Some VTX advice pleaseeeee

[whoelseisbored (LiamHowe89)]

Hi guys just got a couple of quick questions from a first time dabble into the FPV world...

Firstly here's the gear...
VTX: Eachine TX805
Cam: Foxeer Falkor 2 Mini
FC: Omnibus F4

...and my wiring diagram...
https://i.imgur.com/07jR8lb.png

1. I know VTXs get hot especially if plugged in on the bench... but how hot is too hot and how do I check?

2. When it's all plugged in I can literally see my VBAT telemetry number dropping through the floor! That's without any motors going! This surely can't be normal? Is there anything in my wiring that may be causing this?

3. The Falkor 2 has a purple cable coming from the "VSEN" port. What the heck is it and do I need it?

Hopefully they're nice and obvious answers to someone with some experience!

Cheers! 

[ched]

Hi guys just got a couple of quick questions from a first time dabble into the FPV world...

Firstly here's the gear...
VTX: Eachine TX805
Cam: Foxeer Falkor 2 Mini
FC: Omnibus F4

...and my wiring diagram...
https://i.imgur.com/07jR8lb.png

1. I know VTXs get hot especially if plugged in on the bench... but how hot is too hot and how do I check?

2. When it's all plugged in I can literally see my VBAT telemetry number dropping through the floor! That's without any motors going! This surely can't be normal? Is there anything in my wiring that may be causing this?

3. The Falkor 2 has a purple cable coming from the "VSEN" port. What the heck is it and do I need it?

Hopefully they're nice and obvious answers to someone with some experience!

Cheers! 

!. vtx will get hot possibly too hot to touch!! The heat is dependant on power so higher power higher temp. There may be a setting in BF to run at a lower power mode (pit mode) until you arm. It might be worth checking that out! Normally a vtx gets a bit of air flow from props when flying so temp isn't too much of an issue unless the air can't get to it. On the bench is not a great time for air flow so don't run on high power!! Use Pit mode if possible, better still disconnect if poss while on bench.

2. I am surprised that vbat is dropping that much. At 200mW it's only supposed to be pulling 200mA. Compare that to your lipo and it should run the vtx on it's own for about 6 hrs?? Your connection diagram looks ok. You have attached an antenna to it haven't you?

3. The VSen wire is normally for connecting to the lipo to Sense the Voltage and display it on your goggles via the cameras built in OSD. With FC that have OSD the camera OSD and VSen wire is not normally needed, you might need to turn camera OSD off in it's menu to stop having 2 OSDs!

Hope that helps?

[whoelseisbored (LiamHowe89)]

!. vtx will get hot possibly too hot to touch!! The heat is dependant on power so higher power higher temp. There may be a setting in BF to run at a lower power mode (pit mode) until you arm. It might be worth checking that out! Normally a vtx gets a bit of air flow from props when flying so temp isn't too much of an issue unless the air can't get to it. On the bench is not a great time for air flow so don't run on high power!! Use Pit mode if possible, better still disconnect if poss while on bench.

2. I am surprised that vbat is dropping that much. At 200mW it's only supposed to be pulling 200mA. Compare that to your lipo and it should run the vtx on it's own for about 6 hrs?? Your connection diagram looks ok. You have attached an antenna to it haven't you?

3. The VSen wire is normally for connecting to the lipo to Sense the Voltage and display it on your goggles via the cameras built in OSD. With FC that have OSD the camera OSD and VSen wire is not normally needed, you might need to turn camera OSD off in it's menu to stop having 2 OSDs!

Hope that helps?

1. Yeh did seem that way. I've just been tweaking it and set the output to 25mW and the temp stays a lot lower. Got SmartAudio working as well so can change it in the field if needs be. What would be the normal way to enter pitmode? I'm assuming it's holding the button while powering or something? The destructions that came with the VTX mention how to get out of it but not how to get into it. 

2. I figured that wasn't quite right but now I'm not convinced something is right with the telemetry because my VFAS sensor isn't returning anything. Other sensors from the FC seem to be ok which makes it even more confusing. Yep got my Lollipop attached haha.
Update: Ok it's not telemetry because when plugged in on the bench Betaflight Configurator is no longer showing a voltage. Any ideas why this might be? It was working before and I was able to see it on the OSD etc.

3. Ok that makes sense. Display seems to be ok, can only see the Betaflight OSD 

Thanks a bunch as always @ched!

[badger1]

1. you can set a switch to "pit mode" in the BF modes section, like to set up arming, angle/rate, etc.  alternatively you can probably do it through the usual BF on-screen menu for Smart Audio stuff.

2. maybe because of it having been dunked & the voltage sensor on the FC got fried?

[whoelseisbored (LiamHowe89)]

1. you can set a switch to "pit mode" in the BF modes section, like to set up arming, angle/rate, etc.  alternatively you can probably do it through the usual BF on-screen menu for Smart Audio stuff.

2. maybe because of it having been dunked & the voltage sensor on the FC got fried?

1. Cheers, will take a look at that.

2. How do you mean dunked? If that is the case is there much I can do? 

[badger1]

2. How do you mean dunked? If that is the case is there much I can do? 

oops, sorry, confused you with relativenewbyseb whose quad fell in the sea   

I'm not sure what FC/PDB/etc. you have - is the FC getting VFAS/VBatt to be able to measure it?  check a VBatt pin on the board with a multimeter.

[whoelseisbored (LiamHowe89)]

oops, sorry, confused you with relativenewbyseb whose quad fell in the sea   

I'm not sure what FC/PDB/etc. you have - is the FC getting VFAS/VBatt to be able to measure it?  check a VBatt pin on the board with a multimeter.

Haha makes more sense! Thought it was some term I hadn't heard of 

Right just checked the output of the VBAT pin and I'm getting 16.42v which is the same as it is at the battery physical connections.

The FC is a Omnibus F4 AIO

[whoelseisbored (LiamHowe89)]

So I've fixed it but no idea how. I did run set battery_meter in the CLI and it said none and default was ADC. Set it to that in the Power & Battery tab and it seems to work now. I had already done that a few times so no idea why it worked!

[relativenewbyseb]

Sadly yes dunking is not a technical term [emoji20] oh well live and learn [emoji23]

Sent from my VOG-L09 using Tapatalk

[whoelseisbored (LiamHowe89)]

Sucks that does! 

What happened? Electronics failure or misjudge your ground (water) height 

[relativenewbyseb]

Sucks that does! 

What happened? Electronics failure or misjudge your ground (water) height 

Flying slightly too far behind a rather thick bit of cliff sadly, tx signal gone and the last I saw in the goggles was 'disarmed'
But once I sort my own vtx setup queries I'll be back in the air [emoji3]

Sent from my VOG-L09 using Tapatalk

[ched]

Liam if you are still having issues I would be tempted to reflash the same version of BetaFlight and then set up again. Did you make a backup 'dump' in the cli and save it when it was flying correctly? If so then open the backup with notepad or some other text reader. Check the version of BetaFlight and the target, you then know the info to re-flash with the correct target and version. When it's fashed copy the 'dump' into the cli hit return then type save and return. You should be good again.
PS any changes made in the cli will only be stored once you type save then press return!!