I am building something where I needed some IO expanders. I have these modules sitting in my box of arduino crap and figured i could desolder the headers and reverse them and then plug these into my pcb board.
I got to starting on that when I realised, there is no annular ring on the top side of the board. There is no way to really solder the headers in the other way. Bloody stupid board designers doing stupid things like this.
Now to find a solution to my problem.