Welcome to the world of RF.  An easy way to ignore noise is send a
difficult-to-duplicate prefix character before each data character.  I
commonly use 0xF0 or 0xAA (for larger packets, 0xFF 0x00).  Ignore data
until this prefix character is received.  This is not 100% reliable, but
it's not bad.

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> From: Sylvain Bilanger <eldamir@HOTMAIL.COM>
> To: PICLIST@MITVMA.MIT.EDU
> Subject: CRC?
> Date: Tuesday, August 18, 1998 9:20 AM
>
> Hi,
> I'm trying to do some RF comm.What i'm triing to do is send a ASCII
> caracter every seconde. My problem is that i the following:
>
> First I transmit 7 bits with a Pic to a transmitter (all in asynchrone
> comm)... After i check for the data at the recepter everything is fine
> there. The pic gets good data... But the problem is when i'm not sending
> any data... The RX module keeps on receiving data... What can i do to
> ignore this data. I tried parity but it's no good, because the bits keep
> on flipping and the noise does'nt help... Should i use CRC? If so can
> anyone give me an example.
>
> Thanks
> Sylvain
>
>
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