[Orcnet] Product wanted - (or idea?) - turn signal beeper

[Keith Lofstrom]

While visiting back east, I noticed that some of the older relatives
leave their turn signals on.  They can't hear the little click of
the relay under the dashboard.  They may leave the signals on for
miles after a turn or changing lanes.  To warn the drivers, I've
seen some schematics for lashups of diodes and 555s and buzzers
on the Internet, but most of them seem pretty user hostile. 

These are typically powered by a diode connection to the 12V power
to each of the indicator lights.  They either come on blaring as
soon as the signals light (OK for open motorcycles, for automobile
cabins, not so much) or else have 10 to 20 seconds of time delay,
which would be startling and perhaps lethally distracting.

Thinking about it, a better alternative would be a single chip
CPU (PIC?) with a builtin ADC/DAC, connected to a transducer
usable as both a microphone and a speaker. This hypothetical
device produces a tailored sound depending on ambient sound
level and the delay from the time the indicator first lights. 
It may only get high power when the lights flash,  with a
capacitor helping it run a timer and some memory between
flashes.  It would be nice if there was some way for the user
to program the behavior.  Perhaps the device could also
indirectly sense open or shorted indicator bulbs.  The fewer
connections the better.

If there is something like that already out there, I would 
appreciate pointers.  If not, perhaps somebody might want to
make a product like that.  Besides the design, much effort would
be involved writing aftermarket installation instructions for a
zillion different kinds of cars.  The product might help a few
old folks avoid embarassment and focus a little more attention
on the road, and many would be purchased by frustrated friends
and relatives ...

Keith

-- 
Keith Lofstrom          keithl at keithl.com         Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs