Hello, Iam new in raspberry and open hd. trying to understand how to use camera switching. Is it working only with USB cameras and main raspberry cam?
Also is it possible to use Arducam Multi Camera Adapter Doubleplexer Stereo Module V2 or Arducam Multi Camera Adapter Module V2.2?
Thanks for asnwers! 
In openhd 2.x the camera system is designed around a pi camera as the main cam, and then any other kind of camera as the secondary, which can be switched on and off with an RC channel.
In addition to that you can opt to use that 2nd camera all the time by making a file called air.txt on the SD card.
In 3.0 you’ll be able to use whatever cameras you want in any combination.
There are a few kinds of arducam splitters/switches, they have one that you just connect 2 cameras to and it splits the screen, then they have some others that switch with a GPIO, we have support for those as well.
Thanks! So as I understand Arducam Multi Camera Adapter Module is not supported in current version and will be available only in version 3.0?
Also trying to find a way to connect thermal camera. Found a encoder witch encodes video in h264 from AV input. Link bellow.
https://www.amazon.ca/INEBIZ-Professional-Camera-Hardware-Encoder/dp/B077NR11FF
How can I use the rc to control the gpio on the ground to output high or low levels?Do I need to add anything to the openhd source code and if so, how?