Posts: 321 Threads: 51 Likes Received: 123 in 88 posts Likes Given: 164 Joined: Nov 2017 Reputation: 6 So I have a LS-210 build. It has an Omnibus F3 (OSD), a Eachine 1000TVL CCD FPV camera, some 20a escs with 2205 motors, an Eachine VTX 02 200mw VTx, 1800 4s lipo, a Flysky Rx, and a Matek PDB. Overall, it is a pretty solid build and it flies very well with Betaflight. I have a very tragic problem though. When I am just at idle and disarmed, my integrated OSD and FPV work great, with everything displaying correctly, but as soon as I throttle up to ~>10%, there are immediate lines in the video feed. It gets worse as I increase the throttle, and by the time I'm at ~50%, it is totally blacked out with the whole screen showing static. I have checked and double checked all wire connections (/w multimeter of course), and everything looks and works fine except for the FPV! I think that it is a VTx problem, but if it is, I have no idea how to fix it. The FPV camera is a 5-20V camera and is powered directly from my 4s lipo (14.8-16.8V through the Omnibus OSD headers), and the 200mw VTx (input 3.7-5.5V) is powered from the 5V rail also on my Omnibus F3. It would be great if someone could help me out here! I have gone through three FPV transmitters hoping to solve this problem, but the same problem keeps on coming! Thanks! ![[-]](https://intofpv.com/images/collapse.png) • Posts: 12,099 Threads: 125 Likes Received: 3,739 in 2,836 posts Likes Given: 99 Joined: Feb 2017 Reputation: 388 13-Dec-2017, 07:46 AM (This post was last modified: 13-Dec-2017, 07:47 AM by voodoo614.) I would power the camera off the VTX 5V Out. Put a low ESR 1000uF capacitor on the lipo lead. That should clean up your ESC noise and reduce your video distortion. Posts: 1,504 Threads: 83 Likes Received: 944 in 654 posts Likes Given: 2,142 Joined: Sep 2016 Reputation: 24 13-Dec-2017, 11:37 AM (This post was last modified: 13-Dec-2017, 11:40 AM by Tom BD Bad.) (13-Dec-2017, 07:46 AM)voodoo614 Wrote: Put a low ESR 1000uF capacitor on the lipo lead. Or on the power wire of each of your ESC's. Slightly lighter and lower uF (low ESR) caps ie. 470uF 25v should be OK for individual ESC's. You may also consider an LC Filter attached to the power leads of the camera and VTX. Windless fields and smokeless builds • Posts: 5,315 Threads: 672 Likes Received: 3,155 in 1,743 posts Likes Given: 2,030 Joined: Jan 2016 Reputation: 139 My suggestion: 1. Power both of your VTX and camera from the 5V on your FC, make sure they share the same ground pin on the FC 2. as suggested by voodoo, add an capacitor on the power input pads similar to this: ![[Image: P0ZODrml.jpg]](https://i.imgur.com/P0ZODrml.jpg) • Posts: 321 Threads: 51 Likes Received: 123 in 88 posts Likes Given: 164 Joined: Nov 2017 Reputation: 6 (13-Dec-2017, 07:46 AM)voodoo614 Wrote: I would power the camera off the VTX 5V Out. Put a low ESR 1000uF capacitor on the lipo lead. That should clean up your ESC noise and reduce your video distortion. When I power the camera from 5v, it intermittently drops out and my screen turns grey muck like as if I disconnected the camera altogether. The camera needed more power, so I hooked it up directly to 4s, and it worked fine, but the VTx problem was still there. I might try the low ESR cap route, btu is there any difference between that and an lc filter? • Posts: 321 Threads: 51 Likes Received: 123 in 88 posts Likes Given: 164 Joined: Nov 2017 Reputation: 6 (13-Dec-2017, 03:25 PM)Oscar Wrote: My suggestion:
1. Power both of your VTX and camera from the 5V on your FC, make sure they share the same ground pin on the FC
2. as suggested by voodoo, add an capacitor on the power input pads similar to this:
Quick question Oscar; why do both gnds for the VTx and cam need to be connected? Just curious would it still work if I kept them separate? • Posts: 1,504 Threads: 83 Likes Received: 944 in 654 posts Likes Given: 2,142 Joined: Sep 2016 Reputation: 24 (13-Dec-2017, 03:59 PM)raspberrypi33 Wrote: Quick question Oscar; why do both gnds for the VTx and cam need to be connected? Just curious would it still work if I kept them separate? I guess it 's the same reason for ESC signal ground? If you think of 'Gnd' as the actual ground, interference is like riding a bike over rocky territory, the reference of where the ground is will differ from the front wheel to the back... Considering signal values are calculated using a differential, if you connect the VTX to a common Gnd, and the camera to 5v Gnd, continuing the analogy, it is like collecting data from different wheels, they will not have the same idea of where the 'ground' actually is. Connecting to the same Gnd allows the camera and VTX to use the same 'wheel' as a reference to accurately calculate the differential of the signal. Not sure that actually makes any sense, but, (at this time of year anyway) it's the thought that counts! Windless fields and smokeless builds • Posts: 321 Threads: 51 Likes Received: 123 in 88 posts Likes Given: 164 Joined: Nov 2017 Reputation: 6 (13-Dec-2017, 06:05 PM)Tom BD Bad Wrote: I guess it 's the same reason for ESC signal ground?
If you think of 'Gnd' as the actual ground, interference is like riding a bike over rocky territory, the reference of where the ground is will differ from the front wheel to the back... Considering signal values are calculated using a differential, if you connect the VTX to a common Gnd, and the camera to 5v Gnd, continuing the analogy, it is like collecting data from different wheels, they will not have the same idea of where the 'ground' actually is. Connecting to the same Gnd allows the camera and VTX to use the same 'wheel' as a reference to accurately calculate the differential of the signal.
Not sure that actually makes any sense, but, (at this time of year anyway) it's the thought that counts! Thanks! Posts: 321 Threads: 51 Likes Received: 123 in 88 posts Likes Given: 164 Joined: Nov 2017 Reputation: 6 I half solved my problem finally! After poking around my build for a few hours last night, I tried using the FPV without the OSD, and my problem was solved...for now. I haven't tried actually flying it, but I suspect that something is up with my Omnibus F3's OSD. Its fine though, because the OSD only helped with my battery voltage and timer, which I can get from my Flysky's telemetry. Posts: 1,504 Threads: 83 Likes Received: 944 in 654 posts Likes Given: 2,142 Joined: Sep 2016 Reputation: 24  happy flying! Windless fields and smokeless builds • Posts: 12,099 Threads: 125 Likes Received: 3,739 in 2,836 posts Likes Given: 99 Joined: Feb 2017 Reputation: 388 (13-Dec-2017, 03:59 PM)raspberrypi33 Wrote: Quick question Oscar; why do both gnds for the VTx and cam need to be connected? Just curious would it still work if I kept them separate? Here is a pretty good explaination https://www.rcgroups.com/forums/showthre...-are-equal • |
