KhaledOsmani
Full Member level 6
Hello
I hope to built a circuit based on PIC18F4520 that executes the following:
Whenever connected a telephone twisted pair line of 0.4mm thickness (only), an LCD tells its distance after ohm to length conversion.
The idea principle is based on Ohm's law.
I've seen similar projects, using a voltage divider, whereas the line can be considered as pull down to ground resistance, then Vcc is sensed via PORTA, and after math conversion one can know the value of the resistance (in this case, a copper line), therefore can know its length. What I don't like in this project is one must connect the two terminals of the line, to be able to know its resistance hence length. The problem is that there are cases where one cannot reach the other terminal of the line (maybe it is underground buried somewhere).
What I want to make is to design a circuit, where one can connect twisted pair two terminals to PIC, then length is shown on LCD. It is similar to the functioning of 3M Dynatel 965 in its open circuit function (tells where the line is open).
Any thoughts please?
Thanks in advance
I hope to built a circuit based on PIC18F4520 that executes the following:
Whenever connected a telephone twisted pair line of 0.4mm thickness (only), an LCD tells its distance after ohm to length conversion.
The idea principle is based on Ohm's law.
I've seen similar projects, using a voltage divider, whereas the line can be considered as pull down to ground resistance, then Vcc is sensed via PORTA, and after math conversion one can know the value of the resistance (in this case, a copper line), therefore can know its length. What I don't like in this project is one must connect the two terminals of the line, to be able to know its resistance hence length. The problem is that there are cases where one cannot reach the other terminal of the line (maybe it is underground buried somewhere).
What I want to make is to design a circuit, where one can connect twisted pair two terminals to PIC, then length is shown on LCD. It is similar to the functioning of 3M Dynatel 965 in its open circuit function (tells where the line is open).
Any thoughts please?
Thanks in advance