πββοΈHey~I'm a student who majors in EE at UESTC. I saw your attractive project on Youtube and wanted to do the same project according to your open source files.
However, when it comes to SMT, there is a problem remaining solved. The SMT factory needs to know the polarity of the photodiode. There are only two possibilities, which one is right?
A:

B:

Could you tell me the right answer? Thanks very much~~~π