This is the third video in the series "IOT with Raspberry Pi" and that's using JAVA. The series comprises of Sensor interfacing using pi4J, REST API usage with JAVA, MQTT usage with JAVA and finally adding all to the same project and running over Raspberry Pi. last two videos shows how to interface DS18B20 1 wire temperature sensor with Raspberry Pi and send data to Thingspeak by using REST API with JAVA. If you have not checked those you can do that with the links down below. This video is the 3rd in the series and is about how to publish or send sensor data using MQTT API to cloud. And in this, we are using ThingSpeak as cloud service to publish data.Publishing Data using MQTT is done using Eclipse PAHO lightweight library. MQTT is a simple lightweight publish/subscribe protocol that can be used over TCP instead of going for HTTP as MQTT is power friendly and bandwidth friendly as compared to HTTP. So it fits perfect for IOT applications. If you are interested in more about it, you can check some docs linked below.