Swimming pools can be a lot of fun, but they can also be quite a bit of work. To help keep things running properly, Luc Brun built a pump monitoring solution that is able to detect the phase shift between voltage and current, stopping the pump if the water level is too low.
While there are other ways to prevent no-water pumping — including a water level detection device that simply fills up the pool, or a water monitor that simply prevents the pump from operating without water — these have a few disadvantages that Brun wasn’t willing to live with. He instead put together a system that keeps an eye on the voltage and current levels to the pump using an Arduino Nano and an ACS712 current sensor module, then measures the offset between the two. For a pump in normal operation, the phase shift will be 25°, while if the pump is running on empty, the shift between the two will be 45°. If an out-of-wack phase shift is detected, it can then cut the water off.
Complementing this phase-shift detection, the also features a RTC module and a DS18B20 temperature sensor that help it to set cleaning schedules, and a Bluetooth module for user interface via a custom Android app. While any pool will require some human interaction, at least Brun doesn’t have to worry as much about his pump!