Long wire bring voltage down

Hi guys I need a long wire to connect my arduino to some speakers and some sensors like photocell the wire length would be about 20,30 meters so the voltage will defenantly go so down so it won't work and I need long wires for so many things that I want to control in this project so should I amplify the voltage if yes how?? If no what else can I do. Tnx

V = IR

In otherwords you'll need to know the current and the resistance of the wire to start with...

And say more about what you are controlling, "the thing I want to control" conveys no information
to us.

I want to control the wire length would be about 20,30 meters so the voltage will defenantly go so down so it won't work

[u]This chart[/u] shows that 1000 meters of 22AWG wire has a resistance of ~50 Ohms.

That could be an issue if you are transmitting power, but for DC signals it's not an issue. With audio or high-frequency pulses you could potentially get noise or "impedance" issues with long runs, but DC voltages (at low current) should get from one end to the other with no measurable voltage drop.

OK guys thanks for the reply lets say I wanna connect the wires to some relay module and some sensors like photocell.Then 30 meters of wire will it effect so bad?? Or stop things from working. I was thinking about using an electric piece and use a little programming from knowing the voltage of the end of the wire and some math to fix the voltage does it worth?? And what electronic piece will do Sth like that?

The most likely problem is that the long wire will pick up electrical noise.

Use shielded cable for such connections, and make sure that the shield is connected to the Arduino ground.

Or run two Arduino's with wireless Xbees. One with the data collection code sensors etc and the other with the data processing code. Depends on how and where the sensors etc are ie - can they get power from a local source

Tnx guys for your info.i got some motivations so it will make some noises nth really big.Good thanks again.

Stevemoretz:
OK guys thanks for the reply lets say I wanna connect the wires to some relay module and some sensors like photocell.Then 30 meters of wire will it effect so bad?? Or stop things from working. I was thinking about using an electric piece and use a little programming from knowing the voltage of the end of the wire and some math to fix the voltage does it worth?? And what electronic piece will do Sth like that?

V = IR. We've told you how to calculate the voltage drop from the wire resistance and the current passing
through it - you need to find out the current and the resistance and do the calculation. It could be 0.05V or 10V
depending on the numbers, so you have to work it out. And remember there are 2 wires the current has to flow
down and each loses voltage.

Without the numbers we are just guessing blind.

Let's say the voltage is 1 and the resistance is 50 ohms so now what can I do??
I know Vb=Va-IR and now Vb is 1 volt for example so then what?

No lets not say the voltage is anything, we are trying to calculate the voltage.

Find out the resistance of your wire (this is easy, there are charts for this this all over the web, and
you can calculate it directly for copper if you know the cross-section).

Find out the maximum current of your load.

Multiply them together and double since there are two wires. That's the total drop-out voltage from the wiring

Sorry bro I just asked this question because I will do it someday its not my current project and I just want to know what to do in this situation?could you bring me an example please?with real numbers? I'd really appreciate it.

Well why not use your real numbers - what wire and current are we talking about?

That's the point bro I use an emulator for using arduino I haven't bought a real arduino yet I'll get it soon that's why I'm asking you to use your real numbers please if I could I wouldn't bother you bro.