.8,C,AirTemp*26
$IIMMB,29.95,I,1.01408,B*42
$IIMTA,19.8,C*05
$SDDPT,0.9,0.50*6B
$SDDBT,3.2,f,0.9,M,0.5,F*0B
$VWVHW,177,T,,M,4.2,N,,K*4D
$IIVDR,20,T,,M,1.3,N*39
$VWVLW,0.0,N,0.0,N*4C
$YXMTW,17.0,C*14

This is a great resource to get each sentence's definition, although you will find the MDA sentence here.

The "PFEC" sentence is a proprietary sentence used so that my Furuno RD30 display can read roll and pitch. I use the free NKE Marine Electronics app on my phone to display everything, so I include a few XDR sentences so that it recognizes them (same with GPVTG).

Out of curiousity, I'm going to compare the costs here between a DIY setup and a professional one (minus all the blood and sweat of course).

DIY Setup

Compass/Accelerometer	$12
Atmospheric Sensor	$15
USB GPS	$30
DST800	$250
Raspberry Pi	$40
Assorted Cables	$100
Total	$447

Professional Setup

Airmar 220WX*	$1154
DST800	$250
Regatta Processor**	$8,324
NMEA WiFi	$461
Total	$10,189

* the Airmar 220WX has a compass, accelerometer, GPS, and weather station all in one unit. However, I personally don't think having a GPS at the top of a rocking mast will produce very good GPS data

** the Regatta Processor calculates the VDR sentence, or Tidal Set and Drift (speed and direction of the ocean current)

By doing the work yourself, it'll cost you about 4% of what a professional installation would cost (granted, if you're doing professional work, you should definitely get a professional setup).

Well that's pretty cool. Next up is to make an NMEA wind instrument like this or this ultrasonic wind sensor.