themselves into the fabric of everyday life until they are indistinguishable from it. —— Mark Weiser, Xerox Parc, 1991 The Computer for the Twenty-First Century
now beginning. First were mainframes, each shared by lots of people. Now we are in the personal computing era, person and machine staring uneasily at each other across the desktop. Next comes ubiquitous computing, or the age of calm technology, when technology recedes into the background of our lives.
do something else. • The best computer is a quiet, invisible servant. • The more you can do by intuition the smarter you are; the computer should extend your unconscious. • Technology should create calm.
of Things, haptic computing, and "things that think” • Research topics: distributed computing, mobile computing, location computing, mobile networking, context-aware computing, sensor networks, human-computer interaction, and artificial intelligence.
and other items—embedded with electronics, software, sensors, actuators, and network connectivity that enable these objects to collect and exchange data.
in the deployment: • Don’t have routable connectivity to the Internet, for example, Bluetooth devices. • Don’t have processing capability needed for transport-layer security (TLS) and as such can't communicate with Google APIs. • Don't have the electrical power to perform required network transmission.
devices are capable of communicating without one, in order to: • Condensing data • Cache data • Manage Timestamps • IPV6 to IPV4 translation • Ingesting and uploading other flat-file-based data • Firmware updates
a publish/subscribe, extremely simple and lightweight messaging protocol, designed for constrained devices and low-bandwidth, high-latency or unreliable networks.
transfer protocol for use with constrained nodes and constrained networks in the Internet of Things. • The protocol is designed for machine-to-machine (M2M) applications such as smart energy and building automation. CoAP
protocol for message-oriented middleware based on XML (Extensible Markup Language). • It enables the near-real-time exchange of structured yet extensible data between any two or more network entities. Originally named Jabber.
are common • Typically, the forward voltage of an LED is about 1.8–3.3 volts; it varies by the color of the LED. A RED LED typically drops 1.8 volts, but voltage drop normally rises as the light frequency increases, so a BLUE LED may drop around 3.3 volts. • To connect a LED to Arduino or Raspberry Pi: 5V - 2V / 0.02A = 150 ohm