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View Full Version : Time to throw out my TX :)


zozie
08-07-2008, 11:56 AM
Well after 3 months of nonstop research and coding it is finally done. My plug and play control system that will work on any plane/heli that allows you to control your machine from your computer with a joystick. I know your first question: What for?
Because I find when I go shooting, sometimes the sun is in my face, hard to get a nice view of the heli. Problem solved. I now control my heli from my laptop with a joystick
Items used:
8 channel serial servo controller
1X Serial radio modem with 40 mile(!) range
1X USB radio modem with 200KB/sec transfer speed with 40 mile range.

I'd prefer not to get into details about the modem used at this point but it's the biggest one you can get without a radio license
I always had this idea in my head but didn't really know where to begin then I had a picture in my head
Advantages: You have a 40 mile radio range with virtually no interference. I've tried to get it to glitch but it won't. The modem uses about 50 frequencies at the same time and verifies the state of all servos compared to the joystick 1000 times per sec. I work at an int'l airport where you get a lot of radio signals and it ranges checked perfect for 3 kilometers and missed 1(!) bit from 2 gigs of data which is impressive in my opinion.
Anyways coding all this toke me about 3 months. I scratch built a program to convert signals from my serial port that my servos can understand. (fairly straight forward using c#/c++)
This is where it gets funny. You could use Micro$oft's directX library to program the joystick, but I opted for a cross platform solution so I hard coded my USB joystick using ANSI C, so It also runs on Linux or a MAC. I am using DirectX in the video due to the fact that most people use Windows and this way you can even use an XBOX controller if you like. Not sure about that you can
The data I'm sending over to the rx of the modem is encrypted using 256 bit encryption so even a hacker with nothing better to do would have a hard time crashing it....
So now finally it's al ready, I'll be test flying it this weekend. The servo response time is acceptable, may not be as fast as a DX7 but certainly faster than my 9C. I pretty much wrote all the mixing functions one could think of as well. CCPM(3-4 servo) mechanical......
Info like gyro gain is delivered every mili second and in-flight adjustable amongst other things. I'm now in the process of boxing it all up and putting it on my vario benzine. I'll also need a 3cell lipo with about 10000MAH for the modems.
I'll make a flying video as well this weekend.
Lemme know what you think and ask questions if you have any.
Sorry for the lenghty post and the ugly video but I just wanted to share.

http://www.youtube.com/watch?v=8eJgTgWBwQA

DarkHeli
08-07-2008, 07:49 PM
sweet! How much did the modems set you back?

zozie
08-07-2008, 09:25 PM
for all radio gear about $1600. which is not bad considering it won't glitch and for $20 I can add an extra 8 channels

SeaHawk
08-08-2008, 08:16 AM
for all radio gear about $1600. which is not bad considering it won't glitch and for $20 I can add an extra 8 channelspost a clip of it flying. How is this an advantage over conventional transmitter?

zozie
08-08-2008, 10:01 AM
Other than 40 mile range, GPS mapping, no interference and the ability to have 40 channels with as many mixes as you like, can't think of anything.....

dviry
08-08-2008, 11:13 AM
I've been thinking about the same but with a Wii-remote - surely that would be easier now, just a driver to add! ;)

Of course 20 miles range sounds neat, but would the battery really last that long? :roll:

How do you control the collective - like pitch (I am guessing throttle is fixed or governed?)

SeaHawk
08-08-2008, 11:43 AM
Other than 40 mile range, GPS mapping, no interference and the ability to have 40 channels with as many mixes as you like, can't think of anything.....you should anticipate some reluctance from the FCC & the FAA regarding their support of your mode of control methods.

zozie
08-08-2008, 01:37 PM
Collective is the up and down slider on my joystick, tail is rotating it. I think it could be done with a WII remote as it's bluetooth but I think it'd be hard with no resistance if you know what I mean :)

furyphoto
08-11-2008, 08:20 PM
Great, Now just add GPS position and altitude hold, and stabilization, and I'll buy one from you! ;)

Also, since you are from Canada, my guess is that the FCC, and the FAA do not apply!

ChasHeliCop
08-11-2008, 10:25 PM
Also, since you are from Canada, my guess is that the FCC, and the FAA do not apply!

That's exactly what I was thinking, FAA would knock us out of the sky. UMA

zozie
08-12-2008, 09:50 AM
I'm not sure if they would as the modem I'm using is for sale in the US as well without a radio license. FAA tho is a different story. I'm not sure if they'd care tho whether you fly from yout TX or your computer.....