hi
recently i got a few of these nrf51822 boards (nrf51822 is a cool bluetooth le 'solution')
the trouble is that the pads for pins on the edge is spaced at 1.27mm pitch, they are somewhat too closely spaced would probably need to 'breakout' further to say 2.54mm pitch to work more conveniently say to patch 'dupont' connectors
initially i looked at these single row 'header strips'
however, the header strips don't really solve the problem as they are still spaced closely and seemed needs an 'interface board' to breakout further
i'm now thinking about using ribbon cables instead
how do you normally use these tiny boards? what are the good ways to patch those edge connecting pads? would it be difficult to solder wires to those 1.27mm pitched connecting pads given the close spacing? i'm thinking that even a little more solder may just short adjacent connectors
Those pads along the edge are called "castellated pads". You solder it onto a larger circuit board that has matching pads - hackjobs involving soldering pins or wires to castellated pads are not recommended - the result is fragile, and it's a difficult soldering job. Modules with castellated pads on them are frequently used in cases like this where the chip needs more difficult design work (RF design), to make it easy to incorporate into a PCB design.
I don't immediately see any breakout boards for that version of the nrf51822 if you want to use those without making a custom circuit board - they may exist. nrf51822 breakout boards that have the pins connected to 0.1" pitch holes are readily available on ebay.