Datasheet

which have two signal pins simultaneously, separate your wires so that an empty socket is between
them, like this:
Wires for two signal Grove modules cannot sit side-by-side on the Base board because one pin (such as
D2) will be shared with adjacent sockets. However, if two Grove only use one digital pin each, such as
the tilt switch and the piezo, they can use adjacent sockets on the Base board, since they only use one of
the digital lines in the connecting wire and therefore will not interfere with the other. It is the same as
the Analog I/O sockets. Make sure you know look at the silkscreen of each socket before you start
wiring.
(Note: The starter Kit v1.0b does not have two signal pins Grove modules)
Grove units
Each "Grove unit" is a peripheral board that connects to the Grove System Grove - Base shield using a
consistent 4-wire connectorised cable. The connector leads are Ground, Vcc, D2, and D1, where the D1
and D2 leads may be digital or analog input or output, depending on the equipment on the Groves. The
same format also supports I2C (IIC) signalling, and several of the Base shield connectors are tied to
Analog pins 4 and 5 to support it for future I2C-based Groves .
Most of the Groves use a 2cm x 2cm format, looking like jigsaw puzzle pieces which fit together with
tabs, and bring the Ground and Vcc out to the corners and the D1 and D2 out to each side.