This code contais code for a temperature and humidity sensor based on the esp8266 microprocessor.
In this setup I used the NodeMCU esp8266 board that facilitates the popular DHT11 sensor for measurement. The board is wifi enabled so there is no further extension shield required to access the internet.
The software uses the esp-open-rtos real time operating system. You will need to use the esp-open-sdk to build and upload the software onto the chip.