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View Full Version : Any encoding-decoding example PIC12F635?



financecatalyst
- 26th July 2009, 04:26
Hello
Is there anyone who can help me with the code for encoding/decoding serial data between two 12f635. I am making an remote control using RF Modules and would like to have some kind of security or code changing feature to keep it safe.

Upto now I just use serout command and send predefined data out.
Thanks in advance

dhouston
- 26th July 2009, 15:24
Why do you need to encode the data? Anybody can capture and replay them and if they are remote control codes, whether encoded or not, the replay codes will do the same thing as the originals. Security requires rolling codes that change with each transmission so replays are ineffectual. Microchip, Holtek and others sell rolling code encoder/decoder chips for this purpose.http://auto.howstuffworks.com/remote-entry2.htm
http://en.wikipedia.org/wiki/KeeLoq
http://www.holtek.com/english/tech/appnote/uc/pdf/ha0121ev110.pdf

In fact, the chip you are using has a Keeloq Compatible Cryptographic Module. Take your banker along when you discuss licensing.