totally new to this

[JohnEnglish]

Hi guys,

I'm new to this field but not new to RC or electronics.

I'd like to build an RC helicopter that I can control via my computer. I'd also like it to have a video camera and a GPS unit on board.

My main issues right now are what type of transmitter/receiver to use and the best way to have the computer - RC interface.

I'm posting this in the UAV section, even though it will be controlled, simply becuase I figure you guys would have more experience with building the necessary computer control systems.

For control, I figured it would be more flexible to have a small computer based system (like Gumstix) to control the helicopter as opposed to sendthing the commands to a control system and then having that interface with the standard RC controls.

Transmitters/receivers - I've seen some people mention using a wifi system. What kind of range do you get on that? Is this the best solution? (it seems to be the easiest).

I'm really looking for pointers on where to start looking for answers. Am I asking the right questions? I'm not sure I know what I need to look for.

[rich smith]

DIY 2.4ghz RC control via PC:

http://www.rcgroups.com/forums/showthread.php?t=1041252

[JohnEnglish]

DIY 2.4ghz RC control via PC:

http://www.rcgroups.com/forums/showthread.php?t=1041252
Woah, thanks. :) It didn't occur to me to look in that forum.

What kind of range are you getting I noticed you mentioned "a few yards" with the 2.4 system. Is that still the case?

I really like the flexibilty of the system, you mention GPS and photography which is what I would like to do with it.

[rich smith]

Woah, thanks. :) It didn't occur to me to look in that forum.
What kind of range are you getting I noticed you mentioned "a few yards" with the 2.4 system. Is that still the case?
I really like the flexibilty of the system, you mention GPS and photography which is what I would like to do with it.

I'm currently reliably and repeatably getting about 3 miles with 900mhz and about 1 mile with 2.4ghz XBee modules. Light, cheap, and draw very little power. Some people are getting up to 20 miles with Aerocom and other long distance modules. Too heavy, too expensive, and too power hungry for my application.

"Few yards" probably referred to comments about WiFi.

[JohnEnglish]

One question I had is what is how is actual vehicle controlled? How are the commands from the computer "translated' into actual movement of the servos and everything else?

[rich smith]

One question I had is what is how is actual vehicle controlled? How are the commands from the computer "translated' into actual movement of the servos and everything else?

In my case single character commands are sent from a terminal program like Windows Hyperterminal. They are translated into movement by the Tiny AVR chip on the plane. Other software can be used to do other functions but you must either be proficient in Windows programming or use the special robot software discussed in the thread.

[zlite]

One question I had is what is how is actual vehicle controlled? How are the commands from the computer "translated' into actual movement of the servos and everything else?

The onboard computer generates a Pulse Width Modulation signal on each of its output pins that are connected to a servo. That's the same signal that a RC receiver uses to control servos.

[rich smith]

The onboard computer generates a Pulse Width Modulation signal on each of its output pins that are connected to a servo. That's the same signal that a RC receiver uses to control servos.

Thanks Chris, I should have filled in that little detail. :)

[JohnEnglish]

Alright, I'll read up on this and will be back with more questions. :) Thanks very much for all the help so far.