cstout:
This thread has really made me hopeful, but unfortunately I'm left with a lot of questions after reading through it. It appears this is one of the only threads that turns up in Google that matches the same project I'm working on. I have a 350MHz Hunter remote for the ceiling light and fan. I have one in each room in my house and my goal is to remotely control through the Arduino.Mysticle31, would you mind posting what your final code was to make this work? I've read up a lot on using a 315MHz or 434MHz receiver for obtaining the codes for various RF controls. My problem is, I've yet to find a sniffing solution that is working with my 315MHz receiver. I'm suspecting that there is a communication problem with the frequencies being different, but I've read that it should work by adjusting the 315MHz receiver. The back of my 315 shows three different frequencies: 315, 330, 433. I'm not sure what that means though. Did you need to get a 350MHz receiver to get the codes for your fan's remote?
Thank you very much.
Forget the 350mhz frequency
I think the best way is to forget 350mhz frequency and look for other bypass method.
Why? because 350mhz is rarely seen, for the transmitter part, now the transmitter between 315 - 433 range or similar are all using SAW resonator, which is fixed frequency, not the old transmitter whose frequency can be adjusted by coil or capacitor.
A simple photo of current transmitter can be found at http://blog.solidremote.com/post/identify-rf-remote-control.aspx
And for the receiver part, the old super-regenerative receiver's frequency can be changed by adjusting the variable inductor on board, but nowadays super-het ones are using crystal stabilizer, which means not possible to change frequency unless you change many components on board - which also involves re-design and tuning.
If you're interested, there is a smarter way of adjusting frequency on modern transmitter chips, such as Silabs 4010, the frequency can be changed by configure the software, and can be changed from 27-960mhz, and also can switch between AM/FM, of course, there involves board parameter change also to achieve maximum output power.
Si4010 is truly great, to achieving so many feature in so small package and low cost! worth learn more.
Attach Ardunio to original transmitter board
In this way, you just simply remove the original buttons / or connect side-by-side on transmitter board, and use arduino output ( or via relay ) to simulate button press ( just simple on/off in circuit ), so everything works just same as before, the only difference is, arduino instead of fingers.
Hope it helps.