Comment by stephen_g
I disagree, on the very same page it says:
> On topic: things people can run on their computers or hold in their hands. For hardware, you can post a video or detailed article. For books, a sample chapter is ok.
While it's posted on a blog, I would say it meets the criteria for having the video and write-up showing off the cool thing that has been built.
I think what that page is saying about blog posts is that you shouldn't post a Show HN as a 'look at this blog post I made about [some random topic]', as in when it's the blog post itself that you're showing off. It's not saying you can't post any blog post as a Show HN.