Agree USB is good. But it doesnt go for the commercially available BT
products.

Bjarke

"Meindert Sprang" wrote in message
ll.nl...
"Bjarke M. Christensen" bjarkeNG@grevestrand_punktum_danmark wrote in
message k...
That my ear-device for my telephone contantly get confused and that my
f...... bluetooth keybord and mouse has to be re-installed every time I
replace the battery. I wish I'd opted for the IR version or cable ....

Those are typical examples of bad design to save money, resulting in bad
reputation of the technology. The same has happened with USB. Both
technologies allow for beautiful solutions when done right from the start.

Of course I am biased, since I have designed bluetooth and USB enabled
multiplexers that do work properly :-)

I have had customers buy a multiplexer with a serial interface (resulting
in
the infamous "crazy mouse" problem in Windows) because they were reluctant
to buy one with a USB interface. And it is precisely the one with USB
interface that does NOT have this crazy mouse problem and always works,
like
PnP/USB was supposed to work.

The same with bluetooth: by using better modules than cheap consumer
stuff,
pairing info is stored permanently and every time the system is brought
up,
the communication is there as if a serial cable was attached. But the
cheap
consumer stuff is stripped down to the bare necessities, and to save
another
50c on cost, the non-volatile memory chip needed to store this sort of
info
is omitted.

A similar problem exists with USB devices, by omitting a tiny chip with a
unique serial number, windows can only recognize a cheap usb-serial
converter by the USB port is is plugged in, resulting in a different com
port number when you plug it in a different USB port. By adding this
little
chip, such a converter would have the same com port number, no matter
which
USB port on your PC you plug it into.

Meindert