The success of the Raspberry Pi project has kick-started interest in low-cost Linux-powered single-board computers, but it has been surprisingly free of clone designs - until now.
Unlike rival development platforms such as the Olimex OLinuXino family or the popular Arduino microcontroller, the Raspberry Pi is not open hardware. Its design is locked-down and proprietary, and its principle components - namely the Broadcom BCM2835 system-on-chip (SoC) processor - not available in small quantities or without signing restrictive non-disclosure agreements. This may have contributed to a lack of compatible clones appearing on the market since its launch more than two years ago - until now, with two companies announcing Pi-compatible creations featuring considerably improved specifications: the HummingBoard and the Banana Pi.
First, the HummingBoard. Created by Solid-Run, the company behind the ultra-compact CuBox product line, the HummingBoard boasts the same features, design and layout as the Raspberry Pi - right down to the 26-pin general-purpose input-output (GPIO) header at the top-left of the board, which is pin-compatible with existing Pi accessories. Unlike the underpowered single-core 700MHz ARMv6 processor of the Pi, the HummingBoard boasts a quad-core 1GHz Freescale i.MX6 chip, 2GB of RAM - four times that of the Pi - and integrated Wi-Fi and Bluetooth connectivity. Additional enhancements over the Pi include an upgrade to gigabit Ethernet, an on-board real-time clock module, and an infra-red receiver.
The Banana Pi goes a step further. Created by OSSUG Company, The Banana Pi again duplicates the layout and footprint of the Raspberry Pi and includes both the 26-pin GPIO header and the smaller P5 header of its established rival. Although its 1GB of RAM and dual-core AllWinner A20 processor can't match the performance of the HummingBoard, the Banana Pi boasts an on-board SATA connector with 5V power output for mass storage. The board also includes gigabit Ethernet, an infra-red receiver, three on-board buttons and, interestingly, a microphone.
Thus far, the Raspberry Pi Foundation has been slow to offer an upgraded version of its award-winning single-board computer. The initial Raspberry Pi Model B was succeeded by a Revision 2 design which added the P5 connector and doubled the memory to 512MB but retained the slow single-core ARMv6 processor, while the Model A is a cut-down version which drops to a single USB port and loses the Ethernet networking chip. Its most recent product, the Compute Module, still uses the outdated BCM2835 chip - leaving the market open for Pi-compatible devices like the Banana Pi and HummingBoard that can offer buyers higher performance and more features.
Pricing for the HummingBoard has yet to be confirmed, with the Banana Pi available on import from Chinese resellers for $59 (around £35, a mere £7 more than a Raspberry Pi Model B.)