I'll echo comments made by others here about the possible downside to turning a hobby into a business. My experience wasn't in electronics but in automotive. Back in 1999 I discovered the Jap performance car world and bought a Mitsubishi Evo 6. I was blown away by it's performance and capability, it changed my life! Before that I was all about German cars, just no awareness of the Jap stuff. Soon I was modifying my Evo and the performance became even more incredible. Got really into it, engine, suspension, brake and all sorts of mods. At the time we had a family business in a fairly large industrial unit, so I set up a 2 post lift and workshop facilities so I could work on the Evo more easily. Then, via conversations on the Evo forum a few other owners asked if i would fit parts to their cars for beer money. Very soon that mushroomed into lots of people asking me to do work as my reputation for quality, conscientious work spread. Initially it was real fun, loads of people hanging out, bench racing about car stuff, and getting paid quite well, although it meant I had to work evenings and weekends to avoid conflict with the family business. Eventually though it became really hard work and I started to get 'difficult' customers who were very unpleasant to deal with. I never had time to work on my own car and the workload was relentless, I started to enjoy it less and less.
I had to take the decision to either continue and turn it into a stand alone business with extra people etc, or let it go and only take work from a few carefully chosen customers, actually friends by then.
Thats what I did, and I'm glad I did. The enjoyment of my own Evo returned and I only took the work I wanted to do, and on my terms.
Long time ago now, still have the Evo and a few very good friends to reminisce with!
So, I would think carefully about hobbies as a business.