How to encode a RF signal ?

Lorenzo · Joined: 23 Apr 2004 Posts: 14 Location: Pescara (Italy)

I've to encode a RF signal with a 16F873A.
The other side decoder is a Samhop SM5028 or a Holtek HT12E.
Has anyone the right routines ?
Thank you

Gabriel Caffese · Joined: 09 Oct 2003 Posts: 39 Location: LA PLATA, ARGENTINA

Lorenzo,

Take care, HT12E is an encoder too. The decoder one is HT12D.
Is the receiver part already done, or you have to build it ?

I sell remote controls for being used in low security cases, and use Holtek´s. When security must be high, the same boards (Tx and Rx) support and 16F627, and allow transmiting at 2400bps with a very high encoding (32bits).

So, if none of the parts are done yet, and need high security, or need a micro at any of both sides, why don´t you use any RS232´ed micro, and attach MPSH10, some L and C, and get a really cheap, small and secure
RF link ?

Gabriel.-

Lorenzo · Joined: 23 Apr 2004 Posts: 14 Location: Pescara (Italy)

HT12D, ok.
My receiver is made of an AM receiver with its output directly connected to micro.

Guest · Guest

Lorenzo -

I assume if you plan to use the Holtek decoder you already know what the encoded bit stream looks like? Here is a link for you if you don't already have it:

http://www.linxtechnologies.com/documents/encdecdatastruct.pdf

If you have already decided to use the Holtek decoder on the Rx side, why not use the encoder on the Tx side ...? It uses lots of pins (data to be transmitted is input to the encoder in parallel - say goodbye to 8 pins), but i reduced the micro pin count by using a serial to parallel shift register between the micro and the Holtek encoder.

HTH a little,
Bob