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.

As stephen_g pointed out, it's ok by the hardware exemption in https://news.ycombinator.com/showhn.html.

But I like the title Das Blinkenlights so have changed it anyway. @boznz: I hope that's ok!

(The post is currently at #3 on the frontpage so there's not much need for it to be high on /show in any case.)

All good with me. Just assumed others might want to build one. Lots of empty rack space out there that might not mind shedding a few extra watts for some color. Also its nice to get noticed every now and then even if it is for the crappy stuff :-)

Oh wow, I never read that and thought Show HN was simply, "Look at this cool thing I did."

It basically is! but the rules provide a few guardrails.