Support Thread for 315Mhz RF link

Product URL: … -p-76.html

The kit is consisted of transmitter and receiver, popular used for remote control.

Basic spec
Frequency: 315Mhz.
Modulation: ASK
Receiver Data Output: High - 1/2 Vcc, Low - 0.7v
Transmitor Input Voltage: 3-12V (high voltage = more transmitting power)

Demo Scheme could be downloaded here: … RFlink.pdf

The popular link is like this: MCU -> Encoder -> Transmitter ------ Receiver -> Decoder -> MCU,

PT2272(Encoder) and PT2262(Decoder) are optional, their existence is to 1)avoid confusing when multiple RF links in range 2) isolate disturbance. You can integrate the encoding and decoding work to the MCUs on both side. Whenever there is no 315Mhz devices around, you may use it as direct cable connection.


Q: Do you have Rx and TX with PT2272 (Encoder) and PT2262 (Decoder) and what is its cost.
A: We have the RX with PT2262 for $4.99, if you are using MCU on both ends, encoder or decoder is not neccessary.

Q: I want to use these with an arduino. What determines the number of channels and codes, is the encoder/decoder (PT2262/PT2272) or the MCU?
A: Both will do. On MCU, you may integrate many encoder/decoder codes for more powerful functions.

Q: What is the scope of this transmitter? (a distance which I can use)
A: 20-30 meters is the usual for indoor use.If you raise the voltage upto 12V and equip it with a 24cm single core straight wire, It will be well over 100 meters in open ground.

Q: I wish to buy a couple of this item. But first of all can you provide the detailed info how do I interface this thing with Arduino? Schematic, program Code etc will be helpful. Thank You!
A: You can treat it as a cable link. Which means you set data to high in TX module, the RX module will output high. Detailed discussions are here: … 19541099/7

I own the ones sold by September 2008. Could you please tell me the pinout for those modules which are different from the ones being sold now. The receiver I bought from you has the pins to the right instead of the left as the new ones.

The ones I have have “CDT-88” printed in the board for the receiver and “CDR03A 2007-09-21” for the transmitter.

Hi Juan:

Would you please send us a photo? We don’t have it in stock to validate them now. I think there should be a silkscreen for its pin out. :slight_smile:


Thank you for your reply. I already figured out what the pinout is. Basically it is the same than the current being sold one.

After connecting the Receiver to an Arduino I have noticed that a lot of noise is being received without any Transmitter sending data.

Is it normal or is there anything wrong with my receiver? Shouldn’t the receive data line keep high until something is received?

Hi Juan:

Did you see the noise by oscilloscope? It should be normal since it is AM. You’d better add an address word to distinguish the signal from the other.


I have just purchased the 315Mhz RF link kit (WLS105B5B) from seeedstudio.
Using it with 2 arduinos as specified in the various articles (tried all schemas).
Can’t seem to get it to work!

I’ve tried every piece of code available, from serial.print to VirtualWire code.

The receiver seems to be working as I’m seeing the noise mentioned in these articles
(and nothing when disconnected).

However, the transmitter does not seem to be working at all.

Pehaps I got a bad one?
Not sure how to test that.

Any help would be appreciated.


re: Got RMA replacements.
Transmitter is now working 100%.
Thank you.