Starting your own electronic-kit business

Voices: 15 steps to starting your own electronic-kit business is an interesting article. This engineer started her own successful electronics-kit business. Limor Fried has made Adafruit Industries into a successful electronics-kit business. You can too. Based on her own experience, she offers 15 practical steps for engineers who dream of starting their own kit business.


  1. Tomi Engdahl says:

    How littleBits grew from side project to Star Wars

    Like many of the most compelling startups, littleBits began life as a side-hustle — no expectations, no early push for venture capital. Just a bit of tinkering to pass the time.

    “It wasn’t ever meant to be a product or a company. It was just a little project that I was doing. I took it to Maker Fair in 2009,” Bdeir explains, as we sit down in a corner of the company’s spacious Manhattan digs. “It was just me, in a little booth, showing it off to friends, and suddenly hoards of people started coming up and kids starting lining up to play with them. I started to realize there was a real opportunity to inspire kids and empower them to get excited about education.”

    But the startup’s success goes a lot deeper than good timing. Bdeir began tinkering with the company’s modular building blocks a full three years before founding the company in 2011. In their earliest iteration, the “bits” that form the core of the company’s offering were designed for prototyping. In an era when it was becoming increasingly possible to launch a hardware startup from scratch, Bdeir believed she was working on a powerful tool to help inventors bring their visions to life.

  2. Tomi Engdahl says:

    A lifetime designing PCBs: Merging design and fabrication–Merging-design-and-fabrication

    As I should have known, trying to be successful with major responsibilities at two companies was beyond my ability. I have no regrets about diving into the software side; however, the timing wasn’t right.

    Our design team was strong

    I had no worries about their abilities – the company just needed my focus to manage the sales and operations. We also had new design challenges, mostly because circuit boards were getting bigger and denser.

    The business stabilized, and while it wasn’t without the usual problems of a small company

  3. Tomi Engdahl says:

    Erika Earl: Manufacturing Hacks

    Many of us will have casually eyed up the idea of turning a project into a product. Perhaps we’ve considered making a kit from it, or even taking it further into manufacture. But building a single device on the bench is an extremely different matter from having a run of the same devices built by someone else, and in doing so there are a host of pitfalls waiting for the unwary.

    [Erika Earl] is the Director of Hardware Engineering at Slate Digital, and has a lengthy background in the professional audio industry. Her job involves working with her team to bring high-quality electronic products to market that do not have the vast production runs of a major consumer electronic brand, so she has a lot of experience when it comes to turning a hacked-together prototype into a polished final device. Her talk at the 2017 Hackaday Superconference: Manufacturing Hacks: Mistakes Will Move You Forward examined what it takes to go through this process, and brought her special insights on the matter to a Hackaday audience.

    She started her talk by looking at design for manufacture, how while coming up with prototypes is easy, the most successful products are those that have had the ability to manufacture as a consideration from the start of the design process. Starting with the selection of components, carrying through to the prototype stage, and through design reviews before manufacture, everything must be seen through the lens of anyone, anywhere, being able to build it.

    At the selection of components for the Bill of Materials level, she made the point that high quality certified components can be the key to a product’s success or failure, contributing not only to reliability but also to it achieving certification. In her particular field, she often deals with components that can be close enough to the cutting edge to be prototypes in their own right. She mentioned the certification angle in particular in the context of exporting a product, as in that case there is often a need to be able to prove that all components used to meet a particular specification.

    When it comes to the prototype stage, she made the point that documentation is the key.

    The design review should look at everything learned through the prototype stage, and examine everything supplied to the manufacturer to allow them to complete their work.

    After the talk itself as described above there is a Q&A session where she reveals how persistent and cheeky she sometimes has to be to secure sample parts as a small-scale manufacturer and delivers some insights into persuading a manufacturer to produce prototypes at a sensible price.

    Erika Earl : Manufacturing Hacks: Mistakes Will Move You Forward

  4. Tomi Engdahl says:

    Starting a Services Company: 5 More Tips for Ongoing Success

    Here’s what works and what doesn’t work to help manage and grow a successful services business.

    1. Be prepared for legal issues: You will need a good lawyer, at least part time, on a consistent basis. There’s a myriad of legal and evolving issues of importance in a service business, including how one handles non-standard Master Service Agreements, Non-Disclosure Agreements, partnering agreements, sales agreements, etc.

    2. Manage your staff’s billable hours: In the services business, your staff’s time is the “product.” While long term continuous relationships and retainers are ideal, the mix will vary as will project size. At the same time, you want to provide an engaging, safe and secure environment for your staff.

    3. Good communications skills are essential: While every company says it needs staff with good communication skills, in a services business this is more than just idle talk. In most services companies, virtually everyone on your team is “customer facing.”

    4. Your team (even the engineers) need to be salespeople: Among those of us who are engineers, being perceived as a salesperson can be frowned upon. Perhaps some have had bad experiences with salespeople who were disingenuous or lacked knowledge. In a services company, almost every individual has a potential direct impact on customer satisfaction and landing new business.

    5. Promotion and marketing can involve a range of team members – not just your marketing communications staff.

    A services company needs to learn to continually and evolve its processes.

  5. Tomi Engdahl says:

    Mathieu Stephan : The Making of a Secure Open Source Hardware Password Keeper

    Mathieu Stephan is an open source hardware developer, a Tindie seller who always has inventory, a former Hackaday writer, and an awesome all-around guy. One of his biggest projects for the last few years has been the Mooltipass, an offline password keeper built around smart cards and a USB interface. It’s the solution to Post-It notes stuck to your monitor and using the same password for all your accounts around the Internet.

    The Mooltipass is an extremely successful product, and last year Mathieu launched the Mooltipass Mini.

  6. Tomi Engdahl says:

    Avnet guides the way

    Whether you’re a startup or an established OEM, change is necessary for growth and innovation – but it isn’t always easy to adapt to. The good news is that at the same time technology and your company have been changing, so has Avnet.

    Today, we’re the first ever to offer true end-to-end solutions in-house that enable you to take an idea from prototype through to mass production.

  7. Tomi Engdahl says:


    Karatsevidis and the rest of the nine-person Eve team have spent the last few years building the V, a laptop-tablet hybrid in the mold of the Microsoft Surface, working in remarkable concert with a teeming community of users and fans to create the exact product they wanted. All that was left to do was make it, perfectly, tens of thousands of times in a row. Which Karatsevidis learned is harder than it looks.

  8. Tomi Engdahl says:

    Danielle Applestone: Building the Workforce of 2030

    You wake up one morning with The Idea — the one new thing that the world can’t do without. You slave away at it night and day, locked in a garage expending the perspiration that Edison said was 99 percent of your job. You Kickstart, you succeed, you get your prototypes out the door. Orders for the new thing pour in, you get a permanent space in some old factory, and build assembly workstations. You order mountains of parts and arrange them on shiny chrome racks, and you’re ready to go — except for one thing. There’s nobody sitting at those nice new workstations, ready to assemble your product. What’s worse, all your attempts to find qualified people have led nowhere, and you can’t even find someone who knows which end of a soldering iron to hold.

  9. Tomi Engdahl says:

    First Round Capital:
    Survey: for first time more founders say sales leaders, not engineers, are hardest to hire; 53% say investors have more sway in deals, compared to 39% in 2016 — Every year, we survey as many venture-backed startup founders as possible to figure out what it’s like to run a technology company right now.

    State of Startups 2017

  10. Tomi Engdahl says:

    Steven Sinofsky / Learning by Shipping:
    History shows the best time for startups to out-innovate incumbents in tech is when incumbents have achieved extreme product-market-fit and seem unassailable — One of the most interesting challenges in building an enterprise startup is navigating around, through, under, or over the big tech companies.

    Competing with BigCo: 2018 Edition

    One of the most interesting challenges in building an enterprise startup is navigating around, through, under, or over the big tech companies. There’s nothing new about this as doing so goes all the way back to the creation of Silicon Valley and companies like Intel and HP in the shadow of Fairchild, IBM, and GE.

    A fascinating aspect of this is how the strategies or challenges in competing with these mega-incumbents oscillate from the mindset of aiming the forces disruption (perhaps overused and not always viewed positively these days) at them all the way to cozying up at all costs.

    What is the best way to enter the market when the big companies seem so…big as they do today for the first time in a while?

  11. Tomi Engdahl says:

    How Two Guys and an Internet Forum Built a Kickass Computer

    The China trip was only supposed to last 10 days. For Konstantinos Karatsevidis, the 23-year-old CEO of a new gadget maker called Eve, it was just a quick check-in to make sure production was rolling smoothly on his latest product. Karatsevidis and the rest of the nine-person Eve team have spent the last few years building the V, a laptop-tablet hybrid in the mold of the Microsoft Surface, working in remarkable concert with a teeming community of users and fans to create the exact product they wanted. All that was left to do was make it, perfectly, tens of thousands of times in a row. Which Karatsevidis learned is harder than it looks.

    The 10-day trip stretched into a month and a half, during which Karatsevidis changed his flight home to Finland six different times. “I was living in the factory, basically, with the guys from my team,”

    Karatsevidis feels real pressure to get the V done, and get it right. Not just to appease the 4,208 people who backed Eve on Indiegogo more than a year ago, giving the company $1.4 million. Not for everyone else who pre-ordered, and has waited through months-long shipping delays.

    Mostly Karatsevidis feels he owes it to the thousands of members of Eve’s online forum, who spent the last 18 months helping the team conceive of and build this thing. They decided the form factor. They picked most of the specs. They even chose the name. Eve’s product development doubled as a wild experiment in crowd-sourcing, in which Karatsevidis and his team let users design their ideal gadget and entrust Eve to build it. All those users, and some of the biggest players in the PC industry, are watching to see if Eve can turn a seemingly insane idea—asking a bunch of people on the internet for their opinions, and actually listening to them—into a killer product.

    At first, Karatsevidis and Malhonen spent their time crawling Alibaba, looking for tablets they could tweak and sell.

    But they wanted more control and flexibility, and since Karatsevidis knew a bit about manufacturing

    Karatsevidis and Malhonen found a manufacturer at an electronics fair in Shenzhen that had a tablet design ready to go. They changed a couple of parts, named the device the T1, and started selling it on their website for $159 in late 2014. With a little press and some good reviews, Eve was off and running.

    One thing about the T1 bugged Karatsevidis, though: Everyone had all these good ideas about how to make it even better. He’d find suggestions in comments, in forums, and in feedback from buyers. So Karatsevidis decided to steer into the feedback loop, and enlist all these ideas before they even started designing their next product.

    The Eve founders went to Microsoft’s Finland team and asked for help in figuring out how things work. Microsoft directed them to the Hong Kong Electronics Fair

    The guy turned out to be an Intel bigwig, to whom Karatsevidis immediately pitched his idea. He was going to build a laptop-tablet thing, he said, but he was going to crowdsource everything about it. “That’s a bullshit idea,” the guy said, and walked away. A few steps later, he turned around and came back. “No,” he said, “this is the future.” The Intel exec (who Karatsevidis declines to identify) is now a key mentor to Eve, and helped introduce the company to everyone worth knowing in the manufacturing world.

    Over and over, that crowdsourcing pitch got Eve noticed. Microsoft and Intel both wound up investing in the project; even the Finnish government gave Eve a grant.

    The website opened on January 6, 2016. Pretty quickly, users started to introduce themselves

    On January 18, Malhonen wrote a post called “The Project: ‘Pyramid Flipper’—a PC when you need it, a tablet when you like it.” This was what he and Karatsevidis had decided to build next. Why Pyramid Flipper? Because they wanted to invert the way things were normally done, putting users at the top and corporate bullshit at the bottom.

    The community won arguments with the Eve founders, making clear that pen support mattered when Karatsevidis didn’t think so.

    In every discussion, a few familiar tropes emerged. Somebody always wanted something impossible, like months-long battery life. Somebody would try and make everything about their specific needs. Somebody always just wanted to tell everyone else they sucked. But in every case, sanity prevailed. And the community, growing all the time, dreamed up a shockingly reasonable device. The Pyramid Flipper they imagined shared a lot in common with the Microsoft Surface, only with better battery (and a slightly bulkier body), more ports, and a more efficient processor. When it came time to name the thing, the place almost ate itself alive.

    Once they’d finalized the basic specs and design, Karatsevidis and Malhonen built the prototype of the V. Once that came back, and they were confident this thing was going to work, they launched the Indiegogo campaign in November of 2016. “The idea behind Indiegogo was that none of your money is used for development,” Karatsevidis says. They’d paid for that with help from their partners and the leftover T1 profit.

    The campaign was a huge success—it hit its goal in four minutes—to a degree that worried the Eve founders.

    By the end of the campaign, Eve had thousands of orders to fill, $1.4 million to spend, and nearly 3,000 people in its community.

    “We were like, ‘OK guys, that’s it. Indiegogo’s successful, we’ve finished development, we’re ready to ship! That’s it.’”

    A few weeks later, Karatsevidis recanted in a long post in the Eve forums. “This week has been a long one,” he began, before detailing the problem they were having with the V’s screen supplier. They’d pre-ordered 15,000 displays, paid in cash, and the screens that came in were straight-up terrible. They had yellow stains, dead pixels, light bleed everywhere. “Fortunately, our screen supplier has stock and they will send us new screens already next week,” he wrote. Except the next batch, which took a month to arrive, came back the same way. Ditto the next batch. Eve couldn’t switch suppliers, since this one already had their money, and nobody else made the screen they needed.

    Eventually Eve found a new display supplier, they got everything swapped in, and by October had entered into full mass production.

    After all the debates and polls, you’d think the Eve V would be the sort of too-many-cooks device that everyone built and nobody likes. A camel is just a horse designed by committee, after all. But somehow, against all odds, Eve made a terrific device. Sure, the final V has a couple of quirks, like a backspace key marked “Oops!” and a design that won’t exactly wow a Best Buy shopper, but it’s a shockingly impressive device.

  12. Tomi Engdahl says:

    10 Crowdfunded Technology Wonders You Didn’t Know You Wanted

    Today, with the help of the masses, high-tech and electronics product designers can test their ideas and get funding for their crazy and creative ideas. Scrolling through the top crowdfunding sites shows some interesting examples of products that no one knows they need, but now everyone wants.

    Crowdfunding is a craze that only seems to be growing, and that will continue to grow for the foreseeable future. Crowdfunding of products (as opposed to equity or lending crowdfunding offerings) accounted for $919 million in transactions in the United States alone in 2017, according to Statistica. Meanwhile, worldwide transactions will account for $9.4 billion this year, the company predicted. Over the next five years, the market is expected to grow by a compound annual growth rate (CAGR) of 11% in the United States to reach $1.5 billion by 2022 and 29% CAGR worldwide in the same period.

    The draw of crowdfunding for product innovators is easy to understand. Funding can be figured out quickly, in days or months rather than years. Meanwhile, those who are often underserved by venture capitalists, such as woman- and minority-owned businesses, enjoy a much more level playing field. It also provides built in market research so that those that get the votes have a clear path to a successful product launch.

  13. Tomi Engdahl says:

    Jonathan Shieber / TechCrunch:
    GE Appliances, a subsidiary of China’s Haier, is spinning out Giddy, its Quirky-like crowdsourced hardware product development platform for businesses

    GE Appliances is launching its own version of Quirky for businesses called Giddy

    GE Appliances (now a subsidiary of the Chinese appliance manufacturer Haier) is spinning out a crowd-sourced product development business as a service for corporate customers under the name Giddy.

    It’s the idea that won’t die — even though several of the companies that originally supported it have foundered over the years. Companies like Quirky and Local Motors tried to tap the maker community to create product development shops that would leverage amateur engineering and design talent and at-home prototyping to create new products to sell to the mass market.

    Those companies raised more than $100 million dollars in combined financing to pursue their vision, but Quirky went out of business and Local Motors has seen its vision for letting 1,000 car designing engineers flourish stall out.

    Now GE Appliances, which once celebrated its Quirky connection, is taking the same model and pitching it to other corporations.

    From its headquarters in Louisville, Kentucky, GE Appliances had incorporated the Quirky model as a subsidiary called FirstBuild, which the company was using to test new products. Some of those products, like a new ice maker and machine for cold-brewing coffee, have had success and actually made it to market.

    “Companies are continuing to evolve the way they approach innovation, and are more willing to go outside their four walls to generate good ideas,”

  14. Tomi Engdahl says:

    Graphene Research Targets Wireless Sensors for IoT

    Judging by the popularity of “How It’s Made” and other shows of the genre, watching stuff being made is a real crowd pleaser. [Jonathan Oxer] from SuperHouse is not immune to the charms of a factory tour, so he went all the way to China to visit the factory where Sonoff IoT devices are made, and his video reveals a lot about the state of electronics manufacturing.

    #27: Visit to the Sonoff factory and ITEAD

    UPDATE: I’ve been asked by several people how they can get in touch with factories so they can go on tours. Please DON’T DO THIS unless you are serious about doing business with that company. Factories are not amusement parks, and the staff who work in them are busy doing their jobs. If you want to manufacture a product and you seriously want to do business with a factory, then it’s easy to arrange a tour. But don’t do it just because you want to have a look! That wastes their time.

  15. Tomi Engdahl says:

    David Pierce / Wired:
    Profile of Google’s SVP of hardware Rick Osterloh, who restructured its hardware organization and is tasked with integrating Google Assistant into devices

    One Man’s Quest to Make Google’s Gadgets Great

    Google is leaning on Rick Osterloh to completely rewrite its strategy for hardware, with one core goal: Put its virtual assistant everywhere in people’s lives.

    Osterloh wasn’t hired to dream up new products. He was brought in to teach a software company how to endure the long, messy, totally necessary process of building gadgets and to change the company’s culture from the inside. It’s not enough to have great software and the industry’s finest collection of artificial intelligence researchers. To take on Apple, Google had to finally learn how to build good hardware.

    The man in charge of Google’s hardware renaissance has always had a weakness for gadgets.

    Google’s relationship with hardware has always been awkward. Most of the company’s physical products are born the same way: Someone has a great idea for software, but they can’t find the right gear on which to run it. That person then sets out to build the missing gadget with very little help. Google tends to treat these products as reference devices or sources of inspiration, proving that an idea can work and hoping an ecosystem of hardware makers takes it from there. As a result, Google’s list of orphaned products and abandoned ideas—from the Chromebox to the Nexus Q to the Nexus Player—is enough to fill a Circuit City.

    That’s no surprise: Making hardware runs counter to Google’s entire corporate culture. The company shuns process and management, two things a hardware maker can’t do without. In its software development, Google actually encourages and applauds chaos, inviting anyone at the company to just build something and see if it works.

    The company’s most successful products are subject to constant refinement. Former CEO Eric Schmidt calls this system “Ship and Iterate,”

    Ship and Iterate simply doesn’t work with hardware. A single tweak can cost weeks and millions of dollars. Every small change ripples through the entire supply chain, changing vendor timelines, requiring new tools, and slowing everything down. If one part is late, you’ll miss your ship date, and it’s not like you can move Black Friday. Oh, you want 50 percent more product than you thought? You’ll get it in six months if you’re lucky. There is no bending the hardware world to your whim.

    Even when hardware development was going well, company culture didn’t support those teams in getting the software they needed. “We had to go beg and plead to make all the software teams care,”

    At Google, the culture revolves around software. That’s what it’s best at and where it makes its billions. With its push for a virtual assistant, that ethos was no different. Except that this time the stakes seemed much higher.

    Pichai was certain that this helpful chatterbot would be the way billions of people interacted with Google in the future. Done right, Assistant could be an omnipresent artificial being

    When Google had built hardware in the past, it had done so through partnerships with seasoned manufacturers. But its relationships with its Android partners were souring. Samsung, Android’s most important partner, was developing its own virtual assistant, Bixby, and distancing itself from the Mountain View giant. Google couldn’t even rely on its traditional Nexus program

    Unfortunately, Google had already divested itself of its own hardware expertise, selling Motorola to Lenovo in 2014 for about $3 billion. Nest, its other giant hardware acquisition, had lost its founder and was embroiled in management and product turmoil.

    He told Osterloh that Pichai was looking to start a hardware group and wanted some advice. Just advice, nothing else.

    Osterloh’s meeting with Pichai quickly turned into a job interview, with lots of questions on both sides. In many hours over a few days, Osterloh realized Pichai was actually, finally, talking about his dream job.

    Osterloh centralized all that hardware under his leadership, giving 55 percent of those 1,000 employees a new manager.

    Part of the impetus for Osterloh’s new structure was to make sure nobody felt like their job was tied to one product, so they wouldn’t panic if that product were killed. Because Osterloh needed to kill some products.

    He went through every hardware initiative at Google, choosing which to continue and which to wind down.

    He had to embrace the fact that even as Google gets serious about gadgets, the company’s focus is, and always will be, elsewhere.

    For the new hardware team, the task was clear: Find more ways to get Google Assistant in front of people and build a sustainable business around it. Oh, and hurry, because Google is already behind, with Siri and Alexa already entrenched in consumers’ minds.

    Designing hardware and software in tandem allows for the detailed decision-making that makes people fall in love with their phones.

    With the employees of the hardware division settled into their new roles, Osterloh and his team started working out their production needs. He and Corrales toured manufacturers in Asia, telling them what Google was up to and how they’d be interacting going forward, and they brokered new deals with suppliers. In November 2017, Osterloh oversaw the $1.1 billion acquisition of an HTC division that brought more than 2,000 engineers to Google,

    There’s plenty of reason to rush. Apple and Samsung continue to push new competitive software onto their hardware, and new classes of devices are getting better all the time.

    At every turn, rather than tout spec sheets, Osterloh explains how artificial intelligence can extract remarkable experiences from ordinary hardware.

    All these issues make Osterloh angry—“I lose sleep every time customers aren’t happy,” he says—but they seem to energize him as well. He knows how to handle these kinds of challenges: more rigorous process, tighter management. It’s typical hardware stuff, lessons he learned long ago.

  16. Tomi Engdahl says:

    Prototype to production: Building your first PCB prototype (part 1)

    kick off a three part blog series about building your first PCB prototype. PCBs (printed circuit boards) are the heart and brains of every product that turns on, plugs in, or lights up.

  17. Tomi Engdahl says:

    Power Management, Chapter 3: Power Supplies-Make or Buy?

    Power supplies are necessary in virtually every piece of electronic equipment. Therefore, equipment manufacturers are confronted with the task of deciding whether to make or buy a power supply for their system. DC power management employs a power supply that can either be bought or made by the equipment manufacturer. The make-or-buy decision for power supplies can have a major impact on the cost and time-to-market for the end-item electronic equipment.

    The equipment manufacturer has several challenges to consider before making a power supply in-house:

    • Can they make it cheaper than a purchased power supply?

    • Is time-to-market a consideration?

    • Are the necessary people and resources available to make the power supplies, including design and production facilities?

    • Does the design and production include the time, costs, and fees associated with getting agency certifications specific to power supplies?

    Unless the equipment manufacturer can meet these challenges, it most likely will buy the power supplies and then implement the power management subsystem.

  18. Tomi Engdahl says:

    Smart Outlet Cover Offers Lessons on Going from Project to Product

    Going from idea to one-off widget is one thing; engineering the widget into a marketable product is quite another. So sometimes it’s instructive to take an in-depth look at a project that was designed from the get-go to be a consumer product, like this power indicating wall outlet cover plate. The fact that it’s a pretty cool project helps too.

    Although [Vitaliy] has been working on this project for a while, he only recently tipped us off to it, and we’re glad he did because there’s a lot to learn here. His goal was to build a replacement cover for a standard North American power outlet that indicates how much power is being used by whatever is plugged into it.

    Energy and power indication inside the space of standard outlet cover

    Main Function
    Provide non intrusive way to sense total outlet current and process it for visual indication of:
    power usage and energy usage (this prototype measured apparent power rather than real power)

    Relative accuracy throughout the large range of measurements from ~21mA which is about 2.5W smallest cell phone charger to 13A or 1560W aprox max allowed power draw from outlet.

    IoT connectivity and data processing
    This was not implemented in this version but something I was thinking of in the future if prototype worked. There’re lots low cost, IoT MCUs on the market today that can be used for this purpose. But the first objective was to see if reliable sensing will be possible.

    Taking apart one of the outlets to see where the best, non intrusive place to sense the current could be, I noticed that the center mounting bracket is ferromagnetic in nature and serves as a conductor (concentrator) of the magnetic flux flowing through the center of the two prongs of the plugs when current flows. As long as this magnetic circuit is not short circuited during installation it could be used for sensing.

    One idea was to build a the current transformer using the plug’s prongs as a single loop primary and using mounting bracket as a magnetic core.

    However, that idea was short lived. The number of turns of the primary coil needed was making the coil too large even with the smallest wire diameter.

    The least cost in parts, assembly labor and size seem to be placing two small magnetic pick up coils positioned at the opposite sides of the center mounting bracket to pick up the magnetic field generated from the current in the plug(s). The small profile, high inductance, off the shelf coils are also readily available.

    Symmetrical positioning of sensors allowed consistency in current measurement from upper and lower outlet.

    The coils used were off the shelf throughole parts, 100mH each, B82144A2107J.

    Some specs for the power supply: to drop down the AC line voltage to the 3.3V to power circuits, has to be small enough to fit into thin space, safe enough not to overheat or start fire especially in the event of voltage spikes or lighting transients and component failures, be reliable enough to supply fixed and clean voltage to the sensitive circuits like microcountroller. Power supply must also be of little cost, which relates to simplicity.

    ATMEGA328PB is a low cost 8 bit, 16Mhz processor that has all the core functions needed for this design with 8 multiplexed 10 bits ADC inputs. The very first prototype I had was done using Arduino Mini that uses this processor. In order to drop the power usage to minimum the processor speed is set at 8 Mhz max speed (~38% less power than 16Mhz) it was more than enough to do the job. All other processor internal modules were shut off to save power.


    The software IDE I used was MisualMicro plugin for the MS Visual Studio. It’s free to use and has much better environment for codding than arduino IDE. Microprocessor performs all the work in sampling, converting and displaying power/energy usage. In first version of software, processor measures the apparent power by simply computing RMS of the current and multiplying it by RMS of the voltage (fixed constant).

    Manufacturing Cost Estimates

    The goal was to try to find most “bare bones” design that will adequately satisfy the requirements at the lowest component cost and count. With the current design there’s still room to reduce the cost by for example getting rid of crystal (~$0.71) and by using internal RC for clock generation, although with degradation in timing accuracy.

    PWB assembly only:
    Component BOM cost (based on digikey/mouser pricing): $10.1/ea Qnty 1000 (~$21 Qnty 10)
    Bare PWB cost: <$0.20/ea Qnty 1000
    Assembly of PWB cost: $1.3/ea Qnty 1000
    TOTAL: $11.6/CCA

    Mechanical assembly (qnty 1000):
    Outlet plastic cover injection molded with holes and studs for CCA mount: $0.80
    Contacts and misc assemlyl parts: $0.10
    TOTAL: $0.9/Parts

    Known problems

    One major limitation of this sensing approach is that since magnetic circuit is not closed, it's naturally will be susceptible to external interference. In this case the accuracy seem to suffer if the outlet is not the last on the wiring branch.

    The sensors, even positioned to sense magnetic flux deferentially, are still appear to be susceptible to the stray fields to the point where reading are off by more than 30% depending on the current even more

    The other limitation is the interference caused by "wall wart" type of adapters (e.g. cell phone chargers).

  19. Tomi Engdahl says:

    Taking a Guitar Pedal From Concept Into Production

    Starting a new project is fun, and often involves great times spent playing with breadboards and protoboards, and doing whatever it takes to get things working. It can often seem like a huge time investment just getting a project to that functional point. But what if you want to take it to the next level, and take your project from a prototype to a production-ready form? This is the story of how I achieved just that with the Grav-A distortion pedal.

    Why build a pedal, anyway?

    A long time ago, I found myself faced with a choice. With graduation looming on the horizon, I needed to decide what I was going to do with my life once my engineering degree was squared away. At the time, the idea of walking straight into a 9-5 wasn’t particularly attractive, and I felt like getting back into a band and playing shows again. However, I worried about the impact an extended break would have on my potential career. It was then that I came up with a solution. I would start my own electronics company, making products for musicians.

    I Love It When A Design Comes Together

    From Prototype to Production

    The prototype was great and was serving me well on stage, but was too time consuming to build and more fragile than I liked. Particularly egregious was the DC power jack, which didn’t quite fit into the custom machined enclosures. While I enjoyed the pedal and got great feedback from friends, it wasn’t something I could put on the market in its current state, with parts that didn’t quite fit right and artwork that wasn’t dead-on. Another issue was that the the original op-amp I’d used, the LM301, was no longer in production. I resolved to tweak these issues as I moved closer to release.

    As far as the DC power jack was concerned, I decided to switch to a case-mounted jack,


    Having pre-orders for the pedal meant there was a time pressure on getting them out the door, which meant I was thrown headlong into the organised chaos that is production. There were lessons that were learned that I hadn’t even remotely expected.

    The biggest issue as production ramped up was cosmetic damage. When you’re selling a boutique item for over $150, people expect to receive it in good condition. Having grown up doing projects for myself in my parent’s workshop, my working methods were rough and ready. It was all too easy to drop a tool onto an enclosure or drop a unit on the ground, creating dents, scratches, or paint chips, ruining the finished product. I attempted the dreaded task of reworking these blemished cases, but bar a couple of lucky successes, it was all for nought. This was a huge problem as the cases were costing well over $25 each by the time shipping was accounted for. After dealing with this problem too many times, I revamped my work station, putting down soft foam and organising my tools carefully to avoid inadvertently marring the cases. Simply taking some care in the set up of my work area proved invaluable in reducing these issues.

    Beyond that, shipping was a huge problem.

    other boutique pedal manufacturers based in countries like the US which had much cheaper access to components and enclosures.

    How The Story Ends

    Eventually, it became clear that selling a distortion pedal built in one of the farther flung reaches of the earth was going be a difficult prospect to maintain. It’s certainly not impossible, but the guitar pedal market is flooded with thousands upon thousands of distortion pedals, and thus it is hard to stand out from the crowd.

    After fulfilling preorders and wrapping up the second major production run, it became clear that the pedal wasn’t generating a significant amount of profit for the time invested. I slowly began to sell down the last of my stock while developing a second product aimed at a different market.

    A Passive Mixer’s Adventure Through Product Development

  20. Tomi Engdahl says:

    The Future of Manufacturing and Hardware is Happening Today — in Shenzhen

    If you are in hardware, all roads lead to Shenzhen.

    In the US, we lament about how it’s hard to back hardware startups; it’s not uncommon to hear VC’s exclaim, “we don’t do hardware.” This is because an overwhelming majority of hardware startups take much longer and end up requiring much more capital to come to fruition than what entrepreneurs or investors would expect. Hardware startups are costlier on every dimension — building a prototype, setting up manufacturing, fixing quality issues, or iterating on product.

  21. Tomi Engdahl says:

    The useful resource makers can’t miss

    With years of experience in open source hardware industry and located in Shenzhen which is referred as the largest electronic market of China, Elecrow has developed a mature supply chain in PCB service and wins a good reputation in international electronics hardware communities. Due to the continuous research and concentration on the needs of industry and individual maker, engineer and entrepreneur, Elecrow got down to expand the production lines in 2017 and launched the brand new one-stop solution to hardware project in March, 2018, to be an accessible and cost-effective manufacturing resource for everybody who has ideas to create electronic hardware.

  22. Tomi Engdahl says:

    Avnet, Kickstarter, and the Hardware Studio Program

    Bob Merriman introduces Hardware Studio Connection, a new application-based program for hardware creators.

  23. Tomi Engdahl says:

    Hassle Free Shipping: Now Serving with Incoterms DDP

    Arrow now offers Delivered Duty Paid DDP. This new feature allows you to focus on designing and building, while we handle all the paperwork.

    What is Delivered Duty Paid DDP?

    Delivered Duty Paid DDP is a delivery agreement where the seller assumes all risk, responsibility, and costs associated with good transport until they are received or transferred by the buyer.

    This means:

    – You place the order, and we handle the shipping arrangements from our warehouse to your shipping address.
    – No need to clear the goods for transport – we take care of that for you.
    – We clear the items for import and cover all the costs and procedures.
    – The responsibility is ours if items in your order are lost or damaged during transport.
    – All costs associated with taxes, customs, and export licenses are covered by Arrow.

  24. Tomi Engdahl says:

    How to Build a PCB: Through-Hole or Surface-Mount?

    Should folks building small numbers of circuit boards use surface-mount parts, or should they stick with through-hole components that are so much easier to handle and solder (not to mention see)?

    If you’re ever planning on building in volume, starting with surface-mount is the way to go. This way, you won’t need to redesign your board between your prototypes and production. This can be a big time and money saver.

    The big question, however, is cost. Doesn’t it cost a lot more to use surface-mount because you need to contract out the assembly work? Well, anytime someone is doing work for you, it’s going to cost money, but the equation is a little more complex than that.

    Most people, with some patience, a good magnifier (or high-power reading glasses), and something to rest a wrist on, can hand-solder down to 0603 or 0402 packaged passive parts. Some people have even figured out how to hand-solder QFNs and BGAs. Below a certain point, however, hand work just isn’t practical without specialized equipment (it can be done, though).

    If you are working on a hobby project, you’ll need to stick to things you can hand-solder yourself, get a toaster oven set up, or find a shop that caters to low-cost rather than high reliability. When what you are doing starts to become a business, then time equals money, at which point you can trade the two factors off depending on your needs.

    The bottom line is that, if you prefer through-hole parts, then by all means use them. There’s no shame in it. Just understand that some of the newest and most capable parts may not be available to you. I personally recommend using surface-mount parts whenever possible.

  25. Tomi Engdahl says:

    Field Trip! Hackaday Visits Pimoroni

    If you have a Raspberry Pi and have any interest in its peripherals, you may be familiar with the grinning pirate logo of the British company, Pimoroni. The Sheffield, UK based outfit first established a niche for itself as one of the go-to places for much of the essentials of Pi ownership, and has extended its portfolio beyond the Pi into parts, boards, and components across the spectrum of electronic experimentation. Their products are notable for their distinctive and colourful design language as well as their constant exploration of new ideas, and they have rapidly become one of those companies to watch in our sphere.

  26. solar charger 24000mah says:

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    of plagorism ᧐r copyгight violation? Ꮇy websijte һas a lot of uniqu ϲontent I’ve eitһer authored myself orr outsourced
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    • Tomi Engdahl says:

      Pretty much all the methods that try to stop the content from being stolen effectively make accessing the content in the first place harder and more frustrating to users. Basically if it can be viewed, it can be copied in a way or another.

  27. Tomi Engdahl says:

    How to Build a PCB: Panelization: What is it and Why?

    If you have a lot of boards, or if your boards are very small, then you probably want them to be in a panel.

    If you typically just build one or two copies of a printed circuit board (PCB), or if your only experience with them is buying a pre-built board, you may not be familiar with the concept of panelization. For high-volume manufacturing, blank printed circuit boards are built in large panels — also called “arrays” or “palettes” — of multiple boards.

    essentially — that’s the standard way of building a large quantity of boards, and it has been for decades. Oftentimes, that large panel will be cut into quarters to better fit assembly machines before being sent out for assembly.

    In a standard panel, each copy of the board will be exactly the same. There are some cases, though, where the boards will be different. Some designs require a set of several different circuit boards. In what’s called a “family panel,” all of the different boards are combined into one panel.

    Prior to shipping, each board would be cut out with a router. Today, this is referred to as “individually routed.” It delivers a nice smooth edge with none of the little “nibs” protruding that you see on many boards that came out of a panel. It’s a very cost-effective way to purchase a small number of blank PC boards.

  28. Tomi Engdahl says:

    Field Trip! Hackaday Visits Pimoroni

    If you have a Raspberry Pi and have any interest in its peripherals, you may be familiar with the grinning pirate logo of the British company, Pimoroni. The Sheffield, UK based outfit first established a niche for itself as one of the go-to places for much of the essentials of Pi ownership, and has extended its portfolio beyond the Pi into parts, boards, and components across the spectrum of electronic experimentation.

  29. Tomi Engdahl says:

    5 Things to Do When Launching an Engineering Startup

    The freedom that comes with being your own boss can’t be beat: You make your hours, find your clients and reap the financial benefits. However, the reality looks more like working all hours, babysitting clients and haggling for payment.

    Pitch Perfect
    Write Your Plan
    Understand Your Limitations
    Line Up Funding
    Don’t Settle

    All your tools — whether of hardware, software or human capital — should be the best. The challenge you likely face is having a limited budget, so you have to make the most of it.


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