send data over the 230 phase line :)

Using Arduino General Electronics
#1

Nowadays you have internet comming out the wallplug, so I thought there must be a way to let an arduino talk to an other arduino over the 230V phase line.

As I only have 1 data line available it must be asynchronous. That is why I am thinking to use the Uart of arduino.

I want to connect the Tx pin of one arduino via a high pass filter directly to the fase. If I chose my components that I have cut-off frequency of about 100kHz the 50Hz tranfer is almost nothing, less than 1/1000. While the dataline has less than 6dB transfer loss. On the other side I want to connect the phase via the same high-pass filter to the Rx of an other arduino.

What I am unsure about is how to couple the arduino grounds to the null. I was thinking to use the same capacitors. Is that recommendable or what other components should I place in the black boxes?

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#2

I don't think it's that simple.
PLC

AC data communication

#3

Google "power line modem" for a reliable way to send data over the AC line.

#4

And be sure your last will and testament is up to date just in case that 230v mains doesn't play nice with you.

#5

I already thought it would be a bit trickier than that :wink: I need to use the 50Hz as carrier wave and modulate it with the 115kHz information using amplitude shift keying.

From what I read on the internet I need to make use of a coupling transformer to get my information on the AC line. I also need to read the ASK part again in my telecom book and talk with my teacher ( ← knows alot about signal modulation). With AM the higher frequency is typically the carrier wave where the lower frequenty carries the information.

I got the basics real quick from this site: Loading...

I hope I can do it without the need of a special IC.

#6

You can't modulate a 50Hz carrier with 115kHz! You are injecting a carrier at 115Hz, the 50Hz is
completely out of band and irrelevant to the communications other than it requires (safely) filtering out
before demodulating due to the large voltages. Even a single pole filter will perform well when the out
of band signal is 1/2000th of the frequency of your signal carrier.

#7

You're assuming your power signal does not contain noise > 50Hz ...
Which I think is a pretty naive assumption. I think noise and high frequency signals generated by devices on your power network will probably be the greatest challenge ...

#8