Odd pad on mbed LPC1768

18 Jan 2012

I've noticed an odd through-hole pad on my mbed 1768 and I would like to know what it does (or more accuratly where it connects. I've scoured the schematic but can see no reference to it at all. It is located between the northeast corner of the LPC micro and the pin pair p29-p30. Anyone have any clues? I suppose if I was really desperate to know i could manually find the continuity between it and every other pad on the board. But before I do that I was hoping one of the mbed engineers might point me in the right direction first. Thanks for your time!

19 Jan 2012

I doubt it is electrically connected to anything (maybe ground?). During the manufacture, the pick-and-place machines need a reference point on the board. These are usually bare pads (for high contrast) on opposite corners of the board, but they can be anywhere. It is likely that this is what its for.