I am using an Arduino board with in-built ESP8266 for my wifi connected EmonTx shield
Once I get that project operating, I would like to automate my water tank level reading (We live on rural acreage, relying on rain water). The idea is to feed the data to EmonCMS (private server), then use that data, as well as solar data to control pumps to move water. I want to have all connected by wifi for ease of use.
There are heaps of designs on the web for Arduino shields using ultrasonic transducers to measure water level (so no need to re-invent the wheel!), but there will be work required for the ESP8266 communication. This project will be powered by a small solar panel & Lithium Ion battery (because you do not want to climb a 7.5M water tank tower very often!). The best Ultrasonic sensor to use is the waterproof one available from AliExpress (& others) for a few $. (These are used on cars for parking sensors as an example)
A suggestion to the developers of the ESP8266 code is to allow bi-directional communication. I would also like to use the ESP8266 as a load controller (using a Solid State Relay) to switch on pumps for this project.
Eventually, I would like a fail-safe control system (possibly running on the EmonBase) to check levels while transfer pumping to ensure everything is OK. Living on Rainwater you cannot afford to lose water!
If anyone wants to start this project please keep me informed. I think it is applicable to the Emon project because water is another sustainability issue. Also this project could monitor other data, such as a hopper for an auto-feed boiler (using woodchip for instance).