Debugging FPV setup

[asnelt]

Hi,

I'm trying to build an FPV setup similar to the one of Fred:
viewtopic.php?t=1473
I bought the same 1g PAL camera and Altitude RC transmitter and currently power them from an external 1S battery (the Hubsan 380mAh) not attached to the Crazyflie:

On the receiver side, I am using a Mini 5.8Ghz FPV Receiver:
http://www.unmannedtechshop.co.uk/mini- ... 2-channel/
I connected this receiver to an EasyCAP USB Video Capture Adapter with the UTV007 chipset:

With this setup, I do get a video stream, but a really crappy one. Here is an example image from the stream:

There is a big gray stripe. The stripe is always present but not stationary when I move the camera. The colored areas show that the camera is working at least partially. For instance, I can see a little of my finger when I move it in front of the lens, but it's distorted.

The setup is a bit hard to debug, because all components are untested. So the problem could be anywhere between the camera and the EasyCAP. I tried different channels. For the transmitter antenna, I tried the one that comes with the Altitude RC and also the Cloverleaf one that can be seen in the picture. Same result for both.

I think the problem is not on the software side of the receiver, since I tried both VLC on GNU/Linux and EasyCAP viewer on Android with all possible settings and got the same video stream on both.

Can anyone here tell right away in which part such a problem most likely originates?

Cheers,
Arno

[derf]

Hi Arno,

I'd recommend to try to isolate the problem first.

• Did you try to use the EasyCAP with some other video input to make sure that it works?
• What does the screen show if you just disconnect the camera? (should be noise without any distortions)
• Maybe you can also try to hook up the camera directly to your EasyCap? (Be careful!)
• Do you have a friend or a friendly RC shop that would allow you to test your setup with a different receiver (e.g. Fatshark googles, FPV monitor)?

Hope that helps,

Fred

[asnelt]

Hi Fred,

Thanks a lot for your recommendations! The FPV setup works fine with Fatshark goggles, so the error is definitely on the receiver side. It must be the EasyCAP or the mini FPV receiver. I didn't have an opportunity yet to try the EasyCAP with other analog input and I could not hook up the camera directly to the EasyCAP, so I cannot tell yet which of the two it is. When I disconnect the camera, the screen indeed shows only noise without any distortions.

I will post a couple of pictures of the final setup as soon as I have everything nicely assembled.

Cheers,

Arno

[asnelt]

To conclude this, it was the mini FPV receiver being faulty. The EasyCAP works fine when getting input from the Fatshark goggles.

In the end, I changed my FPV setup quite a bit:

I still use the 1g PAL camera, but for the transmitter I switched to the Tx5810-100 which is much lighter and also has adjustable output power. The camera and transmitter are now powered from the main battery. For greater capacity, I replaced the stock battery with a Turnigy Nano-Tech 300 mAh (invert the connector, if you use the same!). I put a Pololu 5V Step-Up Step-Down Voltage Regulator in between to deal with the motor interference and hot glued everything onto the battery holder:

I put more glue than I had to to make it more crash resistant. I crashed a couple of times and so far it still works nicely.

Even with the voltage regulator, there is still a bit of noise in the image, but it is very well flyable in all situations:
https://www.youtube.com/watch?v=6ArYcENJ50k
When the flight is steady, there is very little noise.

As an additional small on-the-go FPV receiver, I chose the LaserBGC Android RX which acts as a UVC-compliant USB camera. The setup works fine on Android phones and tablets. I will see if I can modify the Crazyflie Android Client to have the camera image directly in the Crazyflie app. This would unify controller and FPV receiver into a single device.

Arno

[tobias]

Very nice build!

[theseankelly]

Hey Asnelt -- this build looks awesome.

How are you powering it? I'm guessing you're not tapping right in to the battery poles since the whole thing looks to be detachable? I'm guessing then you're running the 3.0v output from the deck pin into the polou, and that the Tx and camera actually work fine at 3.3V despite the spec sheet claiming a min of 3.5v?

[asnelt]

Hi,

Sorry for the late reply. Yes, the whole thing is detachable. I am connecting the Pololu to the VCOM (unregulated power) on pin 9 right hand side (second last pin on the right when you look into the direction of the Crazyflie) and to ground on pin 10 left hand side of the battery holder. I then power both the VTX and the camera from the Pololu. I think the regulated VCC would not suffice for powering both the VTX and the camera. It is still going strong and I am very happy with this setup.

Arno