if you want to build your own controller, there is a few things you should know.
1. the general principals of electron flow.
2. inductive and capacitaqnce reactance principals.
3. ac and dc theory.
4. digital logic
5. bouline theory with a bit of demorgan's theorum.
6. basic microprocessor architecture.
7. component numbering schemes and data sheet interpretation.
just to mention a few, there is also the skills of attaching this stuff together.
like everything else, you have to crawl before wou can walk.
you can also take a ready made design and build it.
this is a learning process, with a great feel of accomplishment and it take out all the theory bookwork.
and this is the right web sight to start.
just go for it, if you don't try, you'll never know.
if you do it your self, you will have complete controle.