Capture raw RF 433Mhz signals without sound card

Projects General Guidance
1

I would like to use arduino and RF 433Mhz receivers to capture RF signals from any RF remote control.

I actually can capture signals by using sound card input, record them with some sofware (audacity) and then generate the sequences to send them again, and it works OK.

But what i want to do is to build a RF signal "learner", without the use of a sound card pc to get the signals.
This learner has to be generic enough to read RAW codes and then playback them again.

Can you guide me on how to achive this?
Best regards and thanks in advance.

2

What RF remote ? Post some information about the remote that gives the specs.

3

I would like to capture signals from any 433Mhz remote, not any specific remote.

I would like to:

  1. Capture signal from any 433Mhz RF remote and store into arduino (by using a 433mhz RF receiver).
  2. Playback the signal by using a 433mhz emitter.
4

Show me an 433Mhz RF Remote.
Produce one.

5

I suspect he means a garage door remote.

Of course, most of the new ones change the code each time the remote is used.

6

Are garage door remotes 433 Mhz ?
What is the definition of an RF "learner" ?
How does that work ?
(I'm afraid to ask why anyone would want such a thing)

7

I actually can capture signals by using sound card input

How do you capture RF signals with a sound card?
What are you using as a radio?

Pete

8

Is not for a garage door remote.
I have several remote sockets (this ones: http://www.tkbhome.com/?cn-p-d-91.html)

I actually capture the RF signal with sound card, using a circuit like this: Interface with Remote Power Sockets – Final Version « RAYSHOBBY.NET

what i need to do is to capture the signal directly with arduino, and then send from arduino that signal.

9

what i need to do is to capture the signal directly with arduino

The problem with that approach is that the cheap 433 MHz receivers output full scale noise when they have no signal. With Audacity giving you a nice trace of the receiver output, it is easy (for a human) to distinguish the RF remote signals from the noise, as well as to determine the pulse on/off timing. For an example, look at the beginning of the Audacity output (blue trace) on this page: Interface with Remote Power Sockets – Final Version « RAYSHOBBY.NET

It is very difficult to write a computer program recognize an arbitrary RF signal. The IR decoder programs work because IR receivers tend not to output full scale noise in the absence of a signal, and it is possible to put some constraints on what a "signal" should look like.

10

raschemmel:
Are garage door remotes 433 Mhz ?
What is the definition of an RF "learner" ?
How does that work ?
(I'm afraid to ask why anyone would want such a thing)

Seems to be moot for this discussion, but my car has one. You put the in-car unit into learn mode and press the garage door remote so that it can learn the signal. Then you can use the in-car remote to operate the garage door.

11

Sound cards have been used for a long time as a simple oscilloscope setup for decoding IR remote codes and similar.

https://www.google.com/search?num=100&lr=&as_qdr=all&q=sound+card+oscilloscope&spell=1&sa=X&ei=8ZeoU6SsIMu3yATktIGQAg&ved=0CBwQvwUoAA&biw=1184&bih=607

12

Its quite common for garage door openers to use 433.92 Mhz , but most of the openers are rolling code transmitters
which means that you cant easily learn the code, as it changes everytime you push the button on the opener.
Making a universal 433 Mhz receiver is pretty impossible as theres no standard as to how the manufacturers of the transmitters have to encode the data so no way to figure out where the data stream starts and stops.

13

Take a look at the RCSwitch code (I think its on google code)

It has an advance read example, which just displays the binary data of any valid signals it detects.

It doesn't work for all 433 remotes but it does work for a lot of them.

It can also Send the binary data, so it would be possible to build something to record and playback the codes.

This does however sound a lot like some form of hacking (I remember doing something similar years ago when cars had IR alarm systems, using a "learning" remove control)

14

I also have some remote-control outlets that operate at 433MHz. They are readily available and cheap at Christmas time from Walmart and HomeDepot. It's good that they work on a radio signal, since it allows you to place them behind furniture. They look very similar to your TKB-Home outlets.

But I have a Pronto programmable universal remote that controls my whole theater system. It's an older one and only does infrared, not RF, so I couldn't use it to control my lights. Bummer!

I hooked a 433MHz receiver up to the Arduino, ran a logic analyzer sketch, and captured and analyzed the format of the RF signal. SUMP compatible logic analyzer code for Arduino. - Interfacing w/ Software on the Computer - Arduino Forum

Then I hooked a 433MHz transmitter up to the Arduino, and an infrared receiver, and used Ken Shirriff's library to receive and decode a infrared signal from the Pronto, and retransmit a related code over RF to the remote-control outlets.

Viola! I can now turn my RF-controlled lights on and off with my infrared universal remote via the Arduino!

Have you opened one of your outlets, or the remote up to see what is inside? If they use a AUT980202 chip then I have already decoded the protocol for you and I will be happy to share my code with you. I would not be surprised if they do use this same chip.

15

I have managed to receive an RF signal from my remote (without using a sound card or library) - just using an Analog input, and have also managed to reproduce the signal - and transmit it to my Fan/Light using a 433MHz transmitter.

I hooked up a sound sensor to the Arduino (just for fun), and turned it into a clap activated fan/light.

I am in the process of documenting and blogging about my process.
My first tutorial can be found here:

I hope this helps you to get started.