Is there software that can function as a transmitter? You could have it output to an antenna from your USB or something. I've searched for an hour or two but have found nothing.

What are you trying to do?

Maybe you could connect through the buddy box port on an existing transmitter.
Anyway you will need a radio that can talk to an airplane receiver.

I would get a cheep transmitter from HK and hack into it.
Make some sort of interface to the computer usb or com port.

@Ranandar
I'm trying to avoid buying a transmitter, because I don't see why it wouldn't be possible for computer software to generate the radio signal.

You'd use the keyboard/mouse as inputs, the software would generate the signal, and an external antenna (connected via USB or Firewire?) would be used for range. Software could easily "tune" to the correct frequency to match the receiver in the RC vehicle.

It would be extremely difficult to fly this way, though, and it would require you to bring a laptop with you to go flying.

There's no reason it wouldn't work, but there's also no reason to do it when a proper transmitter is all-around a better way to go.

Are you trying to avoid the cost, or is it just an intellectual pursuit?

@TP16
I'd like to avoid the cost, & I'm really interested in the idea. I would prefer to have the laptop near because I'm interested in using a camera for FPVing anyways.

It's strange to think that it would be somehow worse than using a Tx. My computer is pretty up to date and fast. Why would a conventional Tx do a better job than a computer?

I though maybe you were going to test servos.

You can't hook an antenna directly up to a digital I/O line.
You need some sort of radio.
Then the computer controls that.

If it's cost then get a HK radio and tell us how it works for you.

I suppose if I tried to get some analog conversion equipment (for the antenna) it would defeat the purpose of avoiding the Tx cost.

One more thing. I'm new to RC equipment brands/names, so what is HK?

Thanks to all for the help.

Maybe this is what you're looking for?

http://www.robotcombat.com/products/BG-BlinkRC.html

"BlinkRC is the smallest, most-capable WiFi remote control receiver. A tad larger than a pack of gum, with BlinkRC you can control most any RC car, plane, or boat with your smart phone or PC. If you're not satisfied with our custom controllers, create your own controller using BlinkRC's open communications protocol."

HobbyKing

I may have a use for that rafe_b.
Thanks for the link.

It has nothing to do with the computer's speed; it's the actual inputs and how you're controlling the plane.

Have you ever flown before?

First, a normal transmitter is designed specifically to fly a plane. Just using the mouse and keyboard would result in very little precision as far as how the plane is flying. You've got one reasonably proportional two-axis input with no centering tendency and then a bunch of bang-bang buttons. Remember, you'll need at least three channels to properly fly a plane, and the mouse will only give you two at most.

Next, you can get a 6-channel transmitter for $23 from HobbyKing. It's not the greatest system out there, but it'll work...

What you're trying to do sounds good now, but once you get into it you'll start to realize how tricky it is...

Here's another option: an inexpensive four-channel analog output module driven via USB:

http://www.phidgets.com/products.php?product_id=1002

Wire this up to an inexpensive RC radio of your choice, in place of the gimbal pots.

I got the FlySky FS-CT6B 6 channel transmitter for $35 from hobbypartz. It's a 2.4GHz frequency hopping transmitter with 3 mixes, dual rates, analog knobs that can be mixed in to control flaps, etc. It's predecessor is the FS-CT6A which I believe doesn't do the freq hopping? You might want to research to see which of these two radios HK rebranded as the $23 T6A mentioned above. The receivers are very inexpensive.

I got my 6B due to good experiences posted online and it seems to work just fine for controlling my 40" Multiplex MiniMag thus far.

While the data/protocol can be managed digitally, the radio frequency signal is analog. You can't just magically create a 2.4GHz signal without a radio transmitter.

I've flown the Parrot AR Drone with the iPhone but found it cumbersome to say the least. There was no way to get the precise control that you get from a transmitter stick. Thankfully it was slow enough to react that it didn't matter much. How much range can you get from wifi controls?

Maybe a computer gamer could, but I felt uncomfortable without the precise control of my transmitter sticks.

Azarr

Thanks for all the replies and information. I see why the analog Tx is better.