Hi and thanks for taking the time to read my post. I've been scratching my head a while now, pouring through articles and testing different stuff. I've got a fairly mature aquaponics setup in my greenhouse, 1000 litre fish tank with some carp and then 2 grow beds, one high level that fills and empties using a pump on a timer with a syphon and the low level that I was using a pump with a timer to fill and a sump pump with float switch. I had lots of issues last year with pumps jamming and tanks emptying including the fish tank. I have some experience with software engineering, work in IT for a living and have started training in electrical. I've been 'playing' with the Arduino and starter kits and have come across them as part of the day job so wanted to do something smart. Prior to starting with Arduino I purchased a GZF-12 water level sensor board, very simple high/low sensor with relay to turn on either a fill pump or empty pump. This would do half the job for what I need but I need to fill and empty the lower grow bed on a schedule and also stop if there is a problem. For future improvements I would also like to build in some additional sensors for temp, humidity, light and perform various actions depending on values.
I've been looking at water level sensors for the Arduino but I've not got anything to make one with the bits I have a side from an ultrasonic sensor and with the shape of the tank and the levels of humidity etc this would not be great. I could probably do something really nice with an Adafruit 12" Standard eTape Liquid Level but its £50 when I know I can do something with what I have. I've tested the GZF-12 board and it works, what I've been trying to do is use the Arduino to send a 5v to the common on the board relay and then send an output from the other fill/empty outputs to analogue inputs on the Arduino to attempt to monitor which pump is active. I assumed it would show a 5v from one of the outputs which I could then do some conditional operations on.
The issue I'm having is that my analogue inputs never show 0v even with nothing connected, if I connect the 5v on the board to the analogue it registers 5v most of the time but this isn't constant. If I then try this through the relay I get a similar read when its open of 5v most of time but when its closed I get anything from 0 up to 5v randomly. With these fluctuating values it makes writing code very difficult, I was considering using some averaging of values that I think would work but wanted to float the idea/problem and see if anybody had any better advice. Thanks again for reading.