IoT Building Block 1: Collect - Edge Devices (Sensors & Actuators)
This is the front-most device of any IoT system. It primarily works as either a sensing device to collect physical environment information, or as an actuator to control the outside world with an output. In some cases, edge devices perform a dual role, acting as both a sensing and actuating device to collect and control the physical environment.
The edge node must be connected to the outside network, either through a wired or wireless sensor node (WSN). Data integrity remains key in this block of the signal chain as many IoT systems utilize a large number of sensors to collect data and make intelligent decisions.
An edge node device provides the intelligence to sense, measure, interpret, and connect an internet gateway to the cloud. The data can be pre-processed with some form of analytics before it is transmitted for deeper data mining intelligence.
Processing nodes provides local intelligence to the entire network of sensors and applications. Typically, a processing node involves one or more microcontroller, microprocessor, hybrid circuit, etc. and may be relatively larger in size as compared to end-nodes. Processing nodes are not readily available devices; they are custom made by designers to meet the specific needs of their application.
Bigger IoT applications require a large array of edge devices in order to form a network of edge devices. In such cases, each edge device (node) needs to have a unique identifier in order to recognise and communicate with them effectively.
Typical examples of Edge Devices (Nodes):
Sensors: Temperature, Humidity, Pressure, Gas, Light, Sound, RFID, NFC, Ultrasonics, Flow Meter, Fluid, Cameras, etc
Actuators: Switch, Relays, PLCs, Motors, Light, Sound etc