Xmass Fun – Hydroponics Automation
I’m not sure what the opposite to a green thumb is, but whatever it is, that’s what I have. Any plant I touch seems to instantly die, and I’m tired of it. So I’ve built a hydroponics setup in my laundry room with the goal of full automation such that I can enjoy the plants, but they can be shielded from my thumb-of-death.
I’ve planted Basil, Holy Mint, Cayenne, Cilantro, and Lemon Cucumber — the Cayenne doesn’t seem to be doing anything, one of the Cilantro pods seems a dud, but otherwise, I see some green leaves already! (The cucumber seems to be growing the fastest)..
Now, there are a number of hydroponic setups, and the configuration I’m going with is a container that fills with water and empties based on a timer. The lights are currently always on (2x20W broad spectrum fluorescent bulbs) but they will be migrated to a timer as well with an 18h/6h on/off cycle. Every week or so your supposed to change the water, add nutrients, and modify the pH.
If you ask me, it’s still too much work. So I ordered a cheap pH probe from china off eBay, and built a simple amplifier circuit for it using spare parts. The circuit is pretty basic and I can post it if anyone is interested. I connected it to a board that I had made some time ago but was not being used and added an SHT75 temperature & humidity sensor I had. So far, it just spits out pH (uncalibrated), temperature and humidity readings via USB.
pH: 8.1 (1.44V)
Temp: 67.820 F
Humi: 61.493%
It’s got 10 “switches” built into it that I can use to control things — such as pumps, lights, valves, and stepper-motor controlled syringes that I will fill with nutrients and acid. I hope to get to the point where it will just run by itself, change it’s own water, and maintain whatever environmental parameters that it needs to.
