The blog post details the integration of a Tessel Climate Sensor with the PubNub real-time library to transmit temperature and humidity data over WiFi using a Tessel board, a JavaScript-powered microcontroller. It explains the setup process, including installing Node.js, Tessel, and PubNub libraries, connecting to WiFi, and ensuring compatibility with specific climate modules like si-7020 and si-7005. The post provides guidance on writing JavaScript to control the Tessel, initiating the PubNub service with unique pub/sub keys, and setting up an interval to read and publish climate data every twenty seconds, while handling potential errors. This setup allows users to monitor and regulate environmental factors effectively, and the upcoming Part Two promises to showcase the visualization of the collected data on a live-updating chart.