This project is part of a full home automation solution implemented on our residence. The design shown here has 8 stations with no humidity feedback, which is quite sufficient for most residential projects. It can be expanded to up to 64 stations for commercial installations.
If no humidity feedback is required, the cheapest solution is to use the 8-Relay Expansion Card (available soon) This stackable card for the 40-pin Raspberry Pi family packs 8 relays in the same form factor with Raspberry Pi.
Humidity sensors are cheap and can provide a water saving solution in regions where there is a shortage of water, like California. The Mega-IO card (available now) has 8 analog inputs, which could read the humidity from 8 irrigation zones.
Each Friday is PiDay here at Adafruit! Be sure to check out our posts, tutorials and new Raspberry Pi related products. Adafruit has the largest and best selection of Raspberry Pi accessories and all the code & tutorials to get you up and running in no time!
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.