Hi,

Please have a look at the following URL

http://www.radiometrix.co.uk/



-----Original Message-----
From: PIC development <pic@BEOWULF.DEMON.CO.UK>
To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
Date: 12 January 1998 21:35
Subject: Re: Coding_for_RF_Data_Transmission


On Mon, 12 Jan 1998, C. Muehlbach wrote:

> Hello all,
>
> i should realize a RF data transmission with 8 or 12 parallel bits, I
> whanted to use the MM57C212 Coder/Encoder from National, but this part is
> replaced by a COP87L42CJ.But I couldn4t recieve this COP in Germany, there
> is a little problem with National.
> So I thought of using a PIC for the Coding/Encoding, the RF module can
> handle frequencies between 300 Hz and 5 KHz.
> So my question is there anywhere an application known or a bit of code
> which could be useful for my application, or has anyone a source for the
> desired National parts.
>
>
>  Christopher M|hlbach
>
>
Christopher,

I have recently started playing around in this area for a work project.
I am using some 2 terminal 418MHz A.M. Tx / Rx pairs that are designed
for car door locks.
At first I just tried sending ASCII at 1200Baud, but I got a lot
of false triggers due to noise pickup in the receiver.
Now I am using a pulse width modulation, sending 3 bits per data
bit at 1200 bits/second, giving me a data rate of 400 bits/second.
This is encapsulated into a 32 bit packet (8 check bits).
So far this has been quite reliable.

Pete