The best communication protocol

[bgsteiner]

For one of my projects in development I need to be able to send data over about 100ft of cat5 cable. I am wondering what protocol I should look into using. Wireless is not an option as it is too unreliable with the space I am working in. My plan is to create a modular HID keyboard so that an adapter will translate signals from a node into key presses so the node needs to be able to send key codes.

All help is greatly appreciated!

[ovnr]

Assuming you use a microcontroller: RS485 signalling. Just use your MCU's UART (think RS-232), then shove it into a RS-485 driver. Add appropriate termination on the end, and off you go.

Of course, pretty much anything goes because it sounds like a fairly low-speed link. It'd probably be fine to just shove TTL signals down the wire, but obviously less robust.

[Richard Crowley]

The OSI model of computer networking is like a 7-layer burrito from Taco Bell.
But I think you probably don't need the top 5 layers, and you are asking about layer 2...

7. Application
6. Presentation
5. Session
4. Transport
3. Network
2. Data Link -  For an application as you describe, I would use bog-simple asynchronous serial.
   I would use RS-422 balanced, differential signaling to take advantage of the super-balanced Cat cable.
   If you need something more sophisticated, consider RS-485
1. Physical  -  You have established that you want to use Cat5 cables, presumably with common RJ-45 connectors.


Ref:
http://en.wikipedia.org/wiki/OSI_model
http://en.wikipedia.org/wiki/Data_link_layer
http://en.wikipedia.org/wiki/Serial_communication
http://en.wikipedia.org/wiki/RS-422
http://en.wikipedia.org/wiki/RS-485

[Smokey]

...
The OSI model of computer networking is like a 7-layer burrito from Taco Bell.
...
/quote]

I love it.  I'm going to have to come up with Taco Bell metaphors for all my electrics explaining needs...

Coax cable is like a taquito from Taco Bell....
Anti-static bags are like the paper wrapped around your taco at Taco Bell...
Leakage is like what happens to your body after you each some bad meat at Taco Bell.....