Last year I decided that I needed a better (easier / lazier?) way to control watering around the farmstead. Did I ever mention that we have an Urban Farm? See here ... https://www.facebook.com/3acresandabarn/ 
 
Back to our regular program ... So I purchased a couple of inexpensive Orbit water valves with timers, and did what any self-respecting engineer would do ... I gutted them! Seriously though, I removed the Cypress MCU that was on the board and swapped in an nRF51822 BLE part (via an rfDuino RFD22301 module). After al little coding on both the Nordic part and a complimentary iOS app, I had a remotely controllable water valve. Sweetness. 
 
This year (2017) I plan to go all out with the Farm-tronics stuff. I have a camera setup ready to go for the chicken coop (RPi and camera), and several soil sensors ready to go into our various garden beds. Not 100% sure how all of this will come together in the end, so stay tuned. We'll use these water valve for some drip / soaker applications to better control moisture in the beds. 
 
Pics... 
 
Front / outside... 
 
 
Rear / outside... (dark gray portion is the battery holder ... 2AAs) 
 
 
Inside (water valve on the right is a latching type so there isn't a constant high-level battery drain)... 
 
 
Closeup of the RFD22301 module and my 4 pin programming port. I do not use DFU (partially on purpose), so I need a way to program parts in-circuit. This is how I do it...