A quick tool for design ideas to hardware

November 16, 2015

A quick tool for design ideas to hardware

Makers, electronics hobbyists, and professional design engineers always have ideas, and I'm sure all of you have at least one sketched out on a piece...

Makers, electronics hobbyists, and professional design engineers always have ideas, and I’m sure all of you have at least one sketched out on a piece of scrap paper or in a notebook if you’re more organized. But that idea probably isn’t going to get very far stuck on paper – those sketches don’t turn into real components without a lot of extra effort. However, there are brainstorming tools that can actually help you go from ideas to real hardware in one place.

I recently came across Digi-Key‘s free browser-based electronic design tool called Scheme-it, which is basically a very flexible drawing program for electronic design brainstorming, or what David Sandys, Director of Technical Strategic Marketing at Digi-Key calls “an online back of the napkin.” In Scheme-it, you can design from the block diagram level, with system icons, and even at a traditional schematic level. Alternatively, users can start with a “Design Starter” that’s already fleshed out and modify it as needed.

Sketching out dev board ideas

While historically the tool has only included various components, in 2015 Digi-Key started to include low-cost development boards beginning with the Freescale Freedom platforms. (Find development boards to add to your design under “Manufacturers” on the left menu.)


Figure 1: A Freescale Freedom K64F Design Starter for a Nerf gun project.
(Click graphic to zoom)




“What we’ve done is we’ve placed the Freescale Freedom board symbols in Scheme-it and designers can start [designing] really quickly by leveraging all the expansion headers on those boards,” Sandys says.

Digi-Key is planning to add more open-source development boards including Arduinos, Raspberry Pis, STMicroelectronics Discovery kits, Cypress Pioneer PSoC kits, and others beginning in 2016.

“In this day and age people are leveraging modules as much as possible,” Sandys says. “It’s more of a LEGO approach to design, and as such there isn’t a tool that’s as easy to use as Scheme-it that can get you started with those headers and get you on your way to design.”

Choosing the right components

To add parts to a design, search for parts by type, vendor, or part number. Results pull from Digi-Key’s database of four million parts – and users can view the datasheets, application notes, white papers, user manuals, and other documentation on those parts. The search is already fairly thorough, but by the end of 2015 or Q1 of 2016 Digi-Key is adding a parametric search capability to make it even more intuitive to find the right part with the right features for what you need in your design. And if you have questions about a component or how to use it in a design, Scheme-it has a chat with Digi-Key’s technical team available 24/7.

When you’re done with a design, parts can be ordered directly from within the tool. More than one million of those components are available to ship immediately, even overnight to U.S.-based designers. And it’s easy to check to see if those parts are available with the shopping cart option so there are no surprises about a part’s availability.

“Engineers can feel comfortable knowing they can design with the parts, know that the parts are in stock, they’re available, and they’re not designing with something they can’t find,” Sandys says. “One thing design engineers hate is when they start using a part, and then they find that they can’t buy it. They spent tons of hours creating a design, working around that device, and there’s nowhere to get it.”

Lightweight browser-based tools versus desktop tools

As a browser-based tool, Scheme-it has to be lightweight – but that also gives it the advantage of designers being able to pull up a design from any computer by logging in to their account. And even though it’s not a heavy-duty desktop tool, the essential design tool features included allow for sketching out complex designs in minimal time. Sandys notes that whether a designer adds 5 components or 500 components ideas can be plotted out quickly.

“The whole idea behind Scheme-it is speed and flexibility,” Sandys says. “While the end game may be to physically create a PCB, design rule checking (DRC) every time you put a component on the design slows down the creative process.”

Checking features and simulation were left out of Scheme-its toolbox to keep it user friendly in a browser format.

“What we found is when you start dealing with parts that are out there like i.MX processors that have hundreds of solder balls on their ball grid array (BGA) package, that becomes a challenge to create those complicated layouts for PCB design in a web-based environment in real time, and to do it in a format where it’s acceptable to the user,” Sandys says. “So for that type of a tool where you really get that in depth of a design and you’re really doing those high-calculating, video-intensive applications, the web environment is not as great – a desktop environment is stronger.”

But if what you’re working on requires more complex features like DRC or SPICE model simulation, Digi-Key does have desktop tools for that: PCBWeb or PartSim.

If you decide you want to take your plan from Scheme-it and do more intensive work on it like DRC with PCBWeb, exporting and importing between the Scheme-it and PCBWeb tools is a feature planned to be released by the end of 2015.

Sharing for collaboration

Sharing, either of designs or of ideas to improve the tools, is another feature of Scheme-it. Importantly, designs are private as a default as well as password protected, so if it’s not something you want to share, your design is secure. However, there’s a lot to be gained from sharing, especially in open source dev kit communities and for collaboration among dispersed development teams.

“There’s no better way to explain concepts or collaborate or simply ask questions [in an open source community] than showing a schematic or a block diagram,” Sandys says. “We have an embed widget as well so designers can put the design directly into a blog and from that blog people can view the bill of materials or open it and play around with [a copy of] the design themselves. Designers can also have team members from around the world collaborate via a browser.”

Digi-Key also looks at community feedback from many sources, including the Scheme-it chat, social media, and talking to designers at shows, in order to determine what features the design community would want to help them in their design work.

“At a monthly basis at Digi-Key we will look at every single piece of feedback that comes in based off of Scheme-it and all of our tools, and those things can get added to the roadmap,” Sandys says.

Power design contest

Digi-Key is partnering with IDT for its “Power Without Boundaries” design contest for design hobbyists and professionals. After registering with Hackster.io for Phase I, participants pitch their hardware and software plans for a simple and efficient inductive power design in Phase II to become one of 30 winners of an IDT power developer kit, and then build their project with IDT and Scheme-it in Phase III. Especially enthusiastic participants can actually create their PCB in PCBWeb and earn a little extra credit! Be sure to submit your design idea by December 31, 2015; Phase II winners will be announced January 8, 2016. Visit the design contest page for more details and to see the ideas already submitted.

Monique DeVoe, Managing Editor
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