So to answer to your questions:
The main compatibility problem is that most model of itsybitsy don't have NAND storage, which is needed to store important calibrations data. (Not sure about all model tho)
Beside that for optimization purpose most of the library I use are especially written to work on the Atmega32u4, and won't work on other ones (the joystick mode for instance).
Although I never tried on the ItsyBitsy 32u4 specifically, which seems to be a clone to the itsybitsy 32u4? If it's a clone it should work as is.
The main reasons I choose the Atmega32u4 is that it's dirt cheap, has more than enough power and pins for this use, and has way more resources available than any other models.
Now the reason why I decided to not share the code;
I was indeed thinking about sharing it too like Samco did.
I did it for my 2 points sketch that added many more functions than his.
But you have to know that my sketch is massively different, way bigger and more complex. It took me hundred of hours to pull off the complex math needed to accurately and smoothly triangulate the aim position no matter the number of points (1~4), while taking care of other functions like rumble or recoil, all without any added lag or slowdowns.
With all the numerous functionalities I added and am still adding, this solution is pretty much the most advanced in the market, sinden included, thanks to the auto calibration, the ultra low latency (5~7ms), and the plug and play aspect (no need to have a video processing device a special tool/driver or anything else).
But I've worked as a dev long enough to know that if I release the sketch in the wild, there will always be people using that code to improve their own product or sell new ones. I definitely don't want people to make money on it.
So unless you know a way for me to protect my code, I won't share it
But if you guys want I can still make other firmwares compatible with different device or pinout.
So I decided that I had nothing better to do than rewire the gun and can confirm that tracking works at at least 3 meters (that's how long a cable I have) that's with the 3 led spots I made. No interference from other lights like the buttons on my arcade.
But as you might remember I didn't use the df robot camera but the wiimote one instead.
So it does not have a housing that I can just rotate, mine is locked in with glue.
the problem is that the entire coordinate system is mirrored which is the same as being rotated 180 deg.
You mean mirrored with my sketch? Or just as is? Did you test with samco's test sketch?
The DF Robot cams have a big tilts issue, they aren't correctly oriented.
But if you tell me how the axises are reversed I can make another firmware without the df robot inversion.