■ FIGURE 2. The Bluetooth SIG plan for what is to come
with the new low power version 4.0 standard.
Courtesy Bluetooth SIG.
recent scare that cell phones give you brain cancer. There is
no absolute proof yet, but many believe that holding a high
power microwave device by your head for a while everyday
can cause damage. In the meantime, if you are paranoid,
just use a Bluetooth headset. No problem.
One of the best applications for Bluetooth is cable
replacement. A good example is replacing serial data
connection cables in systems that use the popular RS-232 or
RS-485 protocols. These low speed interfaces are still widely
deployed in industrial and some commercial applications.
Connections to older printers or industrial automated
machines like programmable logic controllers are examples.
You can buy Bluetooth radios that just plug right into the
standard connectors and link up automatically. Products
from Quatech, Inc., are good examples. Figure 1A shows
their CS0400-479 serial adapter. It plugs right into a
standard RS-232 nine-pin DB9 connector and gets its power
from the system or an external supply if needed. It can
implement any of the standard data speeds from 1,200 bps