So, im keen to know if anyone has interfaced with their water tanks. I want to monitor two 30,000L tanks, but am having a hard time find the appropriate hardware to get the job done.
We have 3 tanks, the plan is 3 senders, attached to a ESP32 on wifi.
The problem is, finding a sender that can go deep enough to monitor a 30,000L tank.
Any ideas / recommendations from anyone who might have done this?
Thanks
I donot have this sizeable tanks but read about this a while ago…
Ultrasonic Sensor - HC-SR04 - Hardware - Home Assistant Community (home-assistant.io)
Thanks, yes it looks like ultrasonic is the only way to go with tanks this size.
Im looking something sort of off the shelf, ready to go like this. Has anyone used one of these or reverse engineered it with a ESP32?
Ultrasonic Water Tank Level Meter with Thermo Sensor | Trade Me Marketplace
Thanks again!
give up on ultrasonic. they fluctuate too much and have issues with moisture. yes even the ‘waterproof’ ones.
go read the posts on esphome water level sensor.
specifically ones from hummingbear and quizzical.
a gravity throw in sensor is the go.
pat
Not sure I really agree with this comment, moisture issues should really only be specific to a certain vendor.
I know specifically as ultrasonics are used reliably in very large industrial facilities.
Brad,
I guess i’m going on my first tentative steps with ultrasonic sensor. I kept on reading that values would fluctuate based on temperature and air moisture level. I am in a sub tropical climate and know that the air inside my rain water tank is very moist for about 9 months a year.
I know I made my decision based on other opinions but their data appeared to show that ultrasoinc didn’t rate when compared with thrown in pressure (or externally connected pressure) sensors.
My introduction to the world of electronics and HA was based on trying to find a home grown solution to a busted tank water level meter from Gallagher equipment.
I’m learning and I’m happy to be shown a good working example of an ultrasonic sensor showing accurate water levels in an external plastic 22000 litre tank in my sub tropical environment.
I have yet to find a write up about one that shows consistent (over two years) use.
Pat
I agree ultrasonic sensing isn’t ideal; I gave up after a couple of failed attempts. One pair failed after a few months, the second set developed blisters on the front surface and wouldn’t read consistently.
Failures aside (and bear in mind I’m using the domestic - ie. cheap - sensors, not the industrial quality which I’m sure would perform better but probably cost more than my 4000L tank) the air temp / humidity inside the tank gives you +/-10% readings or greater during a typical daily temperature cycle.
If using ultrasonics you need to put a lot of constraints on your readings: if your tank top is flat and gets a good moisture film, you can read 2x the distance to the water surface and end up with negative values; if you have a top fill entry point, all readings will be messed up when there is water entry and the water surface isn’t smooth. Sure you can overcome all these issues, but I ended up with a very complicated set of filters and lambda’s to get sub-par results.
I don’t know if waterproofing failure is necessarily an issue (mine were the waterproof type, surface mounted to holes in the tank top), the technology is just not a great choice for reading distance from a water surface.
I then tried the HX711 pressure sensor (same as a washing machine, place the sensor above the water level then drop an air filled hose into the tank) which works OK, but air temperature in the tube still causes +/-5% readings across a day.
I’m currently trialling a pressure transducer (industrial build) which connects into the outlet pipe (yeah I know a bad idea - very low readings when the pump is running - but was easiest to fit a tee and test it) but having trouble with linearity of ADC readings on the ESP32 module I’m using.
Based on what others have experienced I’ll probably end up with a drop-in type pressure sensor (buy one to read 50-100% greater water head than you have, you can get these from around USD25 on aliexpress), 4-20mA current loop type, and a current loop > Voltage conversion module to read it on an ADC.
So these only read between 50 - 100 %? If i read that correctly?
No, sorry that was poorly worded! They should read the full 0 - 100% for you. Depending on the type you might need 5V to power it. If you’re using the Wemos-style ESP8266 or ESP32 boards you have a ~3.2V limit on the ADC. So you will either need an external resistor dividor OR get a sensor that will only be at maybe 80% of it’s maximum range when your tank is full.
I did the latter; my transducer has a 5 PSI limit, my tank is 2m tall which is around 2.8 PSI so the maximum V I’ll get for my ADC is 2.8V (well below the 3.2V max). You sacrifice resolution doing this, but I only care to the nearest 1%.
Yea thats not the end of the world.
So what are you using now? One of these?
Pressure Transmitter Oil Water Level Sensor Probe Detect Controller Float Switch | eBay
Also, I noticed none of these actually come with an ADC or am I looking in the wrong place.
Any recommendations much appreciated! Im going to have to play the long waiting game none the less as none available locally for me.
One of these (5PSI variant): 5v 1/8npt Oil Fuel Air Pressure Transducer Transmitter Sensor 5/15/30/60/100/150/200-1600psi - Pressure Sensor - AliExpress
If you go down this path, be aware the “1/8NPT” thread is a tapered thread so you can’t readily tap something and fit this in - I wasted hours finding this out. I fitted min to an ABS plastic Tee fitting and used the transducer to cut it’s own thread which makes it tight and waterproof. I fitted a baffle with a pinhole in it to minimise water flow pressure changes, but this isn’t good enough.
None come with an ADC, but your ESP32 has enough. Connect each sensor to a different ADC on the ESP32.
Oh damn ok thats good to know! Thanks!
Thats super cheap, will that sensor measure the pressure of a 30,000L tank?
Compared to the sensors im looking at, this is so much cheaper.
Multiple float switches will give general water level; full, 3/4, 1/2, low. Available readings are based on sensor count.
You can do same with multiple water sensor
Both those are available off the shelf
so one of these is fine.
The only reason is its just ready to dip the way it is. Way easier then playing around with trying to seal and waterproof it
Should do it - very easy to install, that’s the kind I’m thinking of trying next.
If you want to connect to your ESP32 ADC you’ll also need the current loop > voltage converter, something like this: 0/4-20mA turn 0-3.3V5V10V Voltage Current to Voltage Module Converter Signal Generator | eBay
Dean, That’s the one I’m using. i bought from an Oz supplier and it came with the current to voltage converter. I have sent this signal through an ADS1115 though as apparently the ADC on the ESP32 is not real flash. Everything will be powered off a 5v supply with the sensor receiving it’s power from a dc/dc step up.
Have nearly finalised my bench testing and will be putting it into a box and throwing the sensor in my tank this week I hope. I have read that for the first two days I should have the sensor out to get my ‘empty’ tank reading calibrated. My tank is a 22000 litre and is located about 30m head above my house.
I fully intend a proper write up as this project has taken me nearly 4 years. I kept getting sidetracked into other brilliant integrations in HA.
Pat
Patraff, sounds good! I think im going to bite on these then.
Any chance you could link me to the one you bought as many that im looking at dont have the current to voltage converter.
I look forward to the write up!
Thanks
I got mine from core-electronics. It’s a bit pricier than just buying off ebay. I reckon they might both come from the same supplier. Here’s one on ebay that looks exactly the same AU Submersible 0-5mH2O Water Level Transmitter Liquid Transducer Sensor 6 | eBay
You’ll find the current to voltage converters cheaper on ebay as well.
Pat