Looking for advice on well water level project

Hello everyone,

new to this forum, I have been messing around with Arduino toolkits for a bit, and have some basic understanding of electronics and some equipment. I worked with pre-built kits, building electronic projects based on tutorials and I love repairing old electronics.
But never found a problem that I needed to solve with an Arduino. Well, that is until now.

I would like to measure the water level in my water well. It is around 5-6 meters deep and the water level is somewhere around 1-2.5 meters. I thought this would be a neat first real project for the Arduino Uno that I have laying around, as I have had some problems lately with low water levels and an quick and easy way to check the water level would be great.

Since this is my first real project, I would like to ask this forum for some feedback and advice, mainly on the hardware side. I haven't really looked exactly how the coding would work in detail, I know that there are tons of great resources for that, but I want to take it one step at a time and right now I need to order all the components that I will need. I also created a simple diagram, I hope my mspaint skills amuse you :slight_smile:

  • I have an Arduino Uno that I would like to use to read the output signal from the water level sensor, using an analog in pin.

  • As a water level sensor I would like to use a QDY30A. The sensor is powered by 24V DC and can measure up to 3m water level depth. (
    There are different version of the sensor, seems like the industry standard for such sensors is to output current based on the pressure reading (4-20mA), from what I understand due to the fact that it is realiable and does not drop over longer cable distance, like voltage would.
    As far as I know the Ardunio cannot directly measure current via the Analog In Pins. There are differnt ways to get around this, including an external circuit board that would first convert the current reading into a 0-5V reading that the Arduino could then use.

However, the QDY30A water level sensor can also be purchased as a version that outputs 1-5V voltage instead of current. I would prefer this due to simplicity. I think this might work just fine for my case, as the total cable lenghts will be less than 10 meters.
I already have the data sheets for the sensor and I am also attaching it.

  • To display the water level, I would like to use a generic 7 segmet display that was included in my Arduino toolkit. I think this is similar to a 5641AH. No idea how to hook this up yet, but I am willing to learn :slight_smile:

  • As a power supply, I am looking at a Mean Well Switching power supply, 35 W, 2.2 A, 5/24 V. This outputs both 5V to Power the Arduino and 24V for the water level sensor. I would also combine it with the power supply with a power switch with a fuse. I think that the 35 Watts of the Power Supply will provide plenty of power for both the Arduino, the 7 segmet display and the sensor, however there would be more powerful versions with 53W or 68W available if needed. I do understand that I need to use proper cable diameter and crimp the cable connections.

Furthermore, my idea is to design a custom 3d printed case to hold the Arduino and other components and to mount this case in my garage, in a dry and save spot. The water level sensor is permanetly mounted at the bottom of water well and connected to the Arduino,I can use an existing pipeline that connects the water well and my garage for the cable connection of the sensor.

In my initial design I would only switch the unit on when I want to actually read the water level, and turn it off once again a few seconds later. So the components would be without power connection 99% of the time.

In a future step I am thinking to log the water level data somehow over a longer time period. I think this would need to permanently power the components and also invovle some wifi connection, but I have a pretty bad wifi setup at home, so for now I would just skip this part, maybe add this feature later on.

If I could get the approval from someone that has more experience for building such projects, that would be really awesome. Maybe I am also missing components like resitors, etc. or potentially there are improvements that could be implemented relatively easily that I didn't even think of.

Thank you for reading, I wish you a great rest of your day!

What you propose looks and sounds fine, and there are a lot of projects around here like this. Many use 4-20mA and the peripheral circuitry for that is pretty simple. I think you would be better off with a common cathode 4x7 display and a MAX7219 to drive it. It will surely make life easier.

Since you already plan to use 240v, it doesn't matter how short or long the duty is, and the power supply is more than adequate for the additions you propose.

Using Bluetooth or Ethernet may be worthwhile options. About the only other consideration is using an SD card - for when the other stuff fails.

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Awesome, I will definetly look into your suggestions. Thank you so much for your reply, it means a lot to me!

I cannot add anything useful except to say that this looks like a great project for someone relatively new to Arduino. Your basic approach seems spot on. I also support @Nick_Pyner's idea of adding functionality, bit by bit, after you've got the basic measurements working. That is the right way to handle a project - we get lots of newcomers who've never built anything with an Arduino trying to eat an elephant in one bite. Usually it's some code they've downloaded from the Internet, and they are completely at sea when it doesn't work.

I hope you'll keep us up to date with developments. :slight_smile:

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This concerns me greatly! Are you suggesting you will run the wires inside the pump sucker pipe?

It doesn't sound such a bad idea. If OP has thought about it all, he/she has probably thought about the implications of what you do at each end..

If that sounded like there would be any water in the tube, no that is not the case.

The idea is to run the sensor cable through an exististing installation tube, it connects my water well with my garage.
There is already another power cable in this installation tube for powering the garden pump (which runs for max 45 minutes per day in the spring and summer).

Potentially the water level sensor's reading might go crazy when I power on both devices at the same time? I don't plan on doing that.

I could drill some new holes between well and garage specifically for the sensor, but it is all concrete and brick wall, so I will try to avoid that extra work if possiblie.

Besides that, today I ordered all components. The sensor will take 2-4 weeks for delivery.
Also, I played around with some example code for the 7 segment display connected to a thermistor, which helped a lot.

I really look forward to receiving the components and start working on the project.
I will update the thread with the progress :slight_smile:

Do you mean you have a submersible pump with such a shallow well? Please do not ever run data wires adjacent to power wiring!

That's a ridiculously sweeping statement. My ethernet works just great in the same duct as mains cabling.

Yes, I am using a GARDENA 6000/5 Automatic 1476-20 Submersible pump. I connect it to a power outlet in my water well.
This power outlet is actually connected to a timer switch (the timer switch is in the garage, before the water well), so the cables aren't powered most of the time. Does that matter?

And in my first version, the Arduino & sensor will only be powered when I want to check the water level. Also the seller told me that water level sensor cables are shielded.

Let's say I want to run the Arudino and sensor permanetly and log the sensors data automatically. Google says that I should have a distance between the two cables of 50mm, would that be sufficient in your opinion?

Thanks you did a great presentation of your project. Seriously consider using something in the 7-12V range to power the Arduino via Vin, this will give you added stability and noise protection because of the additional on board filters etc. I expect noise etc from the associated well pump. Just a note, schematics are much easier to read then frizzy things that leave lots of important things to the imagination. Other then that you are spot on!

But not with a powerful AC motor starting and stopping!

Only when the motor starts and stops!

You are making a bald assertion, without providing evidence. A lot depends on the type of signal cable, whether the signal transmission line is balanced or unbalanced, screened or not, and so on. Also, on its operating frequency.

Honestly, you just don't know enough about the OP's setup to know whether it will be a problem or not. It is certainly possible there will be problems, but you are quite wrong to suggest that problems are inevitable.

Sorry, but good engineering is to limit the possibility of problems when there are conditions that have caused problems in the past.

Anyway, I'm sure the OP's got the message. :grinning:

Hi there, I'm a Hydrogeologist and I'm thrilled with this project! It is literally what I do for my Job. If you want to get fancy, you could incorporate a Barometer into your arduino and have it subtract air pressure from the readings. This offsets any impact weather/pressure systems have on the water level and cleans up your hydrograph.
I also just want to make sure I understand your installation. In your well, there is the main outer casing, then there is a narrow water return line that is attached to the pump at the bottom, and the power cable that goes down the well. You're planning on just lowering the pressure transducer down the main casing, till it is submerged? One problem we run into is the pressure transducer likes to wrap around the return pipe line and get stuck. Fortunately your set up is so shallow you could probably lift the pump out by hand.

Would love to hear more about how your project is going!


Hey @d3s3rtcr4lr. I am still working on the project.

I received the QDY30A water sensor a few days ago and was able to work on the code for the Arduino to show the water level on the display, I am quite impressed how well the sensor works.
Thanks for your ideas and suggestions on that.

Our water well has a diameter of one meter and actually there are currently two water pumps in it. One is used for our water to water heat pump, which drives our hot water tank as well as our floor heating system. The second water pump is used for watering our garden (plants and lawn). Each water pump uses their own water tubes and electric cables. And you are right, I plan to submerge the sensor all the way. I think there should be enough room to run all cables and hoses so that they will not get up messed up, as it is a quiet envoriment :slight_smile:

This is my current to-do list:

  • I would like to switch from Arduino Uno to a Nano to make the casing a bit more compact. I have a chinese Nano clone that uses a CH340 chip but I cannot get the driver to work, my PC currently does not recognize the Nano at all. I tried to reflash the Nano and re-installed the drivers many times. Probably this is a hardware issue with my PC, tomorrow I will try to get this to work on a different PC. Otherwise I will just go with the Uno.

  • I also want to replace the display that shows the water level from a 7 segment display to an OLED I2C display, as this requires only 4 cables to the arduino instead of 12, which makes the wiring a bit cleaner inside the housing.

  • Then I will start the design of the 3D printed case which contains the Arduino, the power supply and the power switch as well as the display.

  • Once I have accomplished this, I will start drilling the necessary holes, run all the cables needed, installing the housing in my garage and mount the water sensor in the well.

  • Then I plan on sharing pictures of the installation and providing the source code in this thread, in case someone else is interested. This is the least that I can do to show my appreciation on all the great help I have received so far. :slight_smile:

Maybe bite the bullet and get a Nano from a more expensive supplier.

Yes, spent way too much time trying to fix this, so I wouldn't recommend buying a clone Nano at all.
Today i visited our biggest electronics store in the area, but they did not have any Nano in stock, only Unos. Might pick one up online, or just go with the Uno and a slightly bigger case.