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Gremlin Issue Help!

#1
Hello,

Recently I was able to get my Gremlin up and flying. Quad is super quiet and is very smooth. I thought I would be ready to FPV, but it turns out my camera is having issues sending signal to my goggles. I currently am using the Fatshark Teleporter V4s that were sold under Horizon Hobby. The module is built in so I cannot swap it for anything else. I'm wondering if there is a compatibility issue as the goggles seem to work with all my other FPV quads. (Inductrix FPV, Vortex 150, etc.) The camera on the Gremlin is powered up and I can cycle through the different channels by watching the red LED move along the board. I noticed if you long press the button it will move the blue LED which I assume is for different race bands. I have tried all sorts of combinations, but I cannot get video signal to the goggles. Can someone please advise? I've been itching to get this quad flying but I've hit roadblock after roadblock.

On a side note I wish the FT store would have offered the build option from the start. I think I could have saved myself a lot of headache. I guess the good news is I did learn to solder better overall. :)
 

PsyBorg

Wake up! Time to fly!
Mentor
#2
What you need to do is look on the manuals / papers that came with the camera and the goggles. They should have the usable channels and bands in a table. Then match the channels and bands to the same frequency on both. Be aware though in Real flight there are many outside factors so what looks like a good match on the bench may not be outside at range so find several common frequencies and make a list or take the tables with you so you can adapt to real time conditions.
 
#4
I have went over the manual for both. The camera is set to Fatshark bands and I have tried all channels with no success. On channel 1 I get a grey screen. As I progress through the channels the static becomes worse.
 
#6
Please Advise

Trying to see if anyone has any insight on what I might be doing wrong. I have checked everything to my knowledge. I'm starting to really get frustrated. I really want to get this quad flying.
 

PsyBorg

Wake up! Time to fly!
Mentor
#7
Tell me what camera / VTX you are using and I will cross reference the available channels and make sure they are compatible. (nearly 100% sure they are) as well as tell you what channels match up.

I know in the vtx and receivers I have several have the band order changed so it is not an matter of choosing bands by beeps. Like some are band 2 for the VTX and band 4 for the receiver to actually match.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#8
Sorry gotta ask...

Got the lens cap off the camera and is the battery for the goggles charged?

Sorry, but you just gotta ask... :)

Are you sure your antennas are the proper connectors (SMA or RP-SMA)?
 
#10
It sounds like your using the HYPERION MINI 600TVL 25mW CAMERA VTX Version 1, this is the camera option when you buy the gremlin build kit.
When I check the goggle your running it has mathcning frequencires on Band 1 (F) channels 1 to 7, but not 8 and that might be the black screen your getting is on channel 8. So the first band light (I think it's blue) and first channel light will be your channel 1 on your goggles.

The camera should be able to run off of 2.5V to 5V, and I believe if you wired it to UART2 (pins next to the one pin labeled TX2) I read that the uart2 5V leg has a built in LC filter so that should stop any interference.
Check the antenna on the camera to make sure it didn't break, or the solder points are not shorted out.

I'm going by the original gremlin kit build.
Make sure UART2 is not using anything in betaflight unless you are using UART2 TX for telemetry.
You should be using the spectrum serial receiver on UART3 if you bought the full kit and original recomended parts.
This camera can't be wired directly to the power on the PDB, it need a regulated voltage.
Maybe take a multimeter and check to make sure it's giving 5V from the UART power pins.

I guess you should also make sure the brightness and contrast are not turned all the way down on your goggles.
Sometimes the video receiver switch gets stuck in the middle, flip it on and off a couple times.
Of course check to make sure you battery is above 3.3V, the goggle will still power on at 3V but the LCD's won't display, or maybe the lcd's will display but the receiver module isn't working all the way. If you have a bench power supply you can test them with a D.C. Barrel connector, I think the middle ismpossotive but I would confirm with your battery first. Set the power supply to 3.7V.
And finally if you know your in the correct channels, have power from the board to the camera at 5V and good power to the googles you could always hook up the AV out cable and plug the yellow RCA jack into a TV or living room receiver and see if you get a picture.
I hope this helps, let us know how it turns out.
Scott
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