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Still Drawing Circuits On A Napkin? Try Scheme-it Instead

Still Drawing Circuits On A Napkin? Try Scheme-it Instead

Ever since cloud-based services like Salesforce and Google Docs began replacing their well-entrenched desktop counterparts, there has been much speculation as to when EDA software might also make the transition to the cloud.

A lot has been written on the prospects for increased collaboration, and the new business models that could follow suit, benefitting both users and developers of design tools. However, there has not been much progress in this space -- even in the domain of simple schematic tools.

According to Randall Restle, the director of design support services for Digi-Key, this is because EDA tool vendors have traditionally focused almost exclusively on integrating more engineering functionality into their products, veering increasingly into mechanical features such as 3D visualizations for clearances or thermal transfer, while ignoring the benefits of collaboration that could surround their tools. “It’s surprising they haven’t evolved to web-based means of development because they can,” said Restle.

Now Digi-Key, the electronic component distributor, has decided to venture into this space with Scheme-it, a free web-based schematic drawing and diagramming tool (see Figure). Designed using HTML5 technology, the tool runs freely in any browser without requiring additional plugins to operate.

Restle described Scheme-it as a tool that allows engineers to work collaboratively to generate and share schematic drawings in a familiar circuit design framework, adding that it’s meant to replace the “napkin stage” of the design process where engineers are fleshing out ideas early on.

At this early stage, hand-drawn circuit diagrams often serve as top-level conversation pieces, which are typically thrown away and recaptured in a tool that’s more conducive to generating a prototype or production-quality design. Aspen Labs, the company that developed the technology, described Scheme-it as a sort of “Visio for electronics”.

Scheme-it allows users to share and embed these schematic diagrams on the web, making it useful for generating diagrams that can support a question to a remote colleague or on a public forum that might ask ‘what is the best way to bias this class-A amplifier?’. And designs can be saved or exported to a PDF or PNG.

As a schematic drawing and wiring tool, Scheme-it is implemented well. Parts placement and wiring is impressively fast, and net routing is intelligent. Sharing to a social site is as simple as pasting a URL.

Right-clicking on a part allows users to enter part properties including its reference designator, value, part number and Digikey part number. This information syncs with the bill of materials and can be toggled on or off in the schematic.

The library has a wide range of symbols for analog, digital and RF design. Devices range from passives, discretes (MOSFETs, BJTs) and amplifiers to digital gates, multiplexors, and microwave parts. There is, however, no efficient way to create a part other than drawing it from primitive elements.

Another drawback is that the part library contains only contains generic symbols, rather than any specific orderable parts. Adding numbers and properties manually for every component on the schematic can be a tedious process. It would be beneficial if the library could integrate with Digi-Key’s catalog, both for symbols and pricing and availability.

Another feature that would make Scheme-it more useful would be the ability to export a netlist so as to continue to be able to work on a design in a more fully featured EDA tool. And some other basic features like design rule checks, or multi-page support would also be welcome.

But Scheme-it is not meant to replace tools that cost thousands of dollars. Restle explained that where the tool falls short in functionality, it will make up for in architecture: EDA tools simply don’t provide a way for their users to design online in a way that requires no installation.

He also added that there’s no technical reason why these features couldn’t be added in the future, since it’s the drawing of the schematic that is most server intensive. “Where we take this is going to be based on how it’s received by customers. And we think this alternative online model has some value that the mainline tools don’t have,” said Restle.

One of the benefits that Restle sees with cloud-based tools is the ability to outsource the responsibility of managing and organizing data, such as part libraries. “Think of how many firms and individuals have all organized a library of parts. There’s a tax on us all for that,” he said.

Aspen Labs co-founders Cody Miller and Joe Wolin, who also run EEWeb, said that the tool arose from a need they saw, which was for a way to share and embed clean schematic diagrams on the web, rather than the unclear screen shots from CAD tools they were frequently seeing. The founders are also working on other web-based tools.

“Online tools are the future, and it hasn’t been that well tapped. Some of the big EDA vendors - Altium with Vault and other vendors out there -- are trying to come up with ways so that designs are stored online and you can access them anywhere,” said Miller. “But our approach is to provide free online tools. And the availability of a tool on any machine and the access to your designs will be a technology changer.”

Digi-Key and Aspen Labs aren’t the first to venture into cloud-based capture tools. Upverter, a startup from Toronto, launched last April with their HTML5-based schematic capture tool. Founder Zak Homuth said that their user base is largely students who see the benefit in collaborating on schematics and exporting images of them, and don’t need to do things like actually create boards.

At DesignCon last week, a couple of other tool vendors I spoke with hinted at their cloud strategies, or at least their belief that online tools will be in the future cards for EDA. Right now, Scheme-it sees only about 500 users a week; however, Digi-Key said that the design tool is still in its early stages.

So perhaps 2012 will be the year in which we finally see more upstarts, and also big vendors, make the leap into the cloud.

TAGS: Digi-Key
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