OpenPlotter Depth, STW, Temp

[belizesailor]

As my venerable Raymarine instruments become more difficult & expensive to repair/replace, Im considering moving to OpenPlotter. Ive tracked down most of the sensors I need, but not finding much on depth/temp and STW (speed thru water).

What are some of the options currently in use for these sensors?

[Dsanduril]

Have you looked at CruzPro? They sell several transducers that output NMEA 0183. Haven't tried them yet, but have had them on the radar because of similar questions.

Airmar also has things like the DT800 that is NMEA 0183 output.

Getting those into OpenPlotter is generally trivial.

For more options, but a little more complexity you could look at NMEA 2000 transducers. Tons of those, you just need the CANBUS adapter for your platform to get the data into OpenPlotter.

Again, haven't actually done any of it, have just been tracking various options as the time is coming when I'll be doing the same thing.

[conachair]

Originally Posted by belizesailor

As my venerable Raymarine instruments become more difficult & expensive to repair/replace, Im considering moving to OpenPlotter. Ive tracked down most of the sensors I need, but not finding much on depth/temp and STW (speed thru water).

What are some of the options currently in use for these sensors?

Waiting for this to come out for STW >

https://www.nasamarine.com/product/electromagnetic-log/

Depth one of the few too important not to have standalone so ST60 does that (& STW at the moment). Water temperature you could maybe just stick a ds18b20 thermometer to the hull.

[Bill O]

As mentioned by Dsanduril, look at the Airmar smart sensors. Lot to choose from for the NMEA output of your choice.
We have a full array Tacktick (now Raymarine) for wind, depth, stw and temp and work well w/plotter. If you search in the xreference for Ticktack they sell a DST800 that covers all your needs in 1 thru hull. If you look around the Airmar site you can find other sensors that would also work.


Bill O.

[Dsanduril]

FWIW If you're thinking long term I'd probably go NMEA 2000. Sure the connectors and cable are expensive, but on the plus side you get power and signal in one go, ease of adding additional instruments/sensors, and a plethora of options at the other end for display. Searching around at industrial automation places for M12 DeviceNet connectors/cables/hubs may save a bit on materials costs and doesn't lose you anything.

Note that if you have Ray SeaTalkng and will have a 'mixed' install their older implementation was physically non-compliant with NMEA 2000 standards (adapters available), but they have been chastised and are making changes to become physically compliant.

[mikedefieslife]

Any NMEA 2000 or if you like to go retro NMEA 0183 sensor should work. These will be active sensors in that they process the signal internally. Getting them to work in Openplotter/OpenCPN is simple. However both will need some form of adapter either the Can-USB for the NEMA2000 one, or RS422 USB for the NMEA0183 sensor.

Avoid all inactive passive sensors. These relay on the external display to do the processing, and won't work for your needs.

It's particularly tricky, because popular triducers like the Airmar DST800 are available in NMEA 2000, 0183, and passive.

[Dsanduril]

To me the tricky part is the wiring. If you switch to active sensors then you need to get them power. Your existing transducers probably don't require much in the way of power, and what they need they get from their display head over the sensor cable. Active sensors will require both signal and power connections, and the existing transducer cables are unlikely to be suitable - which unfortunately may mean tearing apart half the boat in order to pull in a new cable for an active sensor. That, too me, is the hard part (and breaking out the wallet of course, but it's a boat project so that's a given).

[belizesailor]

Both speed and depth transducers are in the port hull as is the nav station where the R'Pi will most likely live so thats not much of a cable run to goto active NMEA 2000.

The anemometer is of course at the mast head...a bit more involved cable run. Or...a little Arduino project to convert the existing analog data to NMEA/Signal K. [emoji6]

[belizesailor]

Thanks all. Lots of options to consider now.

[Moo]

Originally Posted by mikedefieslife

It's particularly tricky, because popular triducers like the Airmar DST800 are available in NMEA 2000, 0183, and passive.

Avoid the DTS800 series triducers as the temperature sensor always fails. Over time the reading slowly creeps higher until eventually failing. I see this mode of failure all of the time on client's boats.



Just stick a sensor to the hull either networked to your instruments or just using a standard home/garden temperature display.

[conachair]

Originally Posted by belizesailor

The anemometer is of course at the mast head...a bit more involved cable run. Or...a little Arduino project to convert the existing analog data to NMEA/Signal K. [emoji6]

Or an esp8266/esp32 and send the data over wifi. The Pi pins are quite fragile & having thermometers barometer /voltage sensors etc going to a different place can be handy. Mine just has wired gps/ais usb data connections, everything else goes in as signalk over wifi from an esp8266.

[mikedefieslife]

Originally Posted by Moo

Avoid the DTS800 series triducers as the temperature sensor always fails. Over time the reading slowly creeps higher until eventually failing. I see this mode of failure all of the time on client's boats.



Just stick a sensor to the hull either networked to your instruments or just using a standard home/garden temperature display.

Will keep an eye on that. Thanks. Mine is at least 5 years old. Still going strong so far.

[belizesailor]

Originally Posted by conachair

Or an esp8266/esp32 and send the data over wifi. The Pi pins are quite fragile & having thermometers barometer /voltage sensors etc going to a different place can be handy. Mine just has wired gps/ais usb data connections, everything else goes in as signalk over wifi from an esp8266.

Im already set up for Arduino development, but learning the ESP8266 could be fun.

Looks like the Arduino IDE (a rather generous moniker, given its relatively primitive functionality) supports ESP or you can use Lua Script tools (oh boy, yet another proprietary language). What do you use for development?

[conachair]

Originally Posted by belizesailor

Im already set up for Arduino development, but learning the ESP8266 could be fun.

Looks like the Arduino IDE (a rather generous moniker, given its relatively primitive functionality) supports ESP or you can use Lua Script tools (oh boy, yet another proprietary language). What do you use for development?

I use the arduino IDE, programming an ESP8266 or 32 just the same as programming an arduino with some different libraries but mostly you won't really notice which device is plugged in. There's also an over the air library which lets you upload new sketches over wifi which makes life so much easier when the little board is hidden away somewhere and you want to change something. Some stuff on git already to make life easier though I cut and paste my own code mostly. Having run openplotter on a Pi for a while now the real gold dust IMHO is having plots of battery voltage and current in/out. Voltage is just a ads1115 across the terminals and an INA219 piggy backed across a battery monitor shunt gives surprisingly accurate current after some calibration. Various engine thermometers are great as well and accurate plotted barometer readings get looked at a lot, maybe not essential but really interesting
Plotting is easy, just install influxdb database and chronograf to look at it, sigK has an app to write whatever data you want to the database, no ned to create tables etc, influxdb does all that for you.


https://github.com/mxtommy/SigkSens

[belizesailor]

Oh boy, more geeky stuff! I used to be an IT guy, its fun getting back into it a bit.