Building your own devboard requires skills in many interdependent areas. Have you tried using an Arduino or similar first? Having built computers from TTL chips and wirewrap chassis, I can confirm that digital electronics field has grown massively and requires knowledge in many specialist areas. Even designing a PCB requires a great deal of knowledge. Tools like KiCAD are great, but they don't abstract out the requisite underlying knowledge.
A university degree in any professional field is only the starting point for a lifetime of learning. In my pre-internet days I spent several thousand dollars a year on books and professional journals all of which I read cover-to-cover. With the internet I find all the materials I need with some focused searching.
The only thing that you truly learn at university is how to research, ie ask questions and then find the answers. Being a professional means having the experience to apply your learning to specific outcomes.
For me learning is very much just-in-time. I stumble across something I don't have a clue about, so I research. Typically I come across something that I don't understand, so then I dig into that and so on. Generally I need to get down into the weeds until I connect with something I already know. Then I start building upwards. Pretty soon I hit another thing I don't understand and repeat the exercise.
>Have you tried using an Arduino or similar first?
That’s why I went to uni to do EE/Robotics. I wanted the next step, suffice to say I did not get the next step from university.
I see what you’re getting at though. Just in time learning seems to be the way it will be. It’s just frustrating I don’t even have a base to go off of. Pretty much all my background knowledge has come from stuff I learnt outside of uni.
I know your pain. I'm the person who tries a dozen things and when none of them work, then grudgingly reads the manual, etc.
If your base doesn't help you launch, even in a small way, then you need to go below that base, back towards the fundamentals. I'm sure you learnt about logic gates, digital signals, transmission line effects, power glitches, etc. Unless you went to one of the well funded universities with youngish academics, then what you learnt was probably 5+ years behind the current state of the art. Add to that the years since you graduated. That is the knowledge gap in years that you need to traverse to establish an up to date base.
Until recently, I taught post-grad EE/SE (as an ex-industry, adjunct) at one of the country's top universities. My colleagues were dismayed at the inadequacy of STEM education of the first-year students. Year 1 has become a remedial school. Starting from such a low-level of knowledge 2-3 years doesn't provide enough time to teach all that is required to be successful in industry. In the field of digital electronics you typically need 3+ years of industry experience to become competent. Of course, motivated autodidacts can accomplish far more in far less time.
Listen to this person, this is brilliant advice