If you're in the US, Adafruit sells them for $10 and they can ship fast. I used it myself to have the ESP8266 report temperature and humidity to my home automa

If you're in the US, Adafruit sells them for $10 and they can ship fast. I used it myself to have the ESP8266 report temperature and humidity to my home automation: https://home-assistant.io/blog/2015/10/11/measure-temperature-with-esp8266-and-report-to-mqtt/ https://home-assistant.io/blog/2015/10/11/measure-temperatur...