Hello From Idaho, US.

@datashuttle, Welcome to the forum!.. You'll  find many on there with diverse skill sets in both hardware and software, and a fair amount of noobes as well! We are all here to learn and share our experiences and projects, hoping to enhance our knowledge and skills. Let us know what interest you, and what projects you are currently working on..

kind regards,

LouisR 

Thanks for the welcome. I'm interested in working with microcontrollers with various sensors. Most of this, at least for my needs, I'll be able to figure out. The code part is the easy part for me.

The more challenging part is identifying what sensors are available to implement what I want to do. For example, I have a custom offroad camp trailer that has a fresh water tank, and I'm looking for a sensor that can return water level data. I'm open to ideas. 

@datashuttle You did pick the hard one. See what boats use, we know the RV industry does a horrible job. SeeLevel has a better solution but I had 1st gen and they didn't work for me since I had too much steel in close proximity.

Hello Ron. Now if you are as cute as that puppy, you are indeed a handsome dude!!!

So I assume the SeeLevel sensor was magnetic? Could you elaborate on your misfortune with it? I'll look into it on my end.

@datashuttle Pretty much the inverse of the pup. Not magnetic, the sensor is glued onto the outside of the tank and mine were too close to the frame. I was 80 at the time and couldn't manipulate my body into a position where I could install them somewhere away from the frame. Many do use them, in fact some of the higher end RV's factory install them.

I have no idea how they work. They connect to the old wiring so there may be power involved, and the fact the frame affects them tells me either magnetic field or electrical field. 

Good luck.

@datashuttle I am fairly sure you know this but just in case, no sensor returns water level, they just return voltage and the code interprets that. 

Since you mentioned offroad, then none of the 'static' sensors will likely work. These are typically mechanical with resistive sensors. Some have attempted ideas such as shining a light off the surface, acoustic sensors and for water of course the RV style that can work if you install enough but you have to penetrate the tank.

Unless your tank is different, all RV tanks are very thin in the Z direction which means the depth of water is shallow and changes slowly. This is the least desirable situation. Farm tanks are static, and taller so a simple float based system, or acoustic or reflected light all work quite well.

If the shape and location of your tank is such that you can insert a hollow tube through the top that has a float like in some toilet tanks, and maybe use a Hall sensor (I just now thought of that so it's very experimental).

Here is a description of a Hall Effect sensor

A Hall effect sensor is a transducer that varies its output voltage in response to changes in magnetic field. In some ways, Hall effect sensors can ultimately perform a similar function as a reed switch, but with no moving parts. Think of it as a solid-state component, good for digital applications.

Attached is a type of plumbing fixture that might serve as the germ of an idea how to use a Hall effect sensor. I do NOT think that one sensor detecting distance will work, I am thinking more along the lines of several (4 for 1/4's, 5 or more is even better, ideally maybe 5, 7, 9) and then the NANO or ESP32 or even ESP8266, and maybe the really small ESP's with numbers below 12 as long as they have WiFi or BT code can determine the strongest signal and if you get crazy integrate the next closest two, maybe even more to fine-tune the % full. Since the MCUs have WiFi and in some cases, Bluetooth no wires are needed, just a coin battery with wires routed to a convenient location. Use deep sleep and wake up on an RTC scheduled basis of maybe once per 15 minutes. You could even use a motion sensor to gate the clock, if no motion is detected for x minutes, defer the wake-up.

Now I wish I wasn't selling my RV so I could build this.

@zander

@zander, @datashuttle, Ron..Yes you are correct, the electric field of the SeeLevel system is a type of capacitance sensor, utilizing the difference between the dialectics of Air and liquids.

@datashuttle, Here's a link to the various types of RV tank level measurement devices that are typically installed in Rv's..

https://www.thervgeeks.com/rv-holding-tank-sensors/

I Hope this information helps you with your project..

regards,

LouisR

@inst-tech @datashuttle Yes, I know the RVGeeks well. FYI, geek in this case is more akin to Fan Boy. It would appear that the SeeLevel is a form of the second type they mention that are called 'Electrical Resistance' sensors but in fact work like Louis said. I heard that SeeLevel has a new version out but I can't tell you much about it. The parent company is Canadian based in Alberta with another office in  TX. I have talked to head office a couple times and found them very approachable and helpfull.

If you have the right size tanks, and an interference free place to mount them, I would definitely recommend them.

@zander Yes, I have understood variable voltage is how the data is presented.

In this case, I was hoping to discover something that didn't require tank penetration for two reasons, one, the inside components are subject to calcium deposits, and, two, I would have no way to extract the components without removing the entire tank.

I've even considered a decidedly low tech, but effective, sight glass sort of arrangement, but have elected not to go there for other reasons.

I'll look at the SeeLevel stuff and see if there is anything new there.

@datashuttle I was thinking of the low tech sight glass but that does require tank penetration. If you ever need to do something like that, go to a marine store or even a well stocked hardware store and look for marine grade through hull sealants, I think 3M has one called 5200. I used it to plug a hole below the waterline on my boat and it never leaked a single drop.

@zander So I took a look at the SeeLevel sensors on this site: https://shopusa.garnetinstruments.com/solutions/holding-tanks/710-es2-710-es2-12-sender, and that is interesting. Now I wonder if it could be made to work with an ESP32 WiFi controller.

I'm trying to setup all the sensors I'm using to respond with JSON payloads via WiFi, and build a local web page that provides all the data from all the sensors I need on a single page. I'm trying to eliminate all the proprietary apps and want everything at a glance. This is easy and how I get my kicks, just need the sensors, and I have most working, just not the water level detection.

@datashuttle I think the SeeLevel will be a problem in that case as this is proprietary hardware and software. I think though they have a new version that works with a BT to WiFi hub that an ex RVer sells. By all means ask, but I won't be surprised if they are not interested.

Found it, here is the HUB link (RV Whisper), you can connect a lot of stuff through this https://bityl.co/NyHk

and here is the link to the SeeLevel uit that works with RVWhisper https://bityl.co/NyHq

@zander That's interesting and will look it over.

I'm trying to stay away from Bluetooth as I need the data beyond the typical transmission range, and reliability, of Bluetooth, unless I can bridge to my network and WiFi.

I have four Victron Bluetooth sensors that work with the Victron app, but I cannot see the Bluetooth data unless I'm standing outside the trailer next to the transmitters, which makes them marginally useful. So, I'm looking for some type of Bluetooth to WiFi bridge so I can get that data over the LAN. Something to receive the Bluetooth at my router, which is close to the transmitters, and make it available on the LAN.

I travel with an Intel NUC in the tow vehicle, and it's very capable. My router is very strong as well, so just need to get everything available on the network and I'll be okay.

@zander That RV whisperer device is very similar to what I'm building, except having an app and making cloud data available, which is not needed as I'm often off the beaten path and way beyond cellular internet. Perhaps if I can come up with a way to consume the Bluetooth data, then put it on the LAN, I'd be okay. It looks like his device is storing data on a SD card or Db, then making that available as needed, which might be a good idea.