It all started with quite a complex PCB that I have been developing with Eagle CAD. A 4-Layer PCB with a lot of parts (>100) and quite a few ICs with a lot of pins. All these traces, all this pins and pads. There are so many possibilities to screw it up, that I always thought about this sentence all of you interested in this kind of stuff know well: "Hardware is hard". It is. And after triple checking every pin and trace, working through dozens of data sheets and controlling pin layouts I had it in front of me: My very [...]