Looking for cheap Arduino Rudder Angle sensor

[ian5142]

Hello All,
I am looking for a relatively cheap (<$50) rudder angle sensor. I would prefer not one of those 0-190 ohm Aliexpress ones. https://www.aliexpress.com/item/1005002118775085.html


This one looked better: https://www.aliexpress.com/item/32825256935.html


Non-resistance based would be even better but may not be in my price point.



I don't need the gauge because it is being fed into an Arduino to create a NMEA sentence to send to OpenCPN.

[stormalong]

Why not make one? Why don't you want a resistance type.

It is just a potentiometer (variable resistor) with an arm attached. Put a voltage across the potentiometer and read the voltage at the brush. The Arduino can read the voltage which will be proportional to the arm position.

[ian5142]

Originally Posted by stormalong

Why not make one? Why don't you want a resistance type.

It is just a potentiometer (variable resistor) with an arm attached. Put a voltage across the potentiometer and read the voltage at the brush. The Arduino can read the voltage which will be proportional to the arm position.

First off, it must be waterproof. My steering compartment is almost always wet.



So far the voltage ones that I have seen do not have enough of a range for my liking, ex: 1-190 ohm is not very much range. If I was going to build one with a pot, I would use a 10k pot. I know simrad uses frequency feedback, ex: RF300 unit.

[wholybee]

Originally Posted by ian5142

First off, it must be waterproof. My steering compartment is almost always wet.



So far the voltage ones that I have seen do not have enough of a range for my liking, ex: 1-190 ohm is not very much range. If I was going to build one with a pot, I would use a 10k pot. I know simrad uses frequency feedback, ex: RF300 unit.

If you connect the pot as a voltage divider, the value doesn't matter. A 200ohm pot will work the same as a 10k pot. But the 10K pot would be more susceptible to noise, example interference from an SSB.

I think you are asking for something that doesn't exist, unless you build it. Rudder Sensors are simple and expensive. The expense I think comes from durability, both being waterproof, and able to survive several million cycles. Most pots will fall apart with that much use. You are asking for a cheap one, that is more sophisticated than what is currently available.

[JeffBurright]

FWIW, I have one of the cheap ones you linked installed in my laz to support my ESP32 autopilot. I don't have the same water ingress problem, but I wonder if you could build a better housing to combat that problem. You also got me thinking about the "build your own" route. Could you rig something up with hall effect sensors to create an angle indicator?

Also, I recall the ESP32 has a hall effect sensor built into it. Could you build some kind of rig for the ESP32 itself to have it report its position relative to a magnet? (https://randomnerdtutorials.com/esp3...effect-sensor/)

Otherwise, it looks like you have to spend around $200 for a proper rotary hall effect sensor like the commercial units have. By that point, you could burn through 10 of the cheapos.

(Note: the photo is not the final installation, but close enough for illustration purposes)

[wholybee]

The do have magnetic encoders which operate similarly to a pot but without the moving parts. But it isn't a direct replacement and requires circuitry to drive it. So it becomes more sophisticated and expensive.

I recently printed this but didn't assemble it yet. I expect whatever pot I use will need occasional replacement. Grease is supposed to keep it waterproof.
https://www.thingiverse.com/thing:4767032

[bdbcat]

If you need super precision, and don't want a POT, try this:


https://www.amazon.com/dp/B08TTJTWLJ...roduct_details


I used one to build a wind direction indicator, interfaced to Arduino. Nice.


Dave

[Bellinghamster]

Use a rotary encoder. Some types are only used relative rotational change and direction, i.e. need to be "calibrated" to a known positition each time and can't recover from a "skip". Some are absolute position. A quick search turned up this one that looks like it fits the bill.. and with digital communications rather than analog voltage level so less susceptable to noise (to a point!): https://briterencoder.com/product/ip...olute-encoder/