Pot-Roast of Beginner's Questions

Discussion in 'CineStar FAQ - Tips and Tricks' started by Zach Beggs, Jun 2, 2013.

  1. Zach Beggs

    Zach Beggs Member

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    I'm wiring my OSD setup, any help would be appreciated.

    Overall my biggest question is: do I use power grounds for video grounds? That's a lot of Y-cabling...

    So far, I'm pulling power from my PDB and sending it to a 12v DC/DC regulator. The now regulated 12v +/- get split and go to a iftron camera and to the transmitter. From there, the camera's ground lead is split again and sent with the video to the OSD for ground.

    Again, splitting the ground on the transmitter, the video out from the OSD, incoming video now has a ground.

    Is this correct?

    Thanks!
    Zach
     
  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Yup. Everything needs to be on a common ground otherwise the positive voltage has no "reference." It won't even look like a +ve voltage.... :)

    I just noticed -- you're using a 12v DC/DC regulator? What input voltage are you providing and what is the designation of the regulator? (As in is a Traco xxxx)?

    Andy.
     
  3. Zach Beggs

    Zach Beggs Member

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    It's a Traco from QC. The 12v one.

    The Traco is soldered onto the MK PDB. Then the +/- out of the Traco are split between the camera, transmitter, and the transmitter's ground for video.
     
  4. Zach Beggs

    Zach Beggs Member

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    So input volts are 17-14
     
  5. Shaun Stanton

    Shaun Stanton Active Member

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    You might consider powering everything with a separate 3S battery. This negates having to tap power from the main A/C battery. This will keep your video camera and TX running if you end up loosing power on the main battery, as well as preventing video blackouts if you inadvertently over power the system.

    Shaun
     
  6. Zach Beggs

    Zach Beggs Member

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    will a 1200 QC work? Should I still use the 12v reg?
     
  7. Gary Haynes

    Gary Haynes Administrator
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    See drawing below.

    The Battery to Mondo/Iftron and Mondo/Iftron to Cam Switch are the supplied 6 pin cable from Iftron.
    I use Dean's for power connectors.

    Zippy 3s 2500 battery.

    The camera switch is optional.

    If you leave out the camer switch then take the yellow longer 3 pin cable from the Iftron. One end connects to the Iftron.

    About half way down I cut the cable. The video and ground from the Iftron side go into two ports of a 1x4 Berg connector. You can use the cable supplied with the SmartOSD but I found that working with the micro wires a pain. Bought some 1x4 BERG's from Hansen Hobbies. Since I already was making servo connectors I had the other parts.

    On the other piece of the cable that connects to the camera I put BERG connectors on the ground/video wires and put them into the other two ports of the BERG.

    Solder the positive wires together.

    Put the BERG connectors into the 1x4 connector so that the output from the SmartOSD is going to the Iftron and the input side is going to the Camera.

    Screen Shot 2013-06-22 at 6.29.26 PM.png .
    Pay very close attention to the Video/Ground/Power. Easy to get confused since the wire after the Iftron is all one color.

    Shaun you have something similar?
     
  8. Shaun Stanton

    Shaun Stanton Active Member

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    1200 will work perfectly. I get about an hour with a 1000 with my setup. As long as it is a 3s, no VR required.
     
  9. Zach Beggs

    Zach Beggs Member

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    All is well and I have a video feed and a OSD on my monitor :)

    However, the monitor looks like it's scaling to fit... I'm loosing the bottom half of my screen. I can tell because I can only see half of the OSD data (the upper-top half).

    I confirmed that the layout was good in the OSD software.

    I think it's the monitor -- but I've tried changing settings and I have had no luck! Any ideas?
     
  10. Shaun Stanton

    Shaun Stanton Active Member

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    You have to change the ratios of the screen through the software. It will not look correct on the page on the OSD manager. What you see on the OSD manager is not exactly how it will be projected on the screen. Here are my settings. Notice some of the stuff overlaps on the main screen but will be correct on the actual display. This is because this system does not know resolution between PAL and NTSC.

    OSDexample.jpg
     
  11. Zach Beggs

    Zach Beggs Member

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    Im considering using the flight lipo for the OSD/FPV. The benefits of a independent battery sound great -- I'm just not sure about adding the extra weight you know? I feel like the 5D is already putting me really high on the scale.

    I'm running stock MK stack -- 450mm, stock props, etc. with a 3-axis and a 5D/24mm prime on a 1200 QC battery.

    Also I am not running parallel (well see in the future), but just a single 8000mAh
     
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    The issue of connecting "not essential to flight" equipment to the flight battery is one of reliability, I think, Zach. The more stuff you have hanging off the flight battery, the higher the risk that if something fails, then it might short out or drag down to the flight battery voltage and cause Bad Things to happen. Also, if you can drive your video of a separate battery, then you reduce the amount electrical noise that may manifest on the video signal, so you'll get better quality video.

    But you're right to be pondering the weight/reliability tradeoff, IMO.

    Andy.
     
  13. Shaun Stanton

    Shaun Stanton Active Member

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    You are right every ounce added is more thrust required. I find the small 3S 1000-1200 type batteries to be somewhat negligible in weight added in the big scheme. Flying with your camera setup you should not have any issues with the small battery. I have flown with some heavier glass on the MKII and the FS the copter handled it fine. It was a little strained when I flew it with the FS-100 and a 18-200 glass. Even at that point IMO the small battery would not made that much of a difference.

    I fly with a host of different 3S batteries. If I need to shave off a little weight I will use one of my 500mAh batteries, just swapping them out more often. I have a Hyperion battery tester that I use to check the levels on the small batteries each time I land. You can put these batteries on the OSD and monitor them as well with some extra soldering. I do not do this because I find that since it is not a critical system component it just makes my display more busy then it already is. A good technique to save battery life is unplug them each time you land unless you are doing an immediate main batt swap and takeoff.
     
  14. Zach Beggs

    Zach Beggs Member

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    Dang! FS100 & the 18-200 glass...

    I did some test flights with the new OSD and the camera. First thing I quickly learned -- altitude optically minimizes dramatic movements or unwanted velocity via FPV. Switching to LOS, you're moving quite quickly -- but the altitude in the FPV looks very subtle.

    ----

    I do have a new problem brewing in the pot-roast though!

    Here's my setup -- I'm planning on moving the 1.2 where the xbee is and ditching the xbee all together, I don't use it very much.

    1. I am getting a dramatic suppression on my Tx/Rx signal strength. I could be near the copter (same testing location as before) and 100 feet out I will drop to 50% signal strength with my Graupner MX-20 & GR-16. About 400 feet away I was dipping to 20% signal strength in a park.

    2. Also, I am getting new errors on my GPX files:

    Magnet Field: 103 117 126 % <- check!
    Magnet Inclination: 52 58 68 deg

    Errors / warnings:
    Compass is disturbed by magnetic fields!


    I've flown at this location several times before, no errors. I'm planning on getting a rabbit for the GR, but I've been flying without one for a while and it's been fine (75+ signal strength).
    Side Note: The 1200 QC battery sits on top, where the xbee is.

    [​IMG]

    [​IMG]

    [​IMG]
     
  15. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    The whip antennae should be vertical -- the power radiates out from the tip of the antenna is a doughnut ring that's at 90 degrees to the long axis of the antenna. Right now, you're blasting most of the RF power into the ground or up towards Alpha Centauri. :)

    You'll get even better performance if you use Bluebeam cloverleaf antenna (www.dpcav.com).

    You need to recalibrate the compass each time you fly at a new location (more than say, half a mile away). You'll see the warning you're getting if the compass needs to be recalibrated.

    Hope this helps.
    Andy.
     
  16. Gary Haynes

    Gary Haynes Administrator
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    I would move the video TX (at least I think that is what you have next to the GR16 much further away from the GR16. Out on one of the booms if you can. Also seperate the two GR16 wires so that they are more at a 90 degree angle. I did that with a set of stir sticks in a small frame before getting the rabbit ear thingy.

    If yo check the mag field on the MX-20 prior to take off sometimes moving the copter a few feet will make a difference.

    Lastly I have begun unplugging and removing the Xbee tx/rx. I don't use it in flight unless testing. Eliminate the weight and slight power draw and the mag readings went up.
     
  17. Shaun Stanton

    Shaun Stanton Active Member

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    That's strange. You might move the lawmate as you suggest. Just curious, are you able to use your Xbee through the 2nd UART on the OSD? I have never been able to get mine to work through the OSD. It seems that it is hit or miss from everyone on the forum. I can get the USB to talk to MK through the OSD but not the stupid radio. So I ditched it along time ago, I only use it for test flights but I have to disconnect the OSD. I have one the first iterations of the new OSD board with the 10 pin UART, so my thought is that it may have some flaws.

    Anyway, some thoughts are. That yeah the Xbee with the Lawmate may be causing some interference. I never had issues with the 1.3, although I use it for my gimbal. I have a clunky 900Mhz for the pilot camera.

    Another note. I noticed that some of the wires on the OSD are not braded. You might do that to mitigate some EF interference on the magnet compass. I have my stuff sheathed in a mesh shield with a clear shrink for the cable as it gets routed under the FC and PDB, to prevent the braid from zapping stuff.

    View attachment 2243 photo (20).JPG photo (19).JPG

    I have a gimbal nose camera setup on a cheap board camera and gimbal from hobby king. I use the MK gimbal compensation for it so I can keep the camera angle the same angle as I am tilting the copter.
     
  18. Zach Beggs

    Zach Beggs Member

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    Hey Shaun, I cleaned up the cabling, it's much cleaner now! The last cabling was redundant as well, as all the wiring went through a 12v dc/dc which was unnecessary when using a 3C.

    Also, I made the cable longer and was wondering if I should put it at the top of my copter's boom marker. Or should I reserve that spot for the GR-16?

    [​IMG]

    [​IMG]

    [​IMG]
     
  19. Shaun Stanton

    Shaun Stanton Active Member

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    It looks like a nice clean setup. That's a good idea to shove the TX on the tail fin. You should be able to mitigate a lot of the EM. One note on the compass calibration. I do not calibrate every time I change locations. This might be a practice that people who live more north may have to do because the radius of the earth is smaller as you go closer to the poles, so the earth natural geomagnetic field declination changes are larger. I am not trying to say that is a bad practice though. I have not seen any issues with my rig in the local area, other than when I fly in magnetic areas such as an abandoned rail yard, an a film studio that I did some B footage for which will happen regardless. In fact I had a flawless compass 85 miles away from where I originally calibrated it on a shoot. What I do is when doing the calibration I turn on as much electric equipment as possible short of a camera.

    I turn on the gimbal with radians powered, the gimbal video tx, the nose camera tx are all on. This way the compass is normalized to most of the electric fields on the aircraft. I find this practice works well. You should not see too many issues with your rig. Big picture your fixes should work. As for the GR-16 or the TX being on the fin, it probably makes no difference which one you use. I would probably leave the GR-16 on the HUB, it should work fine
     
  20. Gary Haynes

    Gary Haynes Administrator
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    Agree with Shawn on calibration. Mid latitude (40's) 1 degree east or west is something like 69 miles. The MK compass system can't be that accurate, the way it swings around. So unless I am going a long way I haven't been doing it. And it wouldn't make much difference in an area of iron would it?

    wiki info
    Each degree of latitude is approximately 69 miles (111 kilometers) apart. The range varies (due to the earth's slightly ellipsoid shape) from 68.703 miles (110.567 km) at the equator to 69.407 (111.699 km) at the poles. This is convenient because each minute (1/60th of a degree) is approximately one mile.
     

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