trim tab analogue sensors, options?

[vas]

hello,

since my arduino programming is impressively successful, lastnight I was listing the things that i'd really want to be able to broadcast on the NMEA2000 network. Trim tabs is one of the most important ones!
I do have some hydraulic tabs from some company that's not in business any more. System works fine, so no probs and reasons to change it.
However, I cannot find some sort of sensor assembly that I can use. My aim is to get some (analogue most likely) data out of the tabs area that I can process and convert to NMEA2000. IF I ever find such a beast (other than the Bennet)

any ideas?

cheers

V.

 

[MapisM]

I'm not sure it's worth the hassle, even if you are confident to take care of the interfacing part.
In fact, the trouble with electronic tabs sensors is rather that they are a consumable item.
All of them fail - it's just a matter of when, not if.

We already discussed the advantage of mechanical sensors in your MiTos build thread.
Then again, on a boat like yours, accurate and reliable tabs indicators are not as important as in speedboats.
'fiuaskme, not bothering with any sort of indicators at all is a sensible option, all considered...

 

[Anthony]

Hi Vas,

My experience with variable resistors under water (Mercruiser trim senders) is that they are unreliable and prone to failure. some form of mechanical transference of the motion to inside the hull (eg a snake cable looped up well above the water line) then linked to a variable resistor would be better. Alternatively the Bennett system uses a steel rod sliding inside a coil but they have the advantage of being fully contained inside the ram.

How about a tube (which could be made waterproof ) filled with a series of reed switches along its inside length and tube passes thru/by a magnet. The reed switches could be in parallel but with each having a different value resistor in series with the switch, thus the resistance would change depending upon the switch that was last, easy to interpret with an Arduino.

Thanks for the email about the N2K, just awaiting some parts to arrive before I can start experimenting.

Anthony