What is the afforadable and acurate way to decode 433mhz wireless data ?

Question

Hi,

Simply looking for a way to capture, copy and then trigger wireless data from an arduino. I wish to get all the wireless devices in my home to be control from a single remote, so I need a scanner that would give me all the data, right now it give me more headache than data.

1- I've google ''Packet Sniffer'' and found the Texas Instruments SmartRF but the module is over 500$, which is pricy for me since I would do this only ONCE.

2- I've spend quite lot of time trying to get signal from my Garage Door opener with and arduino and RF module, but the information capture is NOT ACCURATE.

(*seem like the arduino RF library can't do an accurate work or the Receiver not compatible with some remote I have)

So is there another way ?

Someting more simple and accurate.

Thanks for any suggestions, help or comments.

neilk · Accepted Answer

No, it's not an error! I thought this: https://github.com/sui77/rc-switch/wiki/HowTo_Receive was self explanatory thus: Connect a receiver to Pin #2 of your Arduino. Upload the ReceiveDemo sketch which is provided in the library. Open the Serial Monitor (9600 baud) Press any key on your remote This should give you a decimal value which represents the binary pattern decoded by the sketch. Then you move on to use that decoded decimal value in the SendDemo code I provided. If you can't get the ReceiveDemo sketch to work, then try the advanced version. If that fails then I begin to wonder if your receiver is working? I don't have the seedstudio kit, but I do have a transmitter/receiver pair I bought very cheaply on eBay. Do you have a 'scope? If so you should be able to monitor what the receiver is outputting onto pin 2 of the Arduino, when you press a button on the remote. Btw, when the remote is NOT transmitting, you will probably see a lot of random noise from the receiver. Neil

kas.lewis · Answer

What you are essentially trying to do with your current setup is to use a generic postcard reader and want to understand what the postcard says but your forget that there are different languages around teh world. With RF it is the same thing. Just because the device uses 433MHz does not mean it speaks the same language. The 433MHz is like it all being written on paper but there are different languages. What you need it to know the RF protocol as well as packet structure of each device. one without the other will only get you so far and probably nowhere useful. Also the TI kit probably won't help because again you need to know the RF encoding. A spectrum analyzer with a decent number of decoding protocols might help but again you would need to know how to use it and where to start. While what I'm saying probably won't help you get to your goal it might give you an idea of what it is you are looking for. Good luck with your project Kas

neilk · Answer

Hi redgreenblue . I have been quite successful using the RC switch library: https://github.com/sui77/rc-switch/wiki https://github.com/sui77/rc-switch/wiki I've used an Arduino and a 433Mhz receiver, with this library, to decode the transmissions from a remote control unit and then set up an Arduino to control a 433Mhz transmitter to switch on a remote socket. It takes a bit of fiddling with, but it's not too difficult. Hope this helps Neil

neilk · Answer

This is the approach I used: https://github.com/sui77/rc-switch/wiki/HowTo_Receive to decode the signals from my remote: I then used this sketch to transmit a code to my device: /*
 Send the code sequence for the printer OFF
 Based on SendDemo example in RCswitch library
 
 http://code.google.com/p/rc-switch/
 
*/

#include <RCSwitch.h>

RCSwitch mySwitch = RCSwitch();

void setup()
{
 Serial.begin(9600);
 
 // Transmitter is connected to Arduino Pin #10 
 mySwitch.enableTransmit(10);

// Optional set pulse length.
 mySwitch.setPulseLength(308);
 
 // Optional set protocol (default is 1, will work for most outlets)
 // mySwitch.setProtocol(2);
 
 // Optional set number of transmission repetitions.
 mySwitch.setRepeatTransmit(40);
 
}

void loop()
{
 mySwitch.send(2406631, 24); // switch printer OFF
 delay(5000);
} where 2406631 is the value I had decoded earlier. I also tried it with 2 other different remotes, successfully decoding their transmissions and then using the simple transmitter to replace the remote. I didn't use any other files or libraries, and I didn't use an antenna on either receive or transmit, but I was only separating them by a foot or so. Hope this helps Neil

redgreenblue · Answer

Gee! I wasn't aware there was criminal using this...don't worry my friend I'm doing internet of thing for my home I guess I'm getting pretty crazy about decoding everything...tv, garage door, ceiling fan, heater, lights, etc.. A 'rolling code' ... , there is so much about RF to be learn, very cool. That's a valuable information THANKS.

Former Member · Answer

Most cars use wireless to unlock their doors these days... Luckily they have invented methods (such a rolling codes) to make it difficult for would be criminals!!!

redgreenblue · Answer

I purchased a RTL-SDR USB dongle that work with SDR sofware. I expected to do exactly what you show up here.

But I have not been able to make it work this way...all I get is signal that look like 'wave' form in which I cannot see the low and high of the signal.

Your PicoScope seem to be exactly what I need!

I've found numerous products when google ''picoscope'' but simply to get things faster,

Can you give me more informations on which PicoScope I might need ?

I'm new user to any kind of USB dongle that record, translate or interpret signals.

So any advices from you Neil would be deeply appreciated!!

Are you an hobby or professionnal electronics engineer ?

What is the afforadable and acurate way to decode 433mhz wireless data ?

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