The hardware is consists of an Arduino microcontroller (here an Arduino Uno R3) and a pre-wired soil moisture sensor module. The soil moisture sensor module , built around the LM393 comparator, gives ...

temperature and humidity sensors, an RTC, and a Bluetooth module for uploading data to a phone. [Rui] even manages to work in an homage to the grand-daddy of all arcade games with a Pong splash ...

The eBay hacker favorite, the so-called DHT22 module, doesn’t fare all that ... microscope to figure out what’s going on. The other sensors were fine, with the HTU21D and SHT71 being standouts ...