Hi, I am working on my graduate thesis and i really need help.

I am to build an electricity meter which should be able to communicate through a LAN (the device should be able to connect to a hub and then send data to a pc.). My problem is if I should build an "ethernet controller" to be able to send data to the hub/network/pc. My device will have a Z8 microcontroller for processing and initially I thought it was as straight forward as in RS232 communication. Any help from you guys is greatly appreciated. Thanks!

 

It might be easier to use an ethernet module or serial to ethernet converter. There are many of them on the market, they are relatively easy to connect to microcontroller or processor. Have a look on this page http://www.beyondlogic.org/etherip/ip.htm.

 

A couple of standards might help RS422 and RS485. RS422 is point to point, RS485 can have multiple devices. These two standards run farther than RS232. RS232 can run 50 feet. RS422 or RS485 can run 4000ft.

http://en.wikipedia.org/wiki/RS-422
http://en.wikipedia.org/wiki/RS-485
http://www.rs485.com/rs485spec.html

Converters.
http://www.bb-elec.com/RS232.asp

Here is a schematic for one end of a circuit.
http://www.airborn.com.au/layout/232to485.html

You may not need one on your device if you're using TTL, you'd just need the 75176 chip and that part of the circuit.