[nearengine]

I haven't yet, unfortunately the project has been on the backburner the last year or two since I've been so busy with other things. So far I've basically hooked up a relay board with an I2C GPIO extender, and use the Pi to toggle relays for lights and pumps. I also have an Arduino hooked up via serial that acts as an environment sensor, logging TDS, pH, light status (with a basic photoresistor, although this could be expanded to a fancy color temp sensor), and temp+humidity. It also monitors water level via a float switch. When the float switch is triggered, it adds more water. This naturally brings the TDS down, which triggers relays for peristaltic pumps to add a given ratio of nutrients.

The goal is to have a RESTful API service running on the Pi so that I could deploy one Pi+environment sensor setup per reservoir with a basic js app to monitor variables and set the timers and nutrient schedule, and if necessary aggregate that data into a centralized management frontend for multiple reservoirs.