Operation Manual

Perhaps the most important feature of the Gertboard is the protection it offers to the Pi. Using a 3.3 V regulator, the Gertboard is
designed to prevent the Pi’s GPIO port from receiving voltages it cannot handle. Like the Slice of Pi, it also attempts to restrict
access to the six pins labelled Do Not Connect as well as the 3.3 V and 5 V pins to help prevent accidental shorting. Although
care must be taken while wiring up circuits, following the instructions included in the Gertboard’s user manual guarantees the Pi’s
safety.
The motor controller functionality of the Gertboard makes it easy to integrate the Pi into a robotics project. It’s suitable for
motors of up to 48 V at 4 A, which is easily powerful enough to drive a small robot vehicle. Sadly, the motor is not included as
standard with the Gertboard. Instead, you are asked to supply your own controller—with the L6203 package being
recommended—if motor control forms part of your project. With the motor controller soldered into place, the Gertboard can be
used to control surprisingly powerful motors either through instructions received from the Pi itself or from the optional Atmel
microcontroller module. Figure 13-9 shows an example circuit that’s using the Gertboard to drive a 12 V motor from a battery
pack power supply.
Figure 13-9: Using the Gertboard motor controller
For project building, the Gertboard offers significantly more functionality than a bare Raspberry Pi. The 12 buffered IO ports,
located at the top of the board, can be configured as inputs or outputs and provide more connectivity than the seven or eight
general-purpose IO pins provided on the Pi’s own GPIO port. The inclusion of LEDs, which indicate when a pin is high or low,
helps with both circuit troubleshooting and electronics education, making it easy to see what the various inputs and outputs are
doing at any given time.