Analog to Digital

[BigAH]

New to owning a boat, I just got a 1990 Sylvan Super Sport and already looking at upgrades. I’ve got 2 gauges that need to be replaced but is there something out there that has a Chart Plotter and Depth Finder that can also display the information from my gauges? Like a All-in-One that I can mold into my dash in place of the gauges.

 

[alldodge]

Being a 1990 I don't think the motor would be compatible unless its been replaced with a newer model. But if there is @dingbat might know

 

[dingbat]

New to owning a boat, I just got a 1990 Sylvan Super Sport and already looking at upgrades. I’ve got 2 gauges that need to be replaced but is there something out there that has a Chart Plotter and Depth Finder that can also display the information from my gauges?

Most units on the market today have a gauge display of some sort as part of the NMEA 2000 interface.

Your motor doesn’t support a digital interface. You would need to convert the existing analog signals from the sensors or gauges to digital (NMEA 2000). You would also need to install a NMEA 2000 back bone to get the now digital data to the chart plotter.

 

[BigAH]

Most units on the market today have a gauge display of some sort as part of the NMEA 2000 interface.

Your motor doesn’t support a digital interface. You would need to convert the existing analog signals from the sensors or gauges to digital (NMEA 2000). You would also need to install a NMEA 2000 back bone to get the now digital data to the chart plotter

Most units on the market today have a gauge display of some sort as part of the NMEA 2000 interface.

Your motor doesn’t support a digital interface. You would need to convert the existing analog signals from the sensors or gauges to digital (NMEA 2000). You would also need to install a NMEA 2000 back bone to get the now digital data to the chart plotter.

Ok, thanks. So I would need an Analog Gateway to convert to Digital then I would be able to connect any NMEA 2000 interface?

 

[dingbat]

Basically…..the limitation is going to be the converter. What analog signals does it support?

If you want to simply replace the gauges the Garmin GMI 20 is a neat little display once you get your NMEA 2000 network setup

Garmin GMI™ 20 Marine Instrument | Sailing

The GMI™ 20 Marine Instrument designed to displays depth, speed, wind and 100+ marine and vessel parameters for power and sail vessels.

www.garmin.com

 

[sam am I]

Setup and test using Garmin Echomap DV with MarineNow NMEA 2000 signal converter

It works!!! The Chinese have cracked and busted the bottom out of the money monopoly knows as NMEA 2000 for $115....lol, love it!!!

The needles on each gauge lights/show up (seen here as red needles, cept tach as it had no sig) when data for that gauge is present, I used resistors to simulate voltages present on various inputs. Note types of sensors (and its resistance range) the unit expects to see at its inputs.

The unit requires at least 9V (12V'ish here) on its "Volt Input" for two things
1) Turns on network ID so the Garmin can config it, seen here as two entries of "MARSplus"(see below)
2) Current loops for the sensors (see below)

The manu uses 5mA current loops on the sensors inputs, e.g., for fuel gauge 0-190 ohm

5mA * 0 ohms = 0V
5mA * 190 ohms = 0.95V

Hence the voltage ranges on that input from 0V to 0.95V for a full tank to a empty tank when used with the standard 0-190ohm fuel sender. And so on and so forth for the other sensors as well.

The Garmin will see and auto config the port sensors (when present) to its engine 1(see below)

Oh and config the dip switches for your tach, I've set mine for 12 poles.("ratio 6")

 

[Eric 3.7LX Alpha 1]

So guys, with this NMEA 2000 signal converter, you keep the existing sensors in the engine? Oil pressure, water temp... etc.. very slick indeed. I just picked up a Raymarine Axiom 9 to replace my 25 year old grey scale Garmin plotter & fishfinder, I'm going to go this route also. Does the converter get installed at the helm or engine?

 

[dingbat]

So guys, with this NMEA 2000 signal converter, you keep the existing sensors in the engine?

Yes

Oil pressure, water temp... etc.. very slick indeed. I just picked up a Raymarine Axiom 9 to replace my 25 year old grey scale Garmin plotter & fishfinder, I'm going to go this route also. Does the converter get installed at the helm or engine?

Unless you want to run wires back to the individual sensors at the motor, install at helm and wire into the gauges.

 

[sam am I]

So guys, with this NMEA 2000 signal converter, you keep the existing sensors in the engine? Oil pressure, water temp... etc..

Yes BUT.............

1) Make sure your "passive" sensors are the correct resistance/s (see spec sheet I included) that the converter is expecting to see as this proper resistance range creates the proper voltage range (See my math example above and also the units "Level Sensor Signal" switch )

2) Or if the sensor is a voltage output type (e.g., an "active" sensor if you will, that has a supply voltage to it, wired typically as +12V/+5V, Gnd, and Vout, see wiring image below), has an output voltage in the range of the voltage that the passive sensor was creating with it's 5mA current loop (See my math example above, this could be mod'ed with a voltage divider to scale properly if need be)

Does the converter get installed at the helm or engine?

Doesn't matter, but probably centrally near the majority of the sensors seems logical, so motor'ish as personally I'd try to keep sensor/analog wiring as short as possible and make the longer run the digital CAN bus.........NMEA cable to your Chart Plotter.