All posts filed under: Technical

The FreeRTOS Tick – Unravel the Mystery to Master the Tick

Over the last few years, I have become a fan of FreeRTOS for a few different reasons: It’s free (though a paid versions allow for some protection) Portable as it abstracts well from the hardware it runs on Provides an easy way to separate sections of code Allows for control of when, and how often, tasks are run It’s the last point that this post will delve into. How does each thread (tasks in FreeRTOS speak) control when they run? It all comes down to the ‘tick,’ the magical trigger that FreeRTOS uses to know when to switch which task is running or give up waiting for a semaphore that will never be given. What Drives the FreeRTOS Tick It all comes from the FreeRTOS Tick – the function that is called at a periodic interval. As we will see below, this tick drives the context switch between tasks. But first, what drives this tick? At the simplest level, the tick is just a timer that has a period set to match the desired tick rate. …

Full-Scale Production – New Product Introduction in Seven Steps

This is the final step in our series on New Product Introduction: Full-Scale Production. If you missed the rest of the series, get caught up in the intro post. So here we are, after months of hard work, trips to the manufacturer, and probably long nights, we are finally at the last stage of New Product Introduction: Full-Scale Production. While it could be argued that at this stage you are no longer in NPI mode, I view the start of scale production as the transition zone. Full-Scale Production It is now time to turn the crank and print the money. This is where the manufacturer is building hundreds or thousands a day to be shipped out to customers. The processes have been worked out, the hardware and firmware bugs have been solved or accepted, and now it’s just copy and paste. Go ahead and pop the champagne and celebrate, this is an exciting milestone, one that many products never achieve. But Now What? But, the work isn’t over here – though many an engineer wished it …

NPI Product Verification Build

Product Verification Build – NPI in Seven Steps

Product Verification is part six of our New Product Introduction series. If you missed the previous posts and want to get caught up, start with the introduction post. At this stage of the New Product Introduction process, your manufacturer has built small, hands-on runs of your product. They have put their best team on the lines, and probably had a high level of oversight at every step. This has made for very expensive units, probably twice as much as you were expecting. But as described in the Design Verification stage, it was all investment in making sure that everything would run smoothly once the crank started turning. Product Verification Build And that cranks is beginning to wind up. The Product Verification build (or just PV) is much like a mini-production run. In fact, the PV is a practice run before releasing the production flood. This means that what you receive from this build is a product that could, in theory, be placed on a store shelf. As we dive in, we will find that while you …

NPI in Seven Steps – Design Verification Run

Design Verification is part five of our New Product Introduction series. If you missed the previous posts and want to get caught up, start with the introduction post. Your team has now received the Engineering Verification units and your manufacturer has completed their test plan to ensure they are building the product correctly. You’re now ready to build millions, right? Now quite. You have a nice prototype that may even look like a product, but you and your manufacturer need to go through a few more steps before reaching full production, well at least if you want to get it right. At this stage of the New Product Introduction, we are going to build what is called the Design Verification build, or just DV. After completing the EV run, your team and your manufacturer probably had a few design changes needed to get the product working right and able to test efficiently. If those changes were significant, you might have had to redo the EV build, but otherwise, the changes get implemented and the DV build …

NPI in Seven Steps – Production Test, FCT and ICT

Production Test Verification is part four of our look at New Product Introduction, if you missed the previous articles, get caught up here. In this post we use the prototypes from the Engineering Verification build to start the production test procedures and fixtures. At this point in our process through the New Product Introduction, we just received our first manufactured boards from the Engineering Verification run and are giddy with excitement I’m sure (or frustrated with hardware bugs!). Your manufacturer is also excited about the boards as well so they can start the next step in the NPI process: designing and producing the Production Verification Test. What is Production Test Verification As we previously hinted at in the Design for Manufacturing and Test phase, the manufacturer has an incentive to make sure every product that goes out their door works to the best of your design. This is where the Production Test Verification comes in. While the EV build isn’t the final product, it still gives the manufacturer something to work with to figure out how …

Engineering Verification

NPI in Seven Steps – Engineering Verification

This is part three of our dive into New Product Introduction, this time with a look at the Engineering Verification stage. If you missed the previous articles, get caught up here. To this point in the New Product Introduction process, you don’t really have much to show for all the hard work. A couple of reports, pretty renderings of the mechanicals, and lots of hand-waving around the prototype. Get ready to change all of that. In fact, get ready to become the most popular team in the company, everybody will soon ‘be in the area.’ Why? Because you are about to get the first prototypes from the manufacturer that almost look like a product. Engineering Verification Run So now that your manufacturer has reviewed the design, helped you make some changes, and gave their best estimate of the final cost, now it’s time to build something to show for all the hard work. The very first build at the manufacturer is the Engineering Verification build or EV. Depending on how much money your company wants to …

Part availability

NPI in Seven Steps – Part Availability

This is part two of our look at New Product Introduction (NPI) where we will look at part availability. If you missed the first articles, get caught up here. In this section, we dive into Part Availability, alternative parts, and lead times. Products need parts. Otherwise, they would just be ideas. But they can’t be just any parts. You’ve carefully engineered the exact parts into the product to make it spectacular. But what happens if those parts don’t exist at production scale, or are so expensive they would double the product cost? You’ve picked the parts that solve the solution. In this section of the NPI process, your manufacturer finds parts that can make the product. Part Availability Analysis It’s important to both your team and the manufacturer to ensure that the product will be able to be built at a very specific cost. To achieve this, they will look over your Bill of Materials and assess each part for its availability and if any is nearing end-of-life. Parts that are hard to find or difficult to …

Design for Manufacturing and Test

NPI in Seven Steps – Design for Manufacturing and Test

This is the first part of our mini-series on New Product Introduction. If you missed the getting started post, read it here. In this post, we will talk about the first step in the NPI process: Design for Manufacturing and Design for Test (DFM and DFT). No one likes broken products. Customers hate them. Engineers scoff at them. Manufacturers don’t get paid. It just sucks when a brand new thing just doesn’t work. This is why, before even building the first one, the Contract Manufacture spends a good deal of time going over the design to make sure they can build it right and that they have a way to test all the functionality before it even leaves their doors. Design for Manufacturing and Design for Test Analysis In this step of the New Product Introduction, the CM does a review of all the files you provided, from schematics to assembly documentation to labels. While PCBs are often a big part of this process due to their complexity, the plastic enclosures and custom metal attachments must also be examined carefully. …

New Product Introduction - Getting Started

New Product Introduction in Seven Steps – The Beginning

This post kicks off a seven part series on New Product Introduction. Here we will be introducing the concepts. How many failed Kickstarters are out there that couldn’t raise enough cash to make their project into a shelf-worthy product? How many more failed to deliver or even went bankrupt right after because they couldn’t afford to build a second round? It’s not just the makers. Even large corporations that attempt to branch out into the hardware space have failed to bring their product to market. For many, the reason is they do not understand, or they misjudge the requirements needed to make a prototype into a ready to ship product. This process to get from mockup to saleable item is called the New Product Introduction. What happens after the prototype Let’s say your company has a cool little prototype that will be a game changer. Your team has proven it can work. The marketing group is so excited that they want to launch it at the next big expo – which is in two months. To …

Advanced Use of the SPI Interface

Advanced Uses of the SPI Interface

The SPI interface has become as ubiquitous in embedded design as the UART or ADC. This is for good reasons as the SPI protocol has a number of great advantages. It is these advantages that we will talk about today and how to best utilize them in your design. Advanced uses of the SPI interface If you are just getting started with the SPI interface, Sparkfun put together a nice intro on SPI or even check out the Wikipedia article on it. Below I have gathered a list of advanced uses of the SPI interface hardware that could either improve SPI communications between your devices or use the hardware in an unusual way – often to provide means to a different protocol not supported by the hardware. Single direction allows for isolation or level shifting In one of my recent designs, I’ve been using a micro that is limited to 2.8v to 3.3v power source but found an extremely low-power, and low-cost sensor that could only run at 1.8v. Because of the single direction of each of …