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Topic: 433 MHz Radio Frequency Kit (Read 10076 times) previous topic - next topic

f.schiano

Hi,

I bought this kit:
RADIO KIT

But I didn't found any example to work with it. I heard about some libraries developed to simplify the comunication with these kind of modules.

do you know something about it?

Thank you in advance,

Fabrizio.
L'impossibile...richiede solo piu' tempo!

CrossRoads

Have you looked into Virtualwire? It has worked nicely for me with other 433 MHz units.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

f.schiano

Are you talking about this:

http://www.open.com.au/mikem/arduino/VirtualWire.pdf

Thank you...

p.s. I would work in Boston, my dream is the MIT ... You are from Boston.. I like it !!! :)
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CrossRoads

That's what I'm talking about.
I work outside of Boston, and go in as little as I can - not really a big city kind of guy.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

f.schiano

I was reading the PDF , and I notice that I have to program both the transmitter and the receiver, So I will need one arduino close to the transmitter and one to the receiver ?

Or can I program the transmitter to send , for example , 2 types of messages , on the basis of what I want?

For example, can I build a transmitter that send a message at the pushing of a button, without an Arduino attached to it?
Thank you
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CrossRoads

Yes, you generally need a uC at one end creating the message to send, and a 2nd at the other end to receive the message and do something with it.
The transmitter only sends out what it sees on its data input, if that's what you mean by programming.
Virtualwire pretty much demands that, as it wraps some bytes around the message being sent to ensure a good message is received.
If you had a clock source and a counter and a memory chip and a shift register then I suppose you could Not have the arduino, and instead read  the data from 16 (8? 32?) addresses out of the preprogrammed memory and sent them via shift register to be transmitted, that could probably ensure a good transmission every time.
Or, buy something like an ATMEGA48A-PU-ND for $2.58 (digikey price), plus a crystal, 22 pf caps, and a couple of Rs & Cs for some more pennies (dipmicro price)  and a bit of perfbooard to put it all on  and save yourself a lot of aggravation and have a design you could expand with later.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

CrossRoads

This is another method to consider, don't know if you had found this or not.

http://arduino.cc/forum/index.php?topic=51225
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

sui


For example, can I build a transmitter that send a message at the pushing of a button, without an Arduino attached to it?


Well, as said you'll need a microcontroller.
But there are a lot of cheap 433MHz remote controls for power sockets and similar devices around. Most of them just send a 4Byte value and you can receive and decode that with a Arduino + your receiver.
=> http://code.google.com/p/rc-switch/

f.schiano

Sui thank you for the answer, if I had uderstood your concept, I think that the whole thing will be something like this:

ARDUINO+RECEIVER RF 433MHz close to the thing that I want to activate if I receive a kind of signal.

TRANSMITTER RF 433MHz, that could be a remote controller like this:

In this way I have to understand what is (for example) the message sent by the remote controller when I press button 1, and then I can use the transmitter without wasting another arduino close to it.

Sorry for my bad English, thank you

Fabrizio.
L'impossibile...richiede solo piu' tempo!

sui

Typically they send a 24 bit value - in other words just a number between 1 and 16777216 depending on which button you've pressed.

You can find a example here: http://code.google.com/p/rc-switch/wiki/HowTo_Receive

The cheap systems (= the power sockets you find in do it your self stores) are allways sending the same value when pressing the same button but security relevant remotes (= car or garage door locking systems) often use a rolling code algorithm and therefore allways send another code on each keypress. Nevertheless if you have a 433Mhz car key you could give it a try with the libary :)

sui

PS: another cheap and simple way to control a Arduino are infrared remotes

=> http://www.arcfn.com/2009/08/multi-protocol-infrared-remote-library.html

f.schiano

Thank you sui.

Can you post, for me, some links for some controllers of these?

p.s. In these days I was trying to let work some infrared sensors, to start understanding if Infrared could be the way to resolve my problem ;D!!!

bye
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Ledfreak3d

see my post in the Domotica topic for more rf stuff

f.schiano

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sui

oh, sorry. didn't look into this topic for some days... here you are:

http://www.pollin.de/shop/dt/NjAzOTQ0OTk-/Haustechnik/Installationsmaterial/Schalter_Steckdosen/Ersatz_Fernbedienung.html

http://www.pollin.de/shop/dt/MzMzOTQ0OTk-/Haustechnik/Installationsmaterial/Schalter_Steckdosen/Funk_Steckdosen_Set_2605.html

http://www.conrad.com/2-part-radio-switch-set-433-MHz.htm?websale7=conrad-int&pi=646443

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