power line communication

hai....iam trying to send adress of sensors(like smoke and fire) thru powerline,for that iam studying microchip AN236,but some problems are there.
1)the code is written in assembly.
2)no body in fourms prooved that the software is working after build.
3)and the CFL,SMPS,MOBILE CHARGERS may block the 120 khz carrier...
4)in the software part the time of burst is applied in60 hz mains,not in 50 hz...

shall i start with all these problems?

is there any idea in ccs c? for x10?(without using additional supporting chip!)

pls advice me before i start this proj...:!:

Communicating through power lines is one of those things that sounds stranger than fiction.

I've seen commercial products that control appliances, etc. They work by sending AC or DC pulses backwards into a power outlet, where they go to another part of the house. A sensor (plugged into a different outlet), picks up the signals and turns an appliance on and off.

I think I heard it doesn't work between separated houses. Or transformers. Or it may not always work if the signal must go through circuit breaker coils. Etc.

The transducer inside the devices must not be overcome by the 120V AC. (You probably have 240VAC.)

And as you point out the communicating signal must get through despite interference from fluorescent (or CF) bulbs, etc.

I imagine the signal must be strong enough that it would show up on an oscilloscope. Have you examined what your house AC looks like on an oscilloscope? Whether it has noise, spikes, etc.?

Caution if you do this. The scope input should not be connected directly to power lines.

You'll find out a great deal simply by trying out one of the commercial products and seeing what the signals look like on the power lines.

thanks for your reply sir,,i tested with an oscilloscope(used isolation transformer)and checked the wave,,,not so good.impulses are there a lot in sinewave...may be the electrical-rf-noices...but a good news also there, i plugged an old cordless fm intercom to next house(nearly 1/2 km appart frm my house,and pushed the call switch,same time i heared the ring tone in the slave end,,i checked with scope and a clean fm carrier around 367khz recived on the pll input of reciver...this way i sure that plc is possible...these intercoms are old technology..but using zerocrosse with a pic micro i strongly belive this will work...here iam attaching a document of plc...unfortunately source code is not compleated...can you go thru this and guide me to construct one?

Sorry, I have no experience with the X10 system, nor with microcontrollers.

The article about X10 was interesting. It works by transmitting a couple bits at a time just after AC power crosses zero.

It doesn't say what voltage comes from the sender. Nor does it say how much current it must provide.

Too low a voltage will be lost amid noise on the lines. Furthermore you can expect the voltage to drop over the distance to a remote receiver. Your device must send out a high enough voltage to take that into account.

The signal may be drawn down by appliances at unknown locations in the power lines. Therefore your sender must have low enough output impedance, so it can provide sufficient current.

It may or may not make a difference which wire you send through. Are you using the intercoms which you plug into power outlets in different rooms, and you can talk through the power lines? Because I have used them and it doesn't matter which way I plug them in.

Even though either way is a round trip for the electrons, you should experiment to find out which wire carries your signal best. Also at the receiver, experiment to find out which wire brings the best signal.