I am currently trying to measure the water level in a well. The depth of the well is 15 meters, and the water level can vary from a few centimeters (when almost empty) to 11 meters (when the well is full). I expect a minimum accuracy of 5 cm.
I know this subject has already been discussed here, but the solutions I saw do not look good to me.
I am currently trying to do this measurement with a ms5540c sensor.
The communication with this sensor is pseudo-SPI. In my experience, it is not possible to communicate with SPI over long cables. Thats why I chose this architecture for my project:
I am reading the pressure at the bottom of the well with a ms5540c sensor, and comparing it with the air pressure at the top of the well (taken with a BMP280 sensor) to compute the water level.
In my tests I got an accuracy of 2 cm. This seems really not bad!
The problem I have is that this system worked for 2 days. After these two days, I could not communicate with the ESP8266. I took a look at the board and saw that the voltage regulator was fried. I believe there was a short circuit somewhere underwater: (Arduino pro mini or MS5540C, or the ethernet cable).
The arduino pro mini and the MS5540C were made waterproof with a bi-component epoxy glue.
So now I have a few questions: -What is the right way to make this kind of sensors waterproof? -Can I use ethernet cable underwater? If not, what should I use? -What am I doing wrong?