In Linux User & Developer this month, in addition to my usual four-page spread of the latest news from the open source, open hardware and open governance spheres, you’ll find a review of a new add-on board for the Raspberry Pi: the GertDuino.

Developed by Gert van Loo, the GertDuino is a slimmed-down and simplified design based on the microcontroller-powered portion of the Gertboard – originally reviewed way back in Linux User & Developer Issue 121 from December 2012. Unlike the Gertboard, the Gertduino is a zero-footprint design which sits entirely on top of the Pi to expand the capabilities of its general-purpose input-output (GPIO) header.

Powered by a pair of Atmel microcontrollers – a primary ATmega328 and a secondary ATmega48 – the GertDuino offers full compatibility with Arduino Shield add-on boards, the ability to run stand-alone in Arduino mode, and a variety of other snazzy features including an on-board real-time clock with optional battery backup and a bidirectional IrDA interface. Both these latter features are powered by the ATmega48, allowing the more technically minded user to put the Pi and the ATmega328 into a low-power sleep mode pending a wake-up interrupt from the ATmega48.

There’s no denying the Gertboard is a clever design, but it does fall into several of the traps of its predecessor. Switching between the board’s various modes is achieved using unlabelled jumpers, while one of the most handy modes – the ability to query Arduino Shields which use serial communications directly from the Pi – requires optional jumper straps which then get in the way of mounting the Shield itself. Documentation, too, is poor – and aimed primarily at those with embedded development or C coding experience already.

Is it worth the price of admission? Well, you’ll have to buy Linux User & Developer Issue 135 to find out – either from your local newsagent, supermarket, or digitally via Zinio and similar distribution platforms.