I thought writing a Hello World in C++ was easy, until I had to make one that is transmitted by 2 synchronized I2C masters sharing nothing else but a 7 bit I2C slave memory. All I found about multimaster I2C is that it isn't possible or even practical, well.. Hello multimaster-multislave I2C!
(2020) Discussion at the time (212 points, 133 comments) <a href="https://news.ycombinator.com/item?id=21954886">https://news.ycombinator.com/item?id=21954886</a>