Today, I got a mail from Hackaday, telling that I should also put my sourcecode on the project page.

I am afraid that the sourcecode is not an easy read. It is based on software from older projects, and it should be cleaned up. I think you can tell from the code that I did quite a lot of assembly coding in the past...  

This evening, I translated several dutch comments to English. The real spectrum-analyzer work is in 'sa.c'.