Use an event driven architecture in your IoT devices

Using an event-driven architecture in IoT device firmware reduces processing and communication overhead, and helps reduce energy consumption.  There are a number of mechanisms that can be used in IoT devices to realize an event-driven architecture.

Design device software to minimize the amount of energy IoT devices consume while checking for events or data. By using interrupts instead of continuous polling, the CPU can sleep until an event occurs, reducing the time the device spends actively checking for data or events.

Another mechanism is Pub/Sub topics (such as those used by the MQTT protocol). Devices that subscribe to specific topics receive notifications when new messages are available, allowing for appropriate processing to be triggered. 

Asynchronous callbacks are another technique used to realize an event driven architecture.  In this model, the device firmware registers callback functions to be executed when specific events occur. This enables efficient processing of events without the need for polling or continuous querying.

Real time operating systems such as FreeRTOS are built for event driven firmware by employing the use of priority interrupts, pointers to callback functions, and multi-threading.