So I started a new personal project in the past week or so. I built a very crude hydroponics setup using old Gatorade bottles and a Ford windshield washer pump to push nutrient-water through the system from a 2L Coke bottle as the “reservoir”. Ghetto. As. Hell. You can check out pics of it here: http://www.flickr.com/photos/nemik/sets/72157622608195083/

So I thought it would be cool to automatically control all this via the Arduino. I built a simple little circuit to control the pump so it runs for a few seconds every 10 minutes. However this could be expanded further so that the entire hydroponics setup can be automated via a computer that talks serially to the Arduino.

The Firmata (http://firmata.org/) firmware is designed to let a host computer talk to the Arduino in this way. So I modified it a little to for the project. It can use the Firmata functions of reading analog pins to get sensor readings but I wanted to have critical functionality like the turning on/off of the pump at specific intervals to be under the Arduino’s control. Just in case the host computer crashes or a connection is lost somehow, that a critical part of the plant’s needs such as water does not break as well.

The project is hosted here http://github.com/nemik/arduinoponics and licensed freely under and MIT license.

There is still a lot of work to do here. I should post schematics for my setup first I suppose. So I’ll do that once I find a decent software in Mac or Linux that can draw schematics, never done this before. Also, I need to write host-software for the setup. I have a FON2100 Linux modem running the OpenWRT firmware and it has the Lua language on it. I’ve never used it before but it doesn’t seem too hard. I’m thinking to maybe write a Firmata implementation for Lua (probably based on the existing Java one used in Processing). I already got it talking serial to the Arduino so it might not be too bad. Or I could just use an old laptop and then maybe modify some existing Firmata host software rather than have to make the Lua one; I’ll have to see. The Fon router is just attractive now because it comes in such a small size and runs off 5V so it could share the power for the Arduino. Provided the 12V adapter I’m using for the pump and 7805 regulator to the Arduino can handle all this…it’s only rated for 1A. I may have to get a larger one.

Anyway, let me know what you think. I would love suggestions for this.