Some engineers are not drawing the line at circuit boards and are extending open source all the way down to the level of chip design. Modelling digital integrated circuits using hardware description languages (HDL), members of the Opencores community are designing everything from RISC microprocessors and Gigabit Ethernet controllers, to multimedia and cryptographic hardware. The resulting intellectual property cores – so-called due to the copyright in the design's source code – are then made available under a licence such as the LGPL or BSD, and are often modular in nature and so can be combined to create a system-on-a-chip.
You may wonder why anyone would do this when the start-up costs associated with having your own chip manufactured are so high, but designs are mostly implemented using off-the-shelf reconfigurable devices called field-programmable gate arrays (FPGAs). These contain logic blocks that can be configured to provide something as simple as an AND gate, or as complex as the combinational logic used in an ALU, along with reconfigurable interconnects that are used to wire the blocks together. Configuration of the device takes place on power up when it loads a binary file that has been generated from the HDL design, and this is stored in a small amount of flash memory; this can be replaced with ease, thereby making it trivial to test and upgrade designs.
The price/performance of a general purpose computer built using FPGAs wouldn't be great when compared with commodity gear, but the technology excels in many niche and specialist applications, such as in areas of computing that make use of dedicated hardware to bring high performance to tasks such as signal processing, encryption and networking. Since you can program many hardware paths in an FPGA they are well suited to jobs that can be broken down and processed in parallel, and some of the more powerful devices pack millions of logic blocks and have a transistor count well into the billions, with a blisteringly fast serial bandwidth that is measured in terabits/second. The fact they are easily reconfigured means that they're also well suited to prototyping designs before a custom application-specific chip is manufactured, and they make an ideal platform for use in learning digital integrated circuit design.
OpenRISC is heralded as being the flagship project of the OpenCores community and is developing a “family of 32- and 64-bit processors with optional floating-point and vector processing support”. While much end use of these processors will be via FPGA, the project has seen them employed by Samsung in custom chips manufactured for digital televisions, and has raised over $20,000 towards the cost of having its own system-on-a-chip manufactured. It plans to make this device available to the community at low cost, with the aim of providing an alternative to “semiconductor giants who only provide cost efficient prices to large multinational companies”. The world's first ever community designed ASIC, this could be used in anything from a prototyping platform similar to Arduino, to a TV set top box or a tablet computer.
Global Village Construction Set
What would it take to build a sustainable civilisation with modern comforts from the ground up? This is a question that a network of farmers, engineers and supporters going by the name of Open Source Ecology (OSE) hope to answer with the Global Village Construction Set (GVCS) – a collection of open source designs for 50 industrial machines that are low cost, simple to construct, modular and user-serviceable.
The GVCS is organised into categories of Habitat, Agriculture, Industry, Energy, Materials and Transportation, with designs ranging in complexity from something as simple as a nickel-iron battery to an industrial robot. Likened to “life-size lego”, these are woven into “product ecologies” which illustrate how the 50 tools will work together. For example, the Power Cube can be used as the energy source for the Car or Tractor, and the CNC Circuit Mill can produce circuit boards for any machines which have electronics.
Development of the GVCS is informed by a list of core values that stipulate things such as how machines must be user friendly, have industrial efficiency, use proven techniques and be capable of being recycled. There are 49 values in all and these form part of even more comprehensive specifications covering everything from materials sourcing and systems design, to economics and business models. As you might expect, OSEs provide a position on patents (deemed unnecessary) and licensing as part of these specifications, along with guidance on how to go about documenting designs in a way that makes them easily reproducible.
OSE has set itself the ambitious target of releasing all 50 designs by the end of 2012 and within an extremely modest budget of $2.4 million. At the time of writing, advance orders were being accepted for four machines: the Soil Pulverizer, Compressed Earth Block Press, Power Cube and Tractor. The Bulldozer, CNC Torch Table and five others are currently in the prototyping stage, and the remainder are either in or awaiting the start of development. The web site suggests that additional subject matter expertise is currently required in areas such as mechanical engineering, power electronics, machine design, metallurgy and precision engineering.
OSE's stated core message is “Creating tools for building modern off-grid resilient communities that can be reproduced by anyone at low cost”, and the GVCS could equally be put to use by developing nations or by those in the developed world who aspire to live “off-grid” and independent of large-scale manufacture.
Perhaps one of the most exciting GVCS concepts is the idea of product ecologies where there is a clear symbiotic relationship between tools. This is something that is also evident in projects such as RepRap, where one machine can print the parts for another, and an Arduino can be used for the RepRap control electronics which can in turn print an enclosure for an Arduino. But the GVCS takes this to the next level by encompassing a great many more technical disciplines and by putting an ecology of machines at the very heart of its design.