FIGURE 24.2 The Gertboard plugged in to a Raspberry Pi.The Gertboard contains circuits for experimenting with many common features of the Raspberry Pi:
12 buffered I/O ports
12 LEDs for displaying logic levels
Three push-button switches for input
Six open collector relays for turning higher-voltage circuits on and off
An 18v, 2A motor controller
A two-channel analog-to-digital converter
A two-channel digital-to-analog converter
An Atmel ATmega microcontroller (just like the Arduino)The Gertboard is designed as a modular board with pins that interface to all the onboard components.
Setting up a circuit is as easy as connecting wires between the pins on the board. The Gertboard kit
comes with a set of jumpers (short clips that connect two adjacent pins) and a set of straps (longer
wires that connect two pins).
To use the Gertboard, you need to become familiar with the pin layout on the board. Each group of
pins is identified by a J number that you see written on the circuit board. Table 24.2 shows what each
J block of pins is used for.