The disclosure herein describes enables new sensors to be added and maintained in an Internet of Things system without upgrading firmware for the end device. A sensor abstraction layer (SAL) manages the end sensors, and a sensor definition layer (SDL) in the cloud interfaces with the SAL. Sensor definition data of a sensor connected to the end device is identified in a sensor definition data store of the SDL including sensor configuration data. The sensor configuration data is sent to the SAL, wherein the SAL is configured to collect sensor data from the sensor via a sensor interface. Sensor data is received from the SAL via an established network connection and converted into converted sensor data based on a data conversion model of the sensor definition data. The converted sensor data is then provided to an application, connected to a sensor management device, for consumption.