Help needed building a radio transmitter/receiver system

[james1204791]

Hello,

I was wondering if anyone would be able to offer any help or advice on a project i'm currently undertaking.

I'm wishing to make one reciever that is able to distinguish between 5 different transmitters. For example if a signal from transmitter 1 is received, LED no.1, if from transmitter 2, LED no.2 and so on.

I have very basic electronics knowledge and have done some research into this area and have found an encoder/decoder chipset that might be able to help do this for me - RF600E & RF600D. The decoder can learn up to 7 different encoders and has a range of up to 20 metres.

I've also found the RF600T which can do a similar thing but also has low battery warnings and it confirms signal transmission.

Apparently these are easy to use chipsets which can be inserted into any RF circuit. This is my problem as I have limited electronics knowledge i was wondering if anyone could help point me in the right direction of a suitable RF circuit or what i would need if I were to design my own.

Any help would be greatly appreciated

James

 

[sigmacom1]

Hello!

First of all, I don't know these chips you are reffering to, so please give some info (URL of datasheets, etc).

There are many ways to do what you want, easy, cheap, etc. Are these chips available, and if yes, what is the total money cost?

 

[james1204791]

Thankyou for your reply,

I'm hoping to keep the cost low, around

 

[sigmacom1]

If you can work with these chips (I say that because of your level of knowledge), then choose an RF transmitter & receiver from http://www.rfsolutions.co.uk/products/rf_modules/Am_fm.htm or http://www.abacom-tech.com/receivers.htm and http://www.abacom-tech.com/transmitters.htm

Some of them are really cheap for you I suppose...
Any questions?

 

[hotwaterwizard2]

Try This Link

http://electronicsworld.tripod.com/remotecontrolsimages/remotecontrolsckt5.html

 

[sigmacom1]

DTMF, huh? Good and cheap solution, but too "classic analog" don't you think? I prefer digital; it's more secure...
Anyway, I think it's perfect for our friend with the level of knowledge he has.

Tips for james120479:
- You can ommit the flip-flops (4013) if you don't want to hold the last state (which transmitter was last used).
- Forget the 418 MHz receivers we discussed earlier. You must use a simple FM radio receiver instead.

 

[Shahriar]

Dear james120479

Use an Encoder IC In Transmitter and a its OWN decoder in receiver. for example PT2262 as Encoder and PT2272 as decoder. and if U are familiar with Microcontrollers U can send different codes and detect them in receiver by another Microcontroller.

For Tx circuit, I should say that it is very difficult to build a very sensitive TX for data sending, The best way is buying a TX Module (i.e. TLP434 as Tx and RLP434 as Rx).

If U want to build your Own Tx, build a several FM Tx and connect the input to different pulses with diffrent frequencies. then detect them by a lm565 (PLL IC). Here what U are looking for. but I recommand the first solution

HTH
Shahriar

circuit17.pdf

 

[audioguru2]

C3 in the transmitter posted by John (HotWaterWizard) should be 10pF, not 10nF as shown. :

 

[Alun]

Yes well spotted 10nf would be an RF short, I would go lower than 10pf I always use 4.7pf.

 

[audioguru2]

The BF494 RF transistor has very low capacitance and needs 10pF in this circuit, if I remember correctly since I haven't seen a BF494 for about 40 years! ;D