Basic Electronic Help

Hi all, want to use Arduino for a basic task of converting ir to RF to control lighting

At the moment my lighting is controlled by RF but I want to control it using ir and plan to do this using the Arduino and the original RF remote

I know relays can be used making the output switch the relay that can manually "press" the original buttons on the original remote but relays are big and take up space

I would instead like to use a different switching method to "press" the original remotes buttons

Can transistors be used? How would I do this? 12v and 5v supply's will be available for power to power the Arduino and the remote, I simply want to press the buttons

Any help would be appreciated

liamstears:
Hi all, want to use Arduino for a basic task of converting ir to RF to control lighting

At the moment my lighting is controlled by RF but I want to control it using ir and plan to do this using the Arduino and the original RF remote

I know relays can be used making the output switch the relay that can manually "press" the original buttons on the original remote but relays are big and take up space

I would instead like to use a different switching method to "press" the original remotes buttons

Can transistors be used? How would I do this? 12v and 5v supply's will be available for power to power the Arduino and the remote, I simply want to press the buttons

Any help would be appreciated

If all you want to do is press buttons, then we can't be of much help?

I want to control it using ir and plan to do this using the Arduino and the original RF remote

Have the Arduino read the IR signal and send the appropriate RF signal directly. No need to have it "press a button".

Of course, you need to know the details of the RF signal: frequency, modulation technique and code. The general approach is described in this tutorial, but someone may have already done the work for your remote.

I know relays can be used making the output switch the relay that can manually “press” the original buttons on the original remote but relays are big and take up space

I have had a similar application where I wanted to control with an arduino a somfy powered window bilnd.
The somfy remote uses RF codes to control the blinds which I couldnt decode/replicate with the arduino.

So I ended up wiring the actual remote’s push buttons in parallel with the arduino and used a 2N2222 transistor to emulate the remote buttons being pressed on command. The whole setup had to operate at 3.3V which is the somfy remote’s operating voltage.

Watcher:
I have had a similar application where I wanted to control with an arduino a somfy powered window bilnd.
The somfy remote uses RF codes to control the blinds which I couldnt decode/replicate with the arduino.

So I ended up wiring the actual remote's push buttons in parallel with the arduino and used a 2N2222 transistor to emulate the remote buttons being pressed on command. The whole setup had to operate at 3.3V which is the somfy remote's operating voltage.

This sounds like exactly what I am looking to do

Can you please post up schematics and pictures of possible?

One of the issues you get with remotes is sometimes they use a scanning method for reading their button presses, which isn't easy to deal with using transistors. Often this shows up as a rather small voltage
measured with a multimeter (which is too slow to follow the scanning waveforms).

In a 3V remote with 3V measured across the switches, its fairly clear a transistor will do the job.

In fact photo-transistor output opto-couplers are a great idea, as you don't even need to share grounds,
just get the polarity right. They may even work on a scanned key matrix too.

In my case i am also powering the remote from the arduino at 3.3v.

I ll make a schematic later but basically i use one transistor per switch whose base is driven by an ardouino output via a resistor and when turned on, it brings the remotes push button terminal to ground.potential.