Originally Posted by Ceros007

Hey darkstar, were are you from? What university?

Technical University Braunschweig, but already working at the German Aerospace Center in Braunschweig. Institute of Flight Guidance, that's why I need to make an autopilot for the copter...

Darkstar

Wow nice. I'm from École des technologie supérieure (Engineering University), Montréal, Québec, Canada. It's my first year. Aww I wish I could help you! It's such a nice project.

Did you ever try to read the joystick under linux?

We need to access the joystick, fill the bytes, calc the checksum and send it via IR. I think I will use the USB2Serial with FTDI chip from here (Just ordered a USB2Serial Cable with FTDI chipset). I especially like the "bitbang" mode: sending '1's and '0's with 72kHz to emulate the 38kHz carrier is very visual! So generating the packages seems to be not too complicated, but I never tried to use the joystick interface.

Darkstar.

No. I've never had a chance to actually work with something else than code... But I love electronics stuff.

Do you think it will be hard to do it with Radio Frequency Helis instead of InfraRed?

Probably yes, as it involves far more electronics: for IR you only need an IR diode (or three...). Als the protocol is quite different. I only started with this analysis, because it's so easy so to produce IR signals.

Darkstar.

Joystick and USB2Serial adapter are on the way. Now I only need some IR transmitter diodes, transistors and so on before I can program my own little remote. I keep you up-to-date.

Darkstar.

Wish I could talk technical like you guys...would SERIOUSLY impress the ladies in my local pub My father's hobby in his younger days was valve radios - he built hundreds of them. I can still see those valves glowing now, and my dad bending sheet aluminium to make the radio chassis. How things have changed.

Originally Posted by Redbaron25

Wish I could talk technical like you guys...would SERIOUSLY impress the ladies in my local pub .

Lol

With the help of a colleague and the guy who implemented the usb2serial driver into lirc I started the Joy2IR software. I expect the USB2Serial cable to arrive during the next days so I could start to send some commands to the heli and see if anything arrives.

Darkstar

PS: Syma comes next

If you can produce the IR codes from the computer, does that mean you could write a program to send out codes to fly the heli automatically in a preset sequence, eg take off, hover, fly a circuit and land?

Seen this done with model train layouts - fascinating to watch everything working on it's own.

Originally Posted by Redbaron25

If you can produce the IR codes from the computer, does that mean you could write a program to send out codes to fly the heli automatically in a preset sequence, eg take off, hover, fly a circuit and land?

Seen this done with model train layouts - fascinating to watch everything working on it's own.

Of course, why not? You could eventually put a wirelesscam on the heli an d fly it via your computer...
And if you want more, you can program an AI that can fly the heli.

That's the real meaning of "Impossible is not a word", I love computer science! ahaha

suddenly complex. If the heli 'dead reckons' it's position, it won't be for long.

You'd need some sort of position datum to work from.

too heady for me.
I'm happy to get a battery charged.

Hm, wouldn't it be easier to hook a joystick to a IR controller, without the PC in the loop?

Originally Posted by Redbaron25

If you can produce the IR codes from the computer, does that mean you could write a program to send out codes to fly the heli automatically in a preset sequence, eg take off, hover, fly a circuit and land?

Not impossible, but not easy. The problem is that a helicopter need to be controlled in a closed loop: To hover for example you need to know the altitude: Decreasing altitude -> more throttle, increasing altitude -> less throttle => closed loop. So we need some sensors (external or internal) to measure the position of the helicopter and then it would be possible.

Originally Posted by killbucket

Hm, wouldn't it be easier to hook a joystick to a IR controller, without the PC in the loop?

Maybe, but where is the fun in that??? And then you would need a analog joystick and make shure that the range of the variable resistors would match and so on. And in the end you would just control the heli with the joystick. Controlling the heli with a joystick from the PC is just the BEGINNING.

Darkstar.

The new joystick arrived today: shiny Microsoft Sidewinder Forcefeedback 2 to get some feedback in case of crash...
Software prototype is ready, now I need the USB2Serial adapter to hook up my scop to see if its working.

Darkstar.

Update of the timings (also for own documentation):

carrier frequency: 38.17kHz

(all timings in µs)
constant length, package-to-package 154819
header: 3699 pulse, 1004 space
zero: 814 pulse, 242 space (=1056, ratio ~ 2/3 to 1/3)
one: 398 pulse, 658 space (=1056, ratio ~ 1/3 to 2/3)
end: 387 pulse, 115937 space
length of data: 32 bits

byte,bit explanation
1,1 fix (always zero)
1,2...8 throttle
2,1...4 rudder
2,5...8 elevator
3,1 1=left rudder, 0=right rudder
3,2 1=nose up, 0=nose down
3,3 1=trim left, 0=trim right
3,4...8 trim
4,1...2 channel: 11=A, 10=B, 01=C
4,3...8 checksum

As soon as the USB2Serial is here I will send some commands to the helicopter to see if its working.

Darkstar.