I2C diagram difficult to read in dark themes

[grodin]

This affects the original discovery repo too, but I thought you'd rather have issues over here.

The diagram on the I2C chapter page (rendered url is: https://docs.rust-embedded.org/discovery-mb2/11-i2c/index.html, source file is at https://github.com/rust-embedded/discovery-mb2/blob/main/mdbook/src/11-i2c/README.md ) is difficult to read in any of the darker mdbook themes.

The screenshot demonstrates the Navy theme, but the other two dark themes are similar.

It's a separate issue really, but the diagram is referenced directly from Wikipedia, which doesn't seem ideal, so maybe the image file should be in the assets directory once it's fixed?

I'm happy to help with this, though I don't have much experience of mdbook (more than willing to learn though!)

[grodin]

The same image with the same issue is also at https://docs.rust-embedded.org/discovery-mb2/11-i2c/the-general-protocol.html

[BartMassey]

Thanks! I suspect we'll just make the image(s) have light backgrounds even in dark mode rather than using alpha. Pull request welcome, else I'll try to get to it soon.

[grodin]

Just to let you know, I'm intending to send a PR for this, just haven't had a lot of time

[BartMassey]

No prob! I'll get it eventually if you don't. Kind of heads down in the new chapter for the last few weeks, sadly, and don't really want to touch other stuff until I've finished with it.