This project doesn't call for a new hardware requirement, as we will still use the same hardware that we have used in the previous chapters, where we measured data using the photocell and temperature sensor. We will just add a soil temperature and humidity sensor for this chapter.
The soil sensor that we will use is an SHT-10-based sensor encased in a metallic mesh. The casing keeps water from seeping into the insides where the sensor actually is, but allows air to pass through. This way, the sensor can measure the humidity and is kept dry.
This sensor contains a temperature/humidity sensor module from Sensirion, and the temperature readings have 0.5 percent precision, while the humidity readings have 4.5 percent precision.
As for the relay, we will still use the...