Problem capturing 433mhz remote codes

Projects General Guidance
1

Hello,

Thanks in advance for your help.

I'm building a project where I need to capture the codes transmitted by my existing 433mhz remote controls for things like shades, led light strings, etc.

So far I have not been able to observe any codes being captured in the Arduino Serial Monitor.

I have the Arduino IDE installed on Windows 10

I am using a Genuine Arduino Uno which is powered by the USB port on my laptop

In the IDE I have selected the "Arduino/Genuino Uno" board selected

When connected the board is on Com 4

I have the installed the provided rc-switch library from the Manage Libraries function (rc-switch by sui77 v2.62)

So far I have tried 2 of the example rc-switch sketches (ReceiveDemo_Advanced and ReceiveDemo_Simple). I have made no changes to either of these sketches before uploading to the Arduino.

I am using a basic (cheap) 433mhz rf receive module I purchased on Amazon in a pack of 6 transmitters and 6 receivers. The receiver has 4 pins (Ground, Data, Data, VCC)

My connections are pin to pin with no breadboard as follows:
Arduino Ground to RX Ground
Arduino 5V to RX VCC
Arduino Data Pin 2 to one of the RX Data Pins

I connect the Arduino to my laptop with a USB cable and then load the the sketch to be tried, verify that the proper board and com port are selected and then upload the sketch.

After the sketch is compiled and the upload has completed I open the Serial Monitor and then hold one of my remote controls very close to the rf receiver and press one of the buttons (usually the "on" button). I then look at the Serial Monitor to see if any rf codes have been captured.

And, up to this point nothing has happened. Well I did capture a transmission twice but was unable to repeat that momentary success.

Any help you might be able to send my way would be greatly appreciated. I need to capture these codes so that I can move on with my project.

If you have an alternate way for me to accomplish this I am open to all suggestions.

Thanks so much!

2

Have you connected antennas? :slight_smile:

3

I hate to admit it but I have not.

I plan a trip to get some wire tomorrow and make an antenna.

I'm thinking bare 14 ga copper about 27 mm long.

Does that sound about right?

Thanks!

4

Hi,
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html

Are you sure you remote is 433Mhz?

If you hold them too close you will overload the rather simplistic Rx and not get anything.

Can you post a link to the Tx/Rx units you bought please?

Also, check the Serial.begin( ) statement in the code and make sure you have the serial monitor in the IDE set on the same speed?

Thanks.. Tom.. :slight_smile:

5

433.92 MHz
17.28 cm / 6.80 inch

315 MHz
23.81 cm / 9.37 inch

Simple 30 AWG wirewrap wire worked ok in my projects.

6

The biggest problem usually trying to decode unknown 433 Mhz transmissions is what kind of remote is it.
Rc switch only decodes the data format from PT/SC2262 data encoders, which while being quite common are not the only type.
You can sometimes guess whether RCswitch will work or not, by looking at what the remote does.
If its a turn something on or off type function, then there is a good chance that Rcswitch will work.
If however its a hold the remote button down and something happens until until the button is released type function, then its unlikely to work.

7

Hi,
The wire does not have to be bare, insulated wire works just as good,

Tom... :slight_smile:

8

TomGeorge:
Hi,
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html

Are you sure you remote is 433Mhz?

If you hold them too close you will overload the rather simplistic Rx and not get anything.

Can you post a link to the Tx/Rx units you bought please?

Also, check the Serial.begin( ) statement in the code and make sure you have the serial monitor in the IDE set on the same speed?

Thanks.. Tom.. :slight_smile:

Thanks so much for the tip on reading the first post. I have now done that.

I checked to make sure that both the Serial.begin( ) statement in the code and the Serial Monitor are set to the same value (9600).

I appreciate your help with this.

Thanks,
John

9

CrossRoads:
433.92 MHz
17.28 cm / 6.80 inch

315 MHz
23.81 cm / 9.37 inch

Simple 30 AWG wirewrap wire worked ok in my projects.

Thanks so much for the spec on the antenna. I should have tried that from the get-go.

I'll complete that step today and let you know how it goes.

Thanks!
John

10

mauried:
The biggest problem usually trying to decode unknown 433 Mhz transmissions is what kind of remote is it.
Rc switch only decodes the data format from PT/SC2262 data encoders, which while being quite common are not the only type.
You can sometimes guess whether RCswitch will work or not, by looking at what the remote does.
If its a turn something on or off type function, then there is a good chance that Rcswitch will work.
If however its a hold the remote button down and something happens until until the button is released type function, then its unlikely to work.

That is an excellent point and one I almost overlooked. While doing the research for the project I noticed the RF chip sets supported by the rc-switch library and subsequently cracked open each remote to verify that the chip set was supported. And lucky for me all of the remotes except for one have a compliant chip set.

And yes, for each remote a simple button push is all that is needed to effect the desired result. One button for "on" another button for "off". Once button for "up" another button for "down". Or, push the same button sequentially to change colors.

Thanks for you help with this.

John

11

I have used the Hobby Components 8 Channel Logic Analyser with 433Mhz and IR codes to help determine protocols.

Great little device for £10 and freeware.