There are plenty of USB microscopes available. Just don't get sold on a model because it has 200x capability. We don't want to look at the amoebas crawling around on a coin. However, you should be aware that most USB scopes aren't very good for taking whole-coin images larger than a cent. Chris
I took this photo with a 10x loupe and some zoom on my phone's camera. I don't think you really need a microscope to take photos of potential errors...
This thing works well for really cheap...I have a Samsung galaxy 1 as well. https://www.cointalk.com/threads/just-save-at-least-50-bucks.262757/