Nice project + write-up from Jamie Bennett up on LinuxUK.
There are a wide range of solutions on the market today to help the avid gardener with their plants, some are low tech battery-less meters designed to give you a simple view of how your plant is doing, others are much more high-tech (and expensive). Two of the most important variables to monitor in a greenhouse are temperature and humidity, too hot and plants start to scorch and wilt, too cold and they can be damaged, and humidity is important for a whole host of plants you may find in a greenhouse.
At home I have a modest greenhouse, at 3 metres by 1.8 meters it has just enough room to start off delicate plants early and keep the family supplied throughout the season with chillies, tomatoes, cucumbers, strawberries, herbs, and even lemons. Although I can just barely make out the digital … // Read more: original article.