Serial rf communication

[dhouston]

I am experimenting with the Linx rf modules, the TWS and RWS 418Mhz.

There are some excellent application notes on the Linx website. You should add them to your reading list.

• http://www.linxtechnologies.com/Supp...ication-Notes/

Bruce Reynolds also has some useful wireless tutorials & projects on his website.

• http://www.rentron.com/remote.htm

For small payloads, I prefer using the protocol that NEC introduced many years ago with their IR remote controls. It and slight variations have been used by many others over the years both with IR and RF. It's a bit easier to understand than manchester and other encoding schemes, is simple to implement, has built-in error detection and, because it sends an equal number of ones and zeroes, has good DC-balance over the length of the (relatively short) messages. It also illustrates the use of a different type of preamble to set the AGC/ATC in the receiver and alert the receiver that a message follows. There's an implementation I've used extensively with TWS/RWS modules in the Code Examples forum. See http://www.picbasic.co.uk/forum/showthread.php?t=6261