Here’s the circuit board that is at the heart of my LC3+ light integrator.
Long ago I lost count of how many hours I invested in this design, but it must be thousands of them; plus lots and lots of design iterations and huge amounts of testing.
The tiny square chip in the middle is the microprocessor. This has more power than the entire computer room I looked after in my first job. My code running on it weighs in at almost 20,000 lines of C++, all to ensure that UV exposures are spot on every time.
When I studied engineering (many years ago), PCBs were big clunky things with giant components. Back then I wrote code in assembly language, and just getting LEDs to display meaningful data was an achievement.
So much has changed!