Wanted: Analogue depth sounder to nmea converter.

[gtflash]

Wanted nmea depth sounder or a converter to convert my old analogue to nmea

[Pikey Dave]

Look at Actisense. Are you converting NMEA0183 to NMEA2000? That's pretty straightforward. If your analogue sounder is outputting a different format e.g. Seatalk, it could be more problematic

[gtflash]

It’s a lowrance blue style depth sounder, but my plotter has no input for a sounder. I either need to buy a new plotter, a converter so it’s displayed via nmea and on my evinrude gauges or a stand alone depth

[Pikey Dave]

Originally Posted by gtflash

It’s a lowrance blue style depth sounder, but my plotter has no input for a sounder. I either need to buy a new plotter, a converter so it’s displayed via nmea and on my evinrude gauges or a stand alone depth

I'm not 100% sure, but are you saying that you have a transducer, but nothing to plug it into? If so, you need more than an analogue/NMEA converter. You actually need a sonar unit. The transducer simply converts electricity to sound. The head unit does all the jiggery pokery to convert the transducer signals into anything meaningful. Can you post a photo of what you've got?

[gtflash]

Hi PD. It’s possible I have completely under thunk this.

I have the Navico transducer like picture. I figured I could convert it’s analogue signal to nmea and then connect it to my etec I command nmea can. Or replace the transducer with a nmea output unit. With hopes it would just display a depth value on the I command gauge. The lowrance is an old model but reliable, I think it is a lcx12/13 it only has power, nmea and Ethernet plugs on the back. No transducer input.

[Pikey Dave]

Sorry to tell you, but you have under thunked it by a wide margin[emoji6] that's a transducer which is a glorified loud speaker. The head unit sends an electrical pulse to the transducer that converts the electrical pulse into a sonic pulse (that's the "ticking" you can hear when the sonar is working normally) The sonic pulse returns to the transducer which converts it back into electricity & sends it back to the head unit. The head unit measures the difference in time between the pulse it sent & the pulse it got back, does a calculation & voila, works out the depth. All this happens very rapidly at anything from 50-800 times/second. By stitching all the individual depth measurements together, modern sonars are able to give you a "picture" of the bottom. But it's only an interpretation.
So in a nutshell, you need some kind of head unit. I think Lowrance do a basic gauge type that just gives a digital depth readout, it might output NMEA2000, I'd have to look.

[gtflash]

It makes perfect sense. Much appreciated. Just don’t tell anyone I work in electrical electronic engineering or it will be embarrassing lol.

[Pikey Dave]

Originally Posted by gtflash

....Just don’t tell anyone I work in electrical electronic engineering or it will be embarrassing lol.

No problem, my middle name is "discretion".....or is it tw4t? I forget[emoji6]