Improve ReadMe

[Minimal-C]

Hi, I'm a software engineer at Andor and I came across this repo. I see it hasn't been updated in a while, but if it's still active I think I can help clear up some unknowns here to improve your readme.

I'm speaking in an unofficial capacity so if you require proper assistance you can contact us through https://andor.oxinst.com/support/

Bitflow Kernel Compatibility

The Bitflow framegrabber card requires the user to build and install the bitflow kernel module (bitflow.ko) in order to use it. This is done during installation of the Andor SDK3. This bitflow module is only supported on kernels up to v4.6, and requires the V4l2 module (sometimes part of a extra modules package). This is the reason it does not work on newer kernel versions. Another thing to note, if you previously built the Bitflow kernel module with a kernel > 4.6, then rolled back to a compatible version, you have to uninstall and reinstall Bitflow (commands for this can be found in the bitflow subdirectory in the SDK3 install directory). Otherwise it will attempt to use the kernel module you originally built, which will not work.

Strange behavior on Debian

I'll start with the preface that Debian is not officially supported by Andor when using SDK3. But with that said, I have personally used it a little as have other customers, and there are a few caveats to know when doing so:

• ldconfig not found The problem with "ldconfig not found" is related to an internal SDK3 shared library search mechanism. It basically expects ldconfig to be available from the terminal session, which it is in many Linux distributions, but in Debian it is not (unless you are sudo). This can be rectified by making ldconfig available to the user e.g. by adding /sbin to your $PATH.
• Installation Issue (Automatic and manual platform detection fails) There is also another potential issue when attempting to install a newer SDK3 version on Debian. There was a bug in the installer which prevented the platform from being automatically determined correctly and the fallback "Please select platform to install" prompt did not function correctly. Which results in the installer failing. This can be resolved by modifying the install_andor bash script to hardcode your required platform. This was fixed in newer SDK3 releases but there is a small window where this issue exists for Debian users (Early SDK3.15 releases).

Preparation of the Linux environment

When downgrading the Ubuntu 16.04 kernel to 4.4 it may be easier for users to install it through the apt package e.g. "linux-image-4.4.0-193-generic" rather than a mainline kernel. In https://wiki.ubuntu.com/Kernel/MainlineBuilds they state: "These kernels are not supported and are not appropriate for production use". I have no real issue with using mainline kernels in this case, but it would be nice to offer an alternative using apt which are officially supported by Ubuntu. However, if the user wished to use Ubuntu 18.04 they would be forced to use the mainline builds system to get a 4.4 kernel as this kernel is not available via apt on 18.04.

[tfarago]

Thank you so much for your input! It will be certainly helpful in the future. Currently, there are no active maintainers of this repo, but when some picks things up I will point them here.