At 01:19 PM 11/11/97 -0800, you wrote:
>Does anyone want to volunteer some programming expertise and development
time?
> Anyone? Anyone?
>
> - Rick "Bueller?" Dickinson

Rick,

I love your idea and I was actually working on a simpler sonar-ranging
device before this idea got introduced as a thread here. I am mainly
developing the best actual RX and TX circuits as well as what is the best
format for the sonar pings ( # of pulses, null period to avoid transmitted
vibration detection, etc. ). I have only been working on it for a few days,
so far I have a very simple circuit which seems to have very little problem
actually receiving the signal. I am mainly ironing out the timing issues
and digital detection method (I am currently using a PLL, but this is
having trouble locking reliably on only 40 cycles, which I thought might
happen, so I am moving from a PLL to a comparator clipping/direct PIC
detection method). I would like to help, not sure how much time I can
contribute, but I will contribute any major advances that I have. I have
two questions, what type of maximum range do you want this to handle and
what will be the accoustics of the areas where you envision it being used?
This is tough to implement >10meters range when indoors because stray
reflections are detected.

Sean

Sean Breheny,KA3YXM
Electrical Engineering Student