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Posts posted by jonpet55

  1. Very tempting!

    The screen displays look dynamite!

    Still, alot of unanswered questions.

    There is no picture of the OSD and even the actual weight and dimensions are undecided.

    The specs put the autopilot and return to home on the same line, raising the question can it actually follow waypoints or is it just a failsafe feature.

    The specs show a vario function, would that be from gps altitude alone? Most are not accurate enough to do that.

    There seems to be an arificial horizon, how is that supposed to work without IR sensors or an IMU? In theory bank angle can be calculated knowing speed and turn radius but I've never seen it done for an artificial horizon.

    Will there be options for sensors, IMU, data logging, Google Earth mapping and waypoints?

    It does look promising, and the price is right.


    The dimensions of the board is 9x5cm - weight is still unknown.

    Vova says the board will have full waypoint capabilities before the end of july.

    The variometer is only based on GPS readings. A GPS is pretty accurate on relative vertical movement, but not absolute.

    As said, there is no AHI. Optional sensors has not been announced, and will most probably never be.

  2. eickst: I would have said the same as you a month ago. Sorry to say I don't have that opinion anymore. I ordered a pan/tilt kit for my TSII which I've been waiting for allmost 3.5 weeks. Still haven't got it, and vova doesn't respond. I guess it will be worse after the release of this OSD.

    Terry: The number of commercial OSD-solutions has exploded the last few years, so yes, I'll guess the prices will fall.

  3. Well, I was expecting someone would mention that. At first I'll say I wouldn't have done this with a bigger plane, and the only reason I did it was because I find the plane pretty harmless. It is a very slow and lightweight plane, but I can agree it was a little bit on the edge if I knew I was going to get these problems - which was not expected at all.

    My future plans is to make a rudder-home system, so this would probably not happen again. I will also fly in the opposite direction, which is over a forest.

  4. I have just finished my new ground station. I found out it was much better controlling the plane from my room due to multiple reasons:

    - I don't have to carry all my gear to the field

    - I can use monitors instead of googles - the sun shining into the monitor is

    no longer a problem

    - I can sit on my chair - much better comfort

    Enough talking, here is some pictures:



    For more information, look at http://skagmo.com/fpv.htm

    This is my latest video. This flight was really nerve-wrecking! ;)


    The TSII will be a much more stable platform with pan/tilt and a CPD4 for extra stabilisation.

    Hope you like it!

  5. Thanks headhunter23 :) I flew the plane today as well and it was easier this time, probably due to less wind, less nerves and a better pilot. The plane didn't fly as fast today. Just the right speed for me. Last time it was actually pretty windy (today it wasn't any wind at all), so thats the reason why I got the extra speed. I was pretty close on crashing today. The problem was that I flew the plane a little too long, and suddenly one of the ESC's cut off due to low battery voltage. I couldn't see that one of the propellers had stopped, so I didn't understand why the plane started to drift to one side. I gave full throttle to compensate for the lack of thrust, and came _very_ close to a tree. A moment later I realised what the problem was, cut of the throttle, throttled up again and landed. In other words still no damage... :)

  6. WOW! I just flew the TS2 for the first time, and it was insane! :D

    I'd never imagined it was so fast and responsive.

    Lucky for me the kids in the area had just left, so I was alone when I started flying. I threw it into the air with full throttle, and wasn't prepared for the speed at all. I also had way too much response, but didn't dare to look down on the DX7 for the D/R-switches. I tried to think where the switches was located (just switched to the DX7, so I'm not used to the radio yet) and steer the plane at the same time. After a few seconds I remembered, and enabled D/R on ailerons and elevator, giving 50% travel. It got easier to control, but still not what I would call easy. After getting a little more confident with the plane I flew it over a larger area with more altitude. I also discovered that about 15-20% throttle is enough for level flight, so I was applying much more throttle than needed. I tried to fly the plane low with little throttle, and then with full throttle and elevator. It flew vertical at incredible speed, becoming a little dot on the sky after a few seconds. I landed it perfectly some minutes later, using flaperons. When I applied full flaperons it stopped like a car. It was incredible to watch. I had to apply lots of elevator up to keep it level though, so I'll try to add some elevator to the flaperon-mixing.

    After landing I discovered 10-15 people were standing right behind me watching me flying, and I hadn't even noticed...

    I think I've got to fly the plane a few more times before adding FPV-gear, because this wasn't at all what I expected... Very fun to fly though, and the plane is still in perfect condition!

  7. I haven't visited the thread for a while, so sorry for my late reply.

    Philtyy; Thank you for the kind words! :)

    The software for the OSD and the other stuff is now more or less finished.

    In the video below I use a cheap 2.4GHz transmitter - not the one in the picture.

    Check out a video of the first OSD-test here.

    A picture of the completed FPV stuff:


  8. Thank you for the comments.

    Rking: The OSD is made by me, so it is not a commercial solution.

    Mr. RC-Cam: I have tested the 23cm TX with both the GPS and the AR7000. The TX is much more high quality than Lawnmate transmitters etc., so there is almost no harmonics. I was expecting the TX to block out the GPS though, but testing shows that the signal is just slightly reduced even when the transmitter is 2-3cm close. I guess I can thank the saw-filter on the GPS for that (EM-411 has a saw-filter right?). The AR7000 also performs very well close to the transmitter, but to be sure I bought a 36" extension cable for the remote receiver, so it is now located at the tail, while the 23cm TX antenna is on the nose. Almost 1m separation.

  9. A while ago I decided to build a TwinStar II for FPV use.

    The plane is not ready to fly yet, but I hope to get it ready within a week. Actually the only thing missing is 30cm silicon wire for the left motor (I made 5 out of 6 cables, and went out of wire). The paintjob is done with black and silver acrylic spray paint.

    It will be equipped with the following gear:

    - AR7000 2.4GHz diversity R/C receiver

    - 4 x Hitec HS-81

    - 2 x Turnigy 2213 20-turn brushless motor

    - 2 x TowerPro w25A ESC

    - 3A UBEC

    - 2 x Aluminium spinner

    - 2 x 9x6 APC propeller

    - 11.1V 4000mAh LiPo

    And the following FPV-equipment:

    - KX131 video camera

    - 1.3GHz (23cm) 1W video transmitter with a four radial GP-antenna

    - Totally custom OSD based on the BOB-4 video overlay board

    - EM-411 SiRFStar III GPS

    - TinyTrak 3

    - 3A 5V switch mode regulator

    As said, the OSD uses a BOB-4 module for video overlay. I originally controlled the BOB-4 with a PIC16F88, but the increasing amount of float variable calculations and other demanding operations forced me to upgrade to a PIC18F1320. More technical information about the OSD will come later.

    It is now fully working (not as seen in picure 16 on the OSD-page below).

    The TinyTrak 3 is used to transmit lat./lon. and altitude to the ground station to calculate azimuth and elevation angles for the receiver antenna. I will proceed the development of this system as soon as the basic FPV/OSD system runs satisfiable. The AX.25 decoding on the ground is done with a PIC16F88, and the trigonometrical calculations is done with a PIC18F1320.

    The plane so far:


    The FPV-stuff so far:


    More pictures:




  10. Thank you! Hehe, yes. I was expecting more problems than I actually got. The hour between LOS (video transmitter got out of range), and AOS (the cell phone was low enough to connect to a base-station), made me extremely nervous... :P The descent was calculated to take about half an hour, but because the ropes got messed up (you can see a rope hanging down on the side of EOS1, that was not supposed to happen), the release mechanism of the balloon had no effect, so EOS1 continued to gain altitude until the balloon exploded. Therefore I had to wait much longer for AOS. But, when the cell phone finally replied, everything was working perfectly. It was a few hundred feets over the ground, and when it finally landed, I noted the coordinates, and sent them to a friend of mine. He wrote them in as a waypoint on a traditional Garmin GPS. After driving for allmost two hours, he could hear (the siren) and see the payload straight out of the window of his car - it landed in the center of a field next to the road! It couldn't be easier!

    Edit: The glider idea has been on my mind many times. I was mostly thinking about making a UAV that could automatically land on the launch-point (as others have done before).

  11. Actually, I will not make the PIC PPM decoder myself. When I started to find a new solution for the RC transmittion, I found out that I was making too much job of everything. My main goal was to design the antenna rotator system and the OSD in the plane, and make a nice FPV-setup that I cound finish in a reasonable time. I didn't had to make every part of it myself. So not to reinvent the wheel, I started to search for someone else who had allready made what i needed: A simple PIC PPM decoder, but with failsafe. I found this one: http://homepages.paradise.net.nz/bhabbott/decoder.html. As you said I could also take the PPM demodulation circuit from a standard RC RX, but I actually don't have any microprocessor decoded receivers (just with simple shift registers), and it would be much less expensive to program one of my PIC's with this firmware, than buing a receiver and ripping it apart...

  12. Nice to hear your response about EOS1. The project amazed me when it comes to how far it is possible to reach with the same kind of radio equipment we use here (near 80km with Lawnmate RX & 600mW TX).

    The antenna tracking system is working really good so far. I have only tested azimuth though. The APRS data is sent through the audio channel of the video transmitter, decoded by a single PIC TNC, then az/el angles are calculated in another PIC. I am planning on building a simple rudder "return to home" autopilot too.

    The RC signals will most probably be transmitted on 433MHz. I will try to transmit the raw modulated PPM signal from the trainer port with a TM-D700, then receive it with a small Alinco handheld radio and decode it with a PIC PPM decoder. If this doesn't work well I will find another more complex solution.

  13. Sorry :unsure: I miss understood from the start, when I saw the set up you were planning I got the impression that cost was not important, my mistake :(

    But I agree if you are going to use a helical then diversity is not needed :)


    No prob Terry.

    By the way, the helix I found above comes from a page called yagi.pl. They have extremely cheap antennas.

    Helical antennas: 10$ to 19$




    Parabolic reflector: 8$


    Parabolic reflector with 2.4GHz antenna: 26$


    Yagi antenna: 23$


    To convert from zloty to U.S. dollars, go to google, and type: "xxx PLN in USD"

    Now I know where to buy all my antennas... :D

  14. Well, yes, with 3dB loss I will loose half the power, but there are so many other factors I have to consider. Price is a very important one. :rolleyes: Either one antenna with circular polarisation and one receiver, or two antennas with linear polarisation, two receivers and an Oracle...

    Instead of using lots of money on the polarisation diversity setup, I could just buy an even more directional antenna (17dB instead of 14dB).

    I am considering changing the transmitter antenna too. I'm thinking about an antenna similar to the one I used in EOS1 (search for it here). It's radiation pattern was allmost like a dome (or half a ball), and it had allmost equal components of vertical and horizontal polarisation. The groundplane spaced 1/4 lambda from the dipole made this behavior.

  15. I can see I expressed myself a little wrong. I meant traditional diversity setup to eliminate problems caused by multipathing. I think I have found a solution to eliminate the polarisation problems. I'll use a circular polarized antenna instead, then I will loose a constant 3dB instead of up to 24dB. Another problem is finding a high gain circular polarized antenna. I think I'll have to make myself a helix (a crossed yagi for 2.4GHz is just too much job)...

  16. Hartwig, your post allmost completely changed my mind... ;) The question is if I really want to pay 200$ extra to eliminate a few dropouts when landing. When I fly at high altitude (as I will do 95% of the time), the diversity makes no sense.

    Another important factor is that I will need to reconstruct the az/el rotor to hold two antennas.

    By the way I have just found out I will buy the HeadPlay video googles. Yes, they are expensive, but they are the only option because of my rather wide interpupillary distance, making the cheap video googles with 63mm IOD unuseable to me.

    So, the HeadPlay costs 500$, two lawmate receivers plus a 1000mW transmitter cost 215$, the Oracle diversity controller cost 150$ and the antennas cost 100$. That makes 965$ only for the AV-system excluding OSD and antenna-rotator... Way too much... ;)

    Today i have taken a few photos of the rotor so far, shifted the oscillator on my BOB4 from 75MHz to 74.25MHz (the soldering was easier than expected :) ), and got my last order from HobbyCity. These parts will be used in my TwinStar II.









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