PIC based SONAR

[PICtron]

Hi,

could someone help with a schematic for a SONAR?

Requirements and findings so far:

I have got a Transducer tuned at 200kHz.
(Receiver and transmitter consisting of a single piezo, so only two wires)

The available Supply Voltage will be 12 VDC.

The general idea is to send out a "burst" of about 10 pulses at 200kHz.
Then short the Transducer for a short period if time to stop it from resonating.
Then measure the time for the echo to come back.

So far it sounds simple,
but to increase the amplitude of the burst
I would like to reverse the polarity of the two wires of the transducer
rather than having one wire tied statically to GND and sending HIGH's and LOWs to the second wire.

The Transducer will draw quite some power when active, so I will certainly have to use MOSFETs.

Any Input will be appreciated.

Thanks

[Dwayne]

Hello Pictron,

PICtron>>The general idea is to send out a "burst" of about 10 pulses at 200kHz.
Then short the Transducer for a short period if time to stop it from resonating.
Then measure the time for the echo to come back.

So far it sounds simple,
but to increase the amplitude of the burst
I would like to reverse the polarity of the two wires of the transducer
rather than having one wire tied statically to GND and sending HIGH's and LOWs to the second wire.<<

Remember that sound travels MUCH faster in water, than in does in air.

Depending on your distance, 10 pulses is probalby way too many. maybe one pulse is the answer with a timeout of X Mils<g>.

Dwayne