How to interface RCA cable using PIC16F877?

[bing2005]

Interface with RCA cable

Can anyone tell me about the proper method to interface RCA cable by using a PIC16f877?
This RCA cable is attached to a depth transducer. I want to interface it to receive the signal and display the value on LCD.
Thank you so much!!!

 

[IanP]

Re: Interface with RCA cable

Quite often depth transducers (pressure transucers) are of 4-20mA type.
They will accept voltages from 10-30Vd.

If that's the case you will have to identify the sensors positive pole and connect a dc supply there and connect termination resistor of, say, 250Ω between sensors output and 0V. For the rannge of 4-20mA the voltage accross this resistor will be 1.0V to 5.0V and this voltage can be fed directly to a PIC with AD converter ..

 

[bing2005]

Re: Interface with RCA cable

Thanks IanP, for your quick response.
The RCA cable only consists of 2 wires; 1 for ground and another one for receiving the signal, am i right?
The transducer i used is from Navman company. It is a single frequency transom mount depth transducer.
So, i just need to connect a resistor in between RCA output and its ground then supply it with voltage.
Do i need to construct any transceiver or echo sounder to this device?
Thanks a lot.
Its specification only indicate that Max. power consumption: 60mA
and Current Drain: 150mA
Its supply voltage is 9.5V to 16.5V

 

[IanP]

Re: Interface with RCA cable

So, it is not "pressure" transducer but ultrasounder.
If you have just transducer that is a bad news as the circuit required to make them working is not simple.
Basically, you need to send a signal and measure time till the same transducer receives the echo .. sounds simple but in reality it is not.
Better contact Navman ..

 

[bing2005]

Re: Interface with RCA cable

Thats really a bad news because i try to contact with navman before.
But, they refuse to answer the technical question.
Anyway, thanks for your information. ^v^