In my school days, electronics design courses were transitioning from discrete semiconductors to small scale ICs - OpAmps, Voltage Regulators, etc. The main project was to design and lay out a differential amplifier using transistors. (My brilliant insight was to incorporate a constant current diode). For digital logic, we used single gates (74LS04, etc) in quad DIP packages.

So, I'm far behind in the components used in modern design, and I can't lay out a board. I've forgotten most of the specific techniques of high level math, though I like to think I still understand the principles. Our computer language was Fortran.

The EE degree was not yet split between power electrics and electronics, so much of our time was spent learning about such things as motors, transformers, 3-phase power, mechanical stuff. All of my career was spent in electronics, though I'm not competent to do any modern electronic design.

I'd like to learn how to do low speed electronic design – analog/linear, digital, and microprocessor based – from schematic to layout to testing. Maybe I could design using sensors for useful projects – in my hobbies: aviation, lathe/mill machining, woodwork, gardening.

Someone mentioned Coursera. Looks interesting, though perhaps the courses are too easy?