You know, in my opinion, there are certain things that you should leave to
those who
have done it before.  I'd buy a ultrasonic system off the shelf. GEM maybe?
I've used a few NEMA4 ultrasonic devices, 4-20mA outputs, and they are only
a few hundred.  Its easier to use it than package something and also not
have to worry about sparks and such...

just my 0.02 worth...



-----Original Message-----
From: Richard Gibson [mailto:uncle_percy@HOTMAIL.COM]
Sent: Monday, January 18, 1999 1:30 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: Ultrasonic Level Measurement


Hi

I am building an ultrasonic level measurement system for an oil tank.
The system is to take readings of the oil level periodically and
transmit them (via an RF link) to a remote location to be displayed. I
was thinking about using PICs to control both parts of the system.

Part 1. the level measurement unit , this would consist of an ultrasonic
transceiver , control system an a radio transmitter.
This part of the system is to be battery powered. Could a PIC be used to
drive the ultrasonic transmitter ? (generate pulses)

Part 2. The remote receiver + digital display.
A PIC would be required here to decode the received signal and drive the
display.

I have no previous experience of using PICs , and I would appreciate any
suggestions  or ideas on what PICs would be most suitable and how they
might be used in this type of project.

Also has anyone any ideas on how to compensate for the variation in the
speed of sound due to atmospheric conditions.

Richard.



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