RS232 and RF tranmission

[KALKAN]

I want to make remote control device. I use SEATALK sistem. when reciver and transmitter connected with cable are working. but I use RF module no working.
what can I do this about?

[Ttelmah]

Generally, the problem is that when using most radio modules of this type, the data must average to having a symmetrical number of 1's and 0's in the packet. Also normally, there has to be a 'prequel' to the required data, to allow the AGC in the receiver to stabilise. Hence data must be 'repackaged' from a format like SeaTalk, before trying to send over a radio link. There have been a huge number of posts in the past about the various ways of achieving this type of transmission (the 'classic' is 'Manchester encoding', which ensures the balanced streams, but for low data rates, may be uneccessary, with simply repeating each byte after a logical inversion being a possible alternative. You need to look at the data sheets for your radio devices, and find out what restrictions there are on the data to be sent. A simple prequel may be all that is needed. Otherwise do a search on the forum for 'Manchester encoding', to find some of the threads about this.

Best Wishes

[newguy]

http://www.ccsinfo.com/forum/viewtopic.php?t=23953

Try the above implementation. It works.

[KALKAN]

THANKS,
I WAS WORKING WHITH 4800 BAUD. I CHANGED FROM 4800 TO 2400 IT WORKED.