> Ok but that's with money! Some free ideas ? > I saw something about two 16f877 connected on radio link > It's something visible on net ? > Vasile :-) , there are no such thing as free lunch, one way or the other one must build something, that manages to communicate by means of RF. using the chips above would save you alot of hassle ( not to mention avoiding illegal RF band usage ). And, trust me, these are VERY cheap concidering bang for the buck. ( if I recall correctly something around $10 each ). About three wires to connect, Din, Dout, Txenable. And, just checked it, they are at 20kbps, FSK modulated, standby 8uA, tx 8mA, two channels etc. Could it be any easier ? Tony KŸbek, Flintab AB ΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣ E-mail: tony.kubek@flintab.com ΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣΣ