Raspberry Pi A, User Manual, Page: 269 / 314

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Figure 16-3:
The Slice of Pi,
connected to the
Pi’s GPIO port
The disadvantage of the Slice of Pi lies in its simplicity. Its compact size means that it is unsuitable
for the creation of larger or more complex prototypes, and while the header layout provides some
protection against short circuits, there’s no protection against the use of 5 V components that can
damage the Pi’s 3.3 V logic circuits. The labelling is also different to that used to typically describe
the Raspberry Pi’s GPIO pins, which can lead to confusion when using a GPIO library not written
with the Slice of Pi in mind. Table 16-1 provides a mapping from one labelling system to another.
Table 16-1: Slice of Pi GPIO Mappings
Physical Pin Number Official Designation Slice of Pi Label
7 GPIO Pin 4 (or General Purpose Clock 0) GP7
11 GPIO Pin 17 GP0
12 GPIO Pin 18 GP1
13 GPIO Pin 27 (21 on Revision 1 boards) GP2
15 GPIO Pin 22 GP3
16 GPIO Pin 23 GP4
18 GPIO Pin 24 GP5
22 GPIO Pin 25 GP6