I'm in the process of setting up a hydroponic system for growing basil, chilli and parsley, and it's going to be Arduino automated from the ground up. It will have CO2 detectors, pH meter, water level sensors (pressure transducer in line with an air pipe), and lots of solenoids. That's the easy bit, there is heaps of example code at http://www.arduino.cc/ and a board with lcd/breadboard/psu/extras $80 or so.
The hard part is the EC/PPM/TDS sensor. You would think it would be easy, just drop a couple of wires in and measure the voltage drop? It's not quite that easy. DC builts up a residue at the electrodes, so you have to use AC, i.e. you can't just plug your electrode into the analog input on your microcontroller. That's ok though, there are interfaces you can buy. I'm still scoping out the best one, would be interested if anyone has done anything similar?
Anyway the best part of the system is the nutrient automator.
I think nutrient regulation is one of the best uses for microcontrollers in hydroponics. I'm planning on having 7 resovoirs containing the ingredients of the http://en.wikipedia.org/wiki/Hoagland_solution. When you place any quantity of dry KNO3 in the tank, the system will detect the weight increase and add the right amount of water. It then mixes these nutrients in proportions controlled by solenoids into 4 seperate resovoirs, eg veg/flower/seedling/whatever (software controlled).
It could facilitate a scientific comparison of the performance of different nutrient formulas.
I'd be interested to see if anyone has tested their formulas in this way, and can recommend some starting formulas other than the hoagland solution. Btw first post, obviously I don't have all the answers just yet so I'm looking forward to learning from some of the advanced growers on this board.
The hard part is the EC/PPM/TDS sensor. You would think it would be easy, just drop a couple of wires in and measure the voltage drop? It's not quite that easy. DC builts up a residue at the electrodes, so you have to use AC, i.e. you can't just plug your electrode into the analog input on your microcontroller. That's ok though, there are interfaces you can buy. I'm still scoping out the best one, would be interested if anyone has done anything similar?
Anyway the best part of the system is the nutrient automator.
I think nutrient regulation is one of the best uses for microcontrollers in hydroponics. I'm planning on having 7 resovoirs containing the ingredients of the http://en.wikipedia.org/wiki/Hoagland_solution. When you place any quantity of dry KNO3 in the tank, the system will detect the weight increase and add the right amount of water. It then mixes these nutrients in proportions controlled by solenoids into 4 seperate resovoirs, eg veg/flower/seedling/whatever (software controlled).
It could facilitate a scientific comparison of the performance of different nutrient formulas.
I'd be interested to see if anyone has tested their formulas in this way, and can recommend some starting formulas other than the hoagland solution. Btw first post, obviously I don't have all the answers just yet so I'm looking forward to learning from some of the advanced growers on this board.