After a bit of playing about I’ve got my water level sensor working 🙂
I’m using Munin to log the data coming back from the unit attached to the sensor.
The unit is overkill for my needs, but since I had it lying about here and I didn’t want to spend anything to do this job it’ll have to do 😉
It’s a nice little PIC based board with 4 analog inputs, 8 digital inputs and 8 mains switchable outputs.  It also has an ethernet adaptor and the software I’m using responds to modbus commands.  I’ve had fun getting everything working.
I’d forgotten how much fun it is to make computers actually do something in the real world!