The Arduino Prototyping Shield makes it easy for you to design custom circuits. You can solder parts to the prototyping area to create your project, or use it with a small solderless breadboard (not included) to quickly test circuit ideas without having to solder. It's got extra connections for all of the Arduino I/O pins, and it's got space to mount through-hole and surface mount integrated circuits. It's a convenient way to make your custom Arduino circuit into a single module.
Board features as follows:
1.0 Arduino pinout
1 Reset button
1 ICSP connector
14 pins SMD footprint (50 mils pitch)
32 double row through Hole pads, standard Arduino breakout layout
Proto aerea with multiple THT pads, 100 mils pitch
The Proto Shield bring the power from the Arduino standard 5V and GND pins to the two power bus rows placed between the Through Hole package footprint, which can be used for powering the DIP sockets, or for power and ground rows.
The maximum length and width of the Proto Shield PCB are 2.7 and 2.1 inches respectively. Three screw holes allow the shield to be attached to a surface or case. Note that the distance between digital pins 7 and 8 is 160 mil (0.16"), not an even multiple of the 100 mil spacing of the other pins.
On the ICSP connector only 5V, GND and RST are wired to the respective pins on the header. MOSI and MISO are present only on the connector pads.
For more information about the SPI communication see the SPI library.