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Fredrick
- 2nd March 2008, 18:31
I have a friedland wireless dorrbell that working on the 433.92 MHz band.

How do i do (if itīs posible) to send someting via the Parallax 433.92 RF module that makes the dorrbell to sound?

I have tryed to listen via the parallax RX module and recive whats come in in 6 byte variabels but how do i know what to send?

http://www.friedland.co.uk/PDF/product/wirefree_chimes_pushes.pdf

dhouston
- 2nd March 2008, 20:15
Look at the output of the receiver on a 'scope (or soundcard as I've suggested before) and merely duplicate the waveform with your transmitter. That brand is one I haven't seen but most use a very simple protocol.

Fredrick
- 2nd March 2008, 21:35
I can see the output on the scope but i donīt understand how to translate it o PBP code and send it via the parallax transmitter.

dhouston
- 2nd March 2008, 22:34
I have no idea about the Parallax transmitter (maybe you should be asking on a Parallax forum) but you need to measure the durations of the pulses and spaces and just duplicate them on output. With a PIC and the less expensive transmitters I prefer, I just use PulsOut, as demonstrated in my example in the Code Examples forum.

Fredrick
- 3rd March 2008, 00:09
The parallax RF modules i based on the LINX chipīs

Yes i can se the output on a scope but how do i translate it to a PBP code?

Archangel
- 3rd March 2008, 05:50
The parallax RF modules i based on the LINX chipīs

Yes i can se the output on a scope but how do i translate it to a PBP code?
Hi Fredrick,
I believe you will have to modulate it in some fashion, easiest and noisiest way is AM, FM is better, less noise, and finally you could pulse the output, likely the least reliable.

BobP
- 3rd March 2008, 13:06
Hi Fredrick,

The code is hopefully not to critical....

The way I would start is to measure the smallest pulse and use this as the clock.
Set up one of the timers to interupt at this interval. Then just clock through 8 bit (byte) numbers that match the waveform.

ie. $8A = 10001010

BobP