Hello all,

I am trying to design a system in which I use a transmitter with a microprocessor to transmit an RF signal on a specific frequency (the frequency and modulation don't matter) to multiple receiver's listening on the same frequency. I want to be able to use very simple receiver radios AM or FM doesn't matter to receive the signal and switch on a relay or even just pull a transistor high to use with switching.

I was considering using DTMF to send codes over the RF signal and decoding them on the receiver. I am trying to avoid using micro-controllers in the receiver end so I just wanted to use a DIP switch and some sort of AND logic to compare the transmitted codes and the DIP switch.

The receiver needs to be low cost as there is a very large margin here for theft as its for use with a public venue.

I am open to suggestions


Recap of project outline:

• Microcontroller controlled (or possibly not) transmitter
• RF (AM or FM or anything any freq)
• Simple radio reciever (same freq as transmitter)
• Reciever initiates a SSR or Relay
• DTMF or any other encoding.
• Low cost receiver

 

Have a look at the hardware on this website.

hgmjr

 

I have considered these module before, but even the cheap modules are approximatly $8 just for the reciever alone without decoder chip. I am considering making 20 - 25 of the remotes for the system and the budget is not very big, this is why I suggested using AM or FM and DTMF but like I said it was just a suggestion. I am still going to consider soe of these modules

Best regards