Annoyed by the unnecessary bulk of existing solutions, [cperiod] has come up with an ESP8266 temperature and humidity sensor that can plug directly into a standard USB port.

First the obvious-in-retrospect fail. [Richard] built a board with a temperature sensor and an ESP8266 module to report the temperature to the Interwebs.

If you want to get started with motion sensors and the like, ESPHome makes it incredibly easy to build your own sensors.