Specifications

93Environmental Automation
of events and the corresponding
lighting and A/V equipment needs
are preprogrammed so that, as an
event progresses, the operator simply
triggers the next settings as needed.
Similar systems are available for the HAS
that can control everything from lights,
temperature, A/V components, TV/movie
playing, and even powered drapes. With
occupancy sensing and response, lights
can be programmed to automatically
come on when you approach and turn
o, with some delay, after you leave. With
phone-call sensing, TV and A/V systems
can be muted when a call comes in.
Sensors needed include ambient light
and proximity sensing (MAX44000) and
remote wireless transceivers (see the
Wireless Systems section in this chapter).
They may derive power from energy
harvesting (MAX17710) and charge
batteries for high pulse loads as needed
when they transmit, while eliminating
the need to replace batteries. This means
no wires and no battery replacement.
Alternatively, if the equipment is
wired to the Ethernet and if it draws
low power, power over Ethernet (PoE)
provides a convenient installation
alternative, especially if Ethernet
cabling is already installed (go to: www.
maxim-ic.com/power-over-Ethernet).
If not installed, communication can
also be accomplished with powerline
communications interfaces (go to:
www.maxim-ic.com/powerline).