Decoding RF 433 with RCSwitch failed

Projects Networking, Protocols, and Devices
1

Dear Forum,

I'm trying to decode a remote switch with the RCSwitch Lib. As a receiver I'm using an MX-05V on pin 2 of my Uno, but didn't get any serial response.

To try if the MX-05V is brocken, I wired the data pin to an analog pin A0 and read and printed them the serial. I got a wired response with values from 0 to 765 even without pressing on the remote switch. I use the following code for that.

unsigned int data = 0;   // variable used to store received data

void setup(){
   
   Serial.begin(9600);
 }

void loop(){
   data=analogRead(A0);    //listen for data on Analog pin 0
   
   Serial.println(data);

 }

Does any body have an idea what can be the issue?

Thank you in advance,
René

2

They are cheap receiver modules and tend to put out random data unless it picks up a signal so it's probably not broken.
What remote switch are you trying to decode as RCSwitch might not work with your remote.

3

Open the remote switch and try to read the numbers on the chip :wink:

4

I found the following hint, that help me partially. With that im able to receive one of my 3 remotes. A no-name one. Home easy and intertecho failed.

Change:

unsigned long delayTolerance = delay * RCSwitch::nReceiveTolerance * 0.01;
to
unsigned long delayTolerance = delay*0.8;

in RCSwitch.cpp in folder "libraries\RCSwitch". It appears 3 times.

5

Home Easy start page : Arduino Playground - HomeEasy
An older basic intertechno device should be compatible with RCswitch.

6

Thank you Peter.

Unfortunately I didn't get any of the sketches from the HomeEasy playground working. So I starte to low level read the the data from RF433. I found the pattern and was able to isolate them.

7

Try to use original example sketch from RCSwitch
and connect the receiver to interupt 0 (on nano is this pin D2)

#include <RCSwitch.h>

RCSwitch mySwitch = RCSwitch();

void setup() {
Serial.begin(9600);
mySwitch.enableReceive(0); // Receiver on inerrupt 0 => that is pin #2
}

void loop() {
if (mySwitch.available()) {

int value = mySwitch.getReceivedValue();

if (value == 0) {
Serial.print("Unknown encoding");
} else {
Serial.print("Received ");
Serial.print( mySwitch.getReceivedValue() );
Serial.print(" / ");
Serial.print( mySwitch.getReceivedBitlength() );
Serial.print("bit ");
Serial.print("Protocol: ");
Serial.println( mySwitch.getReceivedProtocol() );
}

mySwitch.resetAvailable();
}
}

8

Hi,
I also get nothing on the monitor,
I am using exactly the code pasted above (basic receive) on an r3 UNO.

the fobs are 433mhz, can even be seen on rtl-sdr

I can serial.print the raw pin data also, which clearly picks up the fob, but the example code does not display anything?

is it not picking up the interrupt?

thanks!