ANAVI Thermometer is an open source hardware, Wi-Fi development board for measuring temperature that's powered by an ESP8266 processor.
It comes with a built-in DHT22/AM2302 temperature and humidity sensor and has slots for a mini OLED display, waterproof DS18B20 temperature sensor, and empty slots for up to three additional I2C sensor modules.
All these features make ANAVI Thermometer appropriate for developers, makers, students, and open source enthusiasts interested in home automation.