The Gertboard expands the capabilities of the Raspberry Pi's GPIO port - but it doesn't come cheap.
The Gertboard add-on for the Raspberry Pi microcomputer has been officially launched, with distributor Farnell advising of a two-month lead time for a kit-form version.
Designed by Broadcom engineer Gert van Loo, the Gertboard is designed to connect to the Raspberry Pi's general purpose input-output (GPIO) header in order to provide significantly improved functionality including analogue-to-digital conversion and motor control with no additional parts required.
Previously available only in limited numbers as a prototype, van Loo has revised the design of the board extensively in order to improve its functionality. In its finished form, the board includes buttons and LEDs for instant feedback and control, analogue-to-digital and digital-to-analogue converters for more complex projects and an in-built H-bridge motor controller.
If that little array of accessories wasn't enough, van Loo's updated design includes an integrated Atmel microcontroller - the same chip which sits at the heart of the Arduino board. Programmable directly from the Pi's GPIO port using the Atmel AVR software development kit (SDK,) the chip gives the Pi real-time sensing and control capabilities missing from the original design.
The chief design ethos for the Gertboard, van Loo explains, was to create a device designed explicitly for learning how to control input and output devices. 'The first step is to deal with the I/O directly, read a button or drive an LED. The second step is to deal with the I/O indirectly where you talks to a block which then talks to the outside. The third step in handling I/O is to talk to a processor which talks to a block which talks to the outside world,
' van Loo explains of his methodology. 'That is where the ATmega comes in. As you can see, the board is not an arbitrary bundle of electronics but has been designed with a clear teaching path.
Provided in kit form - teaching the essential skill of soldering as an added bonus - the Gertboard includes all the necessary components, a cable for connecting the board to the Pi's GPIO header, 20 example programs and a digital 43-page manual.
Sadly, the complexity of the Gertboard does come at a price: Farnell are currently taking pre-orders for £36 including VAT, making the add-on board around £6 more expensive than the Pi itself.
More information, including international ordering details, are available on the element14
site - but be warned: the Gertboard has already taken enough orders to extend the lead time from the original few weeks to a full two months.