Captures temperature and humidity and publishes to MQTT.
Current hardware is a Huzzah ESP8266 from Adafruit and an Si7021 breakout also from Adafruit.
Another alternative for temperature/humidity sensors is Sparkfun's HTU21D (use esp8266_HTU21D_MQTT_TH1.ino).
Solid model for 3d printing an enclosure to follow.