How about this for ingenuity. NWPipesmoker is a guy I follow on YouTube who lives in Washington State USA, home of Starbucks, and he had this idea that roasting his own coffee would be fun.
He shows you how to do it in this video and gets reasonable results from a hacked pop corn blower.
Luckily for us he concludes that roasting coffee is fun but the results are more reliable if you buy from a professional but hey I make my own beer but I still prefer the pub !
The video starts part way through, so you miss the pre-amble