Need some help with RF module

[elamigo]

Hello,
I am new in Radio and Communications. I am trying to established a RF link. But I am not getting what's the problem with my circuit. I have tried this one https://maxembedded.wordpress.com/2011/09/06/rf-module-interfacing-without-microcontrollers/. The circuit is working fine without the modules when I was connecting the Data In and Data Out pins directly with a wire and it worked perfectly. But when I was connecting the modules it was not working. I have approx. 10 inch long antenna with each of them. And my rx contains a CE pin next to DATA pin which I have never seen before. I am not getting what to do with that. please help me.
Thank you

 

[JimB]

And my rx contains a CE pin next to DATA pin which I have never seen before. I am not getting what to do with that. please help me.

You do not give any other information or link to any data about you receiver.

So, as a best guess, CE stands for Chip Enable.
Depending on its polarity, it should be connected to either the +ve supply or the 0v line of the receiver.

Warning, this is just a guess based on experience of other devices, so don't hold me responsible if you "let out the magic smoke" when you try this.

JimB

 

[elamigo]

my rx looks like the same as the yellow one given here. https://ashishrd.blogspot.in/2011/05/building-computer-controlled-wireless.html. I have tried the CE pin unconnected as stated in this blog. But it didn't work. I also got the number written on my rx . It's KST-RX820 and tx is KST-TX01c. Plz tell me what should I do ?????????

 

[elamigo]

You do not give any other information or link to any data about you receiver.

So, as a best guess, CE stands for Chip Enable.
Depending on its polarity, it should be connected to either the +ve supply or the 0v line of the receiver.

Warning, this is just a guess based on experience of other devices, so don't hold me responsible if you "let out the magic smoke" when you try this.

JimB

my rx looks like the same as the yellow one given here. **broken link removed**. I have tried the CE pin unconnected as stated in this blog. But it didn't work. I also got the number written on my rx . It's KST-RX820 and tx is KST-TX01c. Plz tell me what should I do ?????????

 

[JimB]

I looked at the picture of the RECEIVER in your link, I also googled KST RX820 in an attempt to find a datasheet and found a picture of a TRANSCEIVER which looks nothing like it.

Without any more information, there is nothing else I can suggest.

JimB

 

[elamigo]

I looked at the picture of the RECEIVER in your link, I also googled KST RX820 in an attempt to find a datasheet and found a picture of a TRANSCEIVER which looks nothing like it.

Without any more information, there is nothing else I can suggest.

JimB

So what should i do now ??? should I post the picture of my rx tx ??? plz tell ....

 

[trash]

They look like a common LIPD pair that one of our local retailers (jaycar) sell.
They're simple OOK. The first thing is to verify that your TXer is working properly.

You can do this if you have a scanner, tuning it around 434MHz, usually about 434.900MHz and listening for the carrier and any data you might be sending.
You should be sending less than 9600bps because these modules are hard pressed to work even that fast.

If this is ok, then transmitting a carrier only will cause the RX module to activate on it's output line.
Using a 555 timer with 1Hz pulses and an LED on the RX data output to test the receiver.

https://www.electro-tech-online.com/custompdfs/2012/05/ZW3102mod.pdf

The only other thing that stands out is the voltage levels. They might not be TTL levels or whatever you're using.

 

[elamigo]

They look like a common LIPD pair that one of our local retailers (jaycar) sell.
They're simple OOK. The first thing is to verify that your TXer is working properly.

You can do this if you have a scanner, tuning it around 434MHz, usually about 434.900MHz and listening for the carrier and any data you might be sending.
You should be sending less than 9600bps because these modules are hard pressed to work even that fast.

If this is ok, then transmitting a carrier only will cause the RX module to activate on it's output line.
Using a 555 timer with 1Hz pulses and an LED on the RX data output to test the receiver.

https://www.electro-tech-online.com/custompdfs/2012/05/ZW3102mod.pdf

The only other thing that stands out is the voltage levels. They might not be TTL levels or whatever you're using.

Hey thank u for this suggestion. I'm gonna try this out and will post the result soon.

 

[elamigo]

it's not working. hey man does anybody has any other ideas ??? plz help !

 

[trash]

have you confirmed that the transmitter is working first ?

 

[elamigo]

have you confirmed that the transmitter is working first ?

No I don't have a scanner. Do u have any other idea to check the transmitter ???

 

[trash]

You could try building a simple diode RF power detector.
https://www.electro-tech-online.com/threads/simple-field-strength-meter.58/
This field strength meter will work.

Else ordering some back copies of Silicon Chip magazine might help.
https://www.siliconchip.com.au/cms/A_112303/article.html

https://www.siliconchip.com.au/cms/A_110920/article.html

 

[elamigo]

have you confirmed that the transmitter is working first ?

thank you very much. just checking it.

 

[elamigo]

Guess what, I have got a new 434Mhz module. And everything is working fine.