What’s up ya’ll? So when I first started looking at automating some of my grow, I experienced a good deal of sticker shock when I started looking at off-the-shelf controllers. $3K plus for a base model Agrowtek? I’m thinking damn, there’s only $300-$500 worth of off-the-shelf components inside….. Their engineers and/or sales staff must get paid very well! After the sticker shock subsided, I decided to draw on some of my engineering skills and started putting together a BOM to build my own simple “switch flipping controller”. BOM is listed below. I’ve also a link to the software that powers everything. You’ll need to register an account on mydevices.com.
I realize some may not be so tech savvy but here’s a generic overview of the process. Once an account has been created, you install the Cayenne app on a mobile device. Next you register your RaspberryPi to you mydevices account. Once your device is registered, you’ll be provided identifiers to include on you Python script that runs on your Pi. After all that’s said and done, you’ll need to configure which Cayenne channels correspond to the IO pins on your Pi. Once channels have been assigned to IO pins, you can start adding buttons, schedules to your individual relays.
Bill of Materials and approx costs:
- Blue project case – Amazon ~$40
- CanaKit Raspberry PI (model 3 b+ if memory serves) – Amazon ~$60
- StandOff kit Amazon ~$17
- Relay modules – Amazon ~$21 (enough to toggle 12V solendoid valves)
- Misc 16ga stranded wire – local hardware store ~$10
- 12V power supply – recycled from old electronics (needed to power the solenoid valves when relays are engaged)
- 5V power supply – recycled from scrap parts (needed to power the Raspberry Pi and logic boards of relay modules)
Here’s a description of the plumbing:
- 3 elevated 50 gallon barrels with bottom drains that connect to a solenoid valve
- the 3 drain solenoids attach to a manifold
- the manifold connects to an on demand RV water pump
- The RV water pump connects to a manifold with an outlet for each row of plants
- Each outlet has a solenoid valve attached to an irrigation line
This allows me to feed any row from any barrel (1 with bloom nutes, 1 with veg nutes & 1 with water only) so long as scheduling doesn’t conflict.