Internet of Things

7The IoT in Practice

7.1 Hardware for the IoT

The IoT is expected be a worldwide network comprising, by 2020, billions of devices. This gigantic number of devices, pervasively deployed, will be characterized by their heterogeneity in terms of software and, in particular, hardware.

In order to provide a general definition for hardware platforms, Figure 7.1 shows an high‐level view of the main hardware components in a smart object. The illustrated modules are:

• Communication module: This gives the smart object its communication capabilities. It is typically either a radio transceiver with an antenna or a wired connection.
• Microcontroller: This gives the smart object its behavior. It is a small microprocessor that runs the software of the smart object.
• Sensors or actuators: These give the smart object a way to sense and interact with the physical world.
• Power source: This is needed because the smart object contains electrical circuits. The most common power source is a battery, but there are other examples as well, such as piezoelectric power sources, that provide power when a physical force is applied, or small solar cells that provide power when light shines on them.

Figure 7.1 Smart object hardware, with (a) radio network interface and (b) wired communication interface.

Microcontrollers have two types of memory: Read‐only memory (ROM) and random access memory (RAM). ROM is used ...