Breaking Down the Barriers

Taking, adapting and creating new electronics hardware designs just got a whole lot easier. I look at how the free pcb design tool from RS Components, DesignSpark PCB, is helping to lower barriers to innovation and explore the pertinance to Open-source harware projects such as Arduino

Changes are afoot in electronics engineering.  Similar to the open-source software movement that has opened up access to a wide range of IT applications, open-source hardware is helping to remove a number of barriers to innovation in technology.  Unlike the open-source software community however, hardware designers wanting to open up their work haven’t had access to as many freely accessible tools of the same level – until now.

Open-source hardware (OSHW) makes it possible to take designs and make them without paying royalties or, more importantly, modify and extend them to build new things.  It means less time reinventing the wheel, implementing subsystems when someone who has done the work and provided it as an open-source design has already optimised those designs.

Companies such as Arduino have embraced the open-source hardware model to make it easier to prototype and develop new systems.  The core boards made by Arduino are supplied with all the documentation and source files needed to recreate them and to adapt them.

OSHW has made it past prototypes and into finished systems.  Openmoko kicked off the idea of building an entirely open-source cellular handset and the project has yielded not just a software stack but spawned a community effort to provide a reusable hardware design for a complete mobile device.  The MakerBot 3D printer, designed to construct plastic objects at home, is sold as a kit.  But the company provides all the design files and information needed to make one, or to improve on the design to create a better MakerBot.

Although there is a growing community of electronics and systems designers willing to open up their work and provide a head start to people with ideas on how to extend them, there has been a gap when it comes to design tools.  The open-source software community has access to many free tools to create new software.  However, before now, freely accessible tools for electronic hardware design have not reached the same level.  

There are a number of free PCB design tools but they frequently have serious limitations.  For example, they may have very limited export facilities because they are designed to be used only for a particular PCB manufacturer.  Often the free tools are license or time restricted products requiring a later purchase.  There are also open-source tools that can be downloaded from the internet.  These are generally free of artificial restrictions on attributes such as board size and number of layers a project can have.  But, being developed by a loose community of programmers, they can lack key features and the ability to quickly fix bugs that PCB software users have come to expect from commercial tools.  

DesignSpark PCB

DesignSpark PCB, on the other hand, is a free tool but with the attributes of a commercial tool that has not been artificially restricted in any way, whether you look at board size, layers, terms of usage, pin counts or file output.  Created in partnership with a third party EDA tools company, the development team totals over 150 man years of experience in PCB CAD software development and DesignSpark PCB is the result of this vast experience, together with feedback from design engineers and CAD users all over the world, plus detailed analysis of tools currently available for schematic capture and PCB layout.  As well as the schematic capture and layout features essential to any PCB design tool, DesignSpark PCB includes a full autorouter with full support for design-rule checks to ensure that the board is manufacturable.  As a result, it allows a new generation of electronics engineers to work on projects with a class of tool that would, previously, have cost hundreds or even thousands of dollars.  

The tool makes it possible to take a wide range of designs that are already available.  That is not just in the OSHW space but the many reference designs produced by manufacturers such as Texas Instruments, which provide design files compatible with industry standard tools.

In contrast to free tools made available to educational or hobbyist users, there are no usage restrictions on DesignSpark PCB.  It can be used for commercial designs as well as those passed to the OSHW communities.

Designed from the ground up for Microsoft Windows, DesignSpark PCB embraces the approach that the operating system recommends for application design.  This makes the tool much easier to learn.  When the software first opens, the user is not presented with a matrix of inscrutable buttons and commands.  Instead, the user interface is very clean with the core functions sitting on two icon bars to the top and to the side of the main screen.  Commonly used PCB design functions are available from context-sensitive menus.  

Because it was written for Windows, DesignSpark PCB fully supports copy and paste as well as drag and drop.  This makes it easy to take portions of a design file and transfer it to a new project.  If a reference design for a microcontroller has a section that you can use in a larger project, it is simple to copy it over.  Or the functions can be used to rapidly duplicate sections that would otherwise be very tedious to draw time and again by hand.

As DesignSpark PCB users are automatically part of the DesignSpark network, it is easy to get tips on using the tool as well as other aspects of PCB design.  Instead of hunting through documentation to work out how to get something done, you can find already answered questions or simply Ask for yourself.

And on to production

It is not the only way DesignSpark PCB is connected with online tools.  The tool makes it much easier to cost a design and get it manufactured through the ability to export a full bill of materials.   This BOM file can be uploaded to RS Components’ online quotation tool to fully cost a prototype or manufacturing run of assembled boards and then seamlessly order the necessary components.  

The tool is supplied with a full database of components, from resistors to microcontrollers.  If a component is not in the parts default database, it is easy to create a new one by selecting the relevant package type, such a SOT or a large land-grid array, and then assigning the pins entered on the schematic to their relevant positions on the package.

As many of the designs in the open-source world and not just components on PCBs, but robots, 3D printers and even an experimental hybrid car, how the electronics fit into the system mechanically is critical to success.  This is where DesignSpark PCB looks to the future.  The tool can take a PCB design and export IDF files, a format understood by mechanical 3D CAD tools.  

Many of the electromechanical components in the RS Component Chooser, which makes it easier to select which parts to use for a particular job, have corresponding 3D models.  Thanks to this, it is now much easier to for tools to incorporate the real 3D shapes into mechanical designs – so you can easily see whether a heatsink has enough clearance and, if not, nudge it to the right place with DesignSpark PCB.  A DXF import/export facility also allows you to import 2D representations of the 3D mechanical components and check clearances.  

Once the design is ready, DesignSpark PCB will generate a set of RS-274X Gerber files along with drill and documentation specifications that can be sent to any PCB supplier, providing the final link in the chain.  

Open-source hardware can change the way the engineering community looks at design – focussing effort on differentiable areas rather than forcing everyone to recreate common subsystems from scratch and lowering the barriers to innovation.  DesignSpark PCB removes another barrier by providing, for free, the ability to take, adapt and create new electronics hardware designs.

This article first appeared in the September 2010 issue of Components In Electronics

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