The Gertboard is an input/output expansion board for the Raspberry pi that connects to the
GPIO port. The Gertboard is laid out in usable blocks for various functions to detect and
control connected devices, drive motors, detect and output Analogue voltages, drive
relays, detect switch presses and control LEDs.
- 12 buffered input and output ports
- 3 x push buttons
- A motor controller 18 volts 2 amps
- 28 pin dual in line AT mega micro controller
- 2 channel 8, 10 or 12 bit Digital to Analogue converter
- 2 channel 10 bit Analogue to Digital converter
The blocks are only connected to the power supply of the Raspberry Pi's GPIO port.
Straps and jumpers are then used to connect the functions of the Gertboard to the Raspberry Pi's GPIO
port allowing you to configure the layout as required for your project.
The Gertboard is controlled by program's written in C and python that access the Raspberry Pi's GPIO port. The micro controller can also control the Gertboard once it has been programmed using a custom set-up of the Ardunio IDE.
Sample C and python programs are available for download to test the Gertboard.
See the links at the bottom of this article for more information on the sample programs and the Ardunio IDE custom setup.
12 Buffered I/O ports:
The Input/output ports are used to send inputs to the Raspberry pi and receive outputs.
There are 12 LEDs and 3 push buttons that can also be used with the I/O ports
6 Open collector drives (50V, 0.5A):
These are used to switch on and off externally connected devices that have their own
power supply. Each port can withstand up to 50 volts and 500mA.
18V, 2A motor controller:
The motor controller can be used with brushed DC motors up to 18 volts and 2Amps,
either powered from the Gertboard or with an external power source. The Gertboard is used
to control forward and back rotation of the motor, the Raspberry Pi can be used to
control the speed via the GPIO port.
28 pin duel in line ATmega micro controller:
The Gertboard can use various Atmel micro controllers using 3.3V. Most commonly the
ATmega168 and ATmega328 but you can also install the ATmega48, ATmega88.
These micro controllers can be programmed using the Ardunio IDE, a custom version of a
avrdude for the Raspberry Pi. Once set-up the micro controller can be programmed to
manage a specific task and control the Gertboard independently from the Raspberry Pi.
As the ATmega is in a socket, the Gertboard can be used to program the micro controller which can the be removed for use in other devices and projects.
2 channel 8, 10 or 12 bit Digital to Analogue converters:
The Gertboard uses the MCPxx digital to analogue converters. The MCP4802 for 8 bit
conversions, the MPC4812 for 10 bit and the MCP4822 for 12 bit.
2 channel 10 bit Analogue to Digital converter:
The MCP3002 10 bit analogue to digital converter is used with a sample rate of around
72k samples per second.
A PDF user manual is availabel from Farnell Element14 here
Links to the C and Python sample software are on the RaspberryPi.org forum here
Details on how to use the Ardunio IDE with the Gertboard can be found at projects.drogon.net