We check out this cool kit from Nordic: a multi-sensor cellular IoT prototyping platform for hardware engineers. Easily connect Arduino shields and standalone sensors to the nRF Connect for Cloud platform (nrfcloud.com).
Where the Thingy:91 device (previously: https://www.youtube.com/watch?v=tLUKgDT2V9g) comes with built-in sensors and a consumer-ready interface, the nRF9160 DK empowers you to prototype apps with your own custom hardware.
This useful SHIM ("shove hardware in the middle" device) provides active cooling for your Raspberry Pi! While updates to the firmware mean that you no longer *need* cooling (unless you’re trying to overclock your Pi), a little fresh air never hurts. We put together this "whisper-quiet" little peripheral in a couple of minutes, no fuss.
All aboard for Hackster Launch – our collaboration with GroupGets, bringing you fresh hardware and new audiences. See below for a Pi Zero-shaped Arduino, a PC-friendly Click board interface, and more!
Plus, take a look at the UNDP Covid-19 Detect & Protect Challenge grand prize winners, and sign up for our other ongoing contests before they close!
Researchers have developed new software that can be integrated with existing hardware to enable people using robotic prosthetics or exoskeletons to walk in a safer, more natural manner on different types of terrain. The new framework incorporates computer vision into prosthetic leg control, and includes robust artificial intelligence (AI) algorithms that allow the software to better account for uncertainty.
“Lower-limb robotic prosthetics need to execute different behaviors based on the terrain users are walking on,” says Edgar Lobaton, co-author of a paper on the work and an associate professor of electrical and computer engineering at North Carolina State University. “The framework we’ve created allows the AI in robotic prostheses to predict the type of terrain users will be stepping on, quantify the uncertainties associated with that prediction, and then incorporate that uncertainty into its decision-making.”
The researchers focused on distinguishing between six different terrains that require adjustments in a robotic prosthetic’s behavior: tile, brick, concrete, grass, “upstairs” and “downstairs.”
“If the degree of uncertainty is too high, the AI isn’t forced to make a questionable decision — it could instead notify the user that it doesn’t have enough confidence in its prediction to act, or it could default to a ‘safe’ mode,” says Boxuan Zhong, lead author of the paper and a recent Ph.D. graduate from NC State.
The new “environmental context” framework incorporates both hardware and software elements. The researchers designed the framework for use with any lower-limb robotic exoskeleton or robotic prosthetic device, but with one additional piece of hardware: a camera. In their study, the researchers used cameras worn on eyeglasses and cameras mounted on the lower-limb prosthesis itself. The researchers evaluated how the AI was able to make use of computer vision data from both types of camera, separately and when used together.
“Incorporating computer vision into control software for wearable robotics is an exciting new area of research,” says Helen Huang, a co-author of the paper. “We found that using both cameras worked well, but required a great deal of computing power and may be cost prohibitive. However, we also found that using only the camera mounted on the lower limb worked pretty well — particularly for near-term predictions, such as what the terrain would be like for the next step or two.” Huang is the Jackson Family Distinguished Professor of Biomedical Engineering in the Joint Department of Biomedical Engineering at NC State and the University of North Carolina at Chapel Hill.
The most significant advance, however, is to the AI itself.
“We came up with a better way to teach deep-learning systems how to evaluate and quantify uncertainty in a way that allows the system to incorporate uncertainty into its decision making,” Lobaton says. “This is certainly relevant for robotic prosthetics, but our work here could be applied to any type of deep-learning system.”
To train the AI system, researchers connected the cameras to able-bodied individuals, who then walked through a variety of indoor and outdoor environments. The researchers then did a proof-of-concept evaluation by having a person with lower-limb amputation wear the cameras while traversing the same environments.
“We found that the model can be appropriately transferred so the system can operate with subjects from different populations,” Lobaton says. “That means that the AI worked well even thought it was trained by one group of people and used by somebody different.”
However, the new framework has not yet been tested in a robotic device.
“We are excited to incorporate the framework into the control system for working robotic prosthetics — that’s the next step,” Huang says.
“And we’re also planning to work on ways to make the system more efficient, in terms of requiring less visual data input and less data processing,” says Zhong.
Help solve the symptoms of menopause, and you could win thousands of dollars and mentorship in our new hardware design contest! Do you already have a biotech project that would fit the challenge? Submissions are open until April 12th.
New hardware from SparkFun! These RED-V boards pack all the power of the open source SiFive FE310 chip, along with Qwiic connectors and more, in a low-cost package. They’re also compatible with Arduino and Adafruit Feather platforms. Sweet!
This edition of the 3D Printing Industry’s news digest, Sliced, sees a variety of hardware and material releases from Dyze Design, 3D Systems, colorFabb, and EOS, as well as new 3D printing applications in brewing and underwater drones. All this and more from GE Additive, The Toro Company, Delft University of Technology, Jaguar Land Rover, Additive Manufacturing Technologies, and Singapore University […]
Azure Sphere provides more than just a hardware and software platform for building Internet of Things (IoT) solutions. The third component to the mix is the cloud services that Microsoft offers as part of the Azure Sphere platform. The Azure Sphere Security Service (also referred to as AS3) is the cloud component Microsoft offers for integrating the full circle of IoT security in the Azure Sphere platform. This provides an integration of hardware microcontroller (MCU), a Microsoft customized Linux operating system, and the cloud based Azure Sphere Security Service to provide a platform for building more highly secured IoT solutions.
The Azure Sphere Security Service provides services like remote attestation to authenticate the device and ensure it hasn’t been tampered with, and securely pushing down Azure Sphere OS and other software updates to Azure Sphere devices.
The Microsoft Azure Sphere Security Service (AS3) is a trusted authority for all Azure Sphere devices. The AS3 service provides services like remote attestation to authenticate the device and ensure it hasn’t been tampered with, and securely pushing down Azure Sphere operating system (OS) and other software updates to Azure Sphere devices. The Azure Sphere device connects to the AS3 service to authorize the device and ensure that only an authorized version of genuine, approved software runs on the device. By integrating with the AS3 service, the Azure Sphere device will automatically download and install OS updates without any action required on the part of either the device manufacturer or the end-user of the device.
The above diagram shows the overall architecture and role that the Azure Sphere Security Service plays within a larger IoT scenario that you might be building and deploying with hundreds, thousands, or even millions of Azure Sphere devices.
Here’s the description of the different pieces and numbered steps of the scenario outlined in the diagram:
Microsoft releases an update to the Azure Sphere OS and publishes it through the Azure Sphere Security Service. This enables the update to be available for all Azure Sphere devices, across all customers using Azure Sphere.
Your product engineering team releases a software update for your DW100 product built with Azure Sphere. The software update is released to the Azure Sphere Security Service so auto-update and deployment to all your deployed devices can be performed.
The Azure Sphere Security Service communicates securely with devices and deploys both the Azure Sphere OS and your engineering team’s software updates to the Azure Sphere devices. These devices could be running at your company locations, or at customer sites anywhere in the world where they have an Internet connection to receive the updates and communicate with the Azure Sphere Security Service.
Your product support team can communicate with the Azure Sphere Security Service to monitor which version of the Azure Sphere OS and your engineering team’s software should be running on reach of the products built with Azure Sphere.
Your product support team can also communicate with the other enterprise cloud services that the IoT solution is built with; along with your Azure Sphere devices communicating with those cloud services as you’ve built them to as part of the IoT solution.
The Azure Sphere devices (wherever they are in the world) will download the Azure Sphere OS update, and the update for your engineering team’s software using the connection to the Azure Sphere Security Service. These devices will also be communicating with any other cloud services that comprise the overall IoT solution.
All communications with the Azure Sphere Security Service (AS3) takes place over secured, authenticated connections. The engineering team pushing out software updates will need to authenticate and communicate securely with the Azure Sphere Security Service when rolling out new software updates to deploy to devices. The Azure Sphere devices on the receiving end of these updates, will also communicate securely in a “per-device authentication” model to ensure that only authorized devices are able to communicate with AS3 and they receive the correct software updates.
All communications with the Azure Sphere Security Service takes place over secured, authenticated connections.
In addition to the secure communication methods with Azure Sphere Security Service, the Azure Sphere devices are only able to run authorized software. This is done by the security measures built into the Azure Sphere OS, along with the Azure Sphere Security Service, are setup to only allow cryptographically signed and verified software updates to be installed on Azure Sphere devices.
The features of providing certificate-based authentication and secure software update deployment to Azure Sphere devices are the two primary features of the Azure Sphere Security Service. Monitoring and failure reporting features are also very useful features of the service. These features enable the other features to function, as it’s important to know which software updates were successfully deployed to devices. It’s also important to know about crash reports of deployed software updates as well.
Hopefully, this article provided you with a better understanding and explanation of what the Azure Sphere Security Service is, and what role it plays in building more highly secured IoT solutions. Building highly secure IoT solutions is very important, and Azure Sphere provides hardware, software, and cloud components to help make this a more easily achievable task for any IoT engineering team building the next great IoT product.
In my years of working with hardware entrepreneurs I’ve seen too many cases of poorly designed Printed Circuit Boards (PCB) that would never be of sufficient quality for commercial production.
In some cases these boards were designed by the entrepreneur themselves, and other times they were designed by a freelance engineer.
Especially, in cases where you are paying a supposed expert to design your PCB, it’s important that you are able to judge the quality of their work.
As I think many electrical engineers will agree, most engineers are never taught PCB design in school, so you need to be careful that you don’t hire an engineer lacking real-world PCB design experience.
Although it really takes an expert in PCB design to do a proper full design review, there are ways to quickly judge the quality of a PCB design.
NOTE: This is a long, very detailed article so here’s a free PDF version of it for easy reading and future reference.
A schematic may tell you how the individual components are to be connected together to provide a given functionality. However, in and of itself, it offers very limited information about how to actually place, and connect, the components together to provide a functional product.
For example, schematic lines translate to traces on the Printed Circuit Board (PCB). But, the schematic provides little to no information about the kind of signal these lines carry, unless it is explicitly documented in the schematic.
This schematic documentation is especially critical if a different engineer designs the PCB layout than the engineer that designed the schematic.
The signals in those lines could be low-level, low-noise signals that have to be routed away from more noisy PCB traces to avoid noise pickup.
Or, they could be fast data or clock signals that fan out to many pins on multiple chips. In this case, the traces should be matched in length, and be kept short, to avoid mismatched delays.
If such traces are not properly designed, some of the PCB’s might work and some might not, depending on the characteristics and tolerances of the components used to populate each PCB.
In other words, even if a PCB faithfully implements all the component interconnections of a fully working schematic, the end product might not work as intended, if at all.
This article presents 7 ways of quickly judging the quality of your PCB design.
The focus here is on the layout and component placement, rather than the actual quality of the board construction itself (which is solely dependent on the board manufacturer).
Finally, this article is not intended to be highly technical, and certainly does not cover all possibilities, especially for highly complex designs, or designs having unique requirements.
The goal of this article is to show you how to quickly determine if you have a poor PCB design, since there are a few specific areas of PCB design which new designers are most likely to do incorrectly.
Take an overall look at the visible traces on the PCB. These will be covered by a solder mask, which is a thin lacquer-like layer of polymer that covers the copper traces to prevent oxidation and shorts.
This layer is usually green, but other colors are also available. Note that white solder mask tends to make the traces the most difficult to see. In most cases, just go with the standard green.
Also, only the top and bottom layers are actually visible, and if the board has more than 2 layers you won’t be able to see the internal layers. Still, reviewing the external layers alone should provide some clues as to the quality of the design.
First, look to see if all the traces are running in straight line segments with no sharp bends. Sharp angles can be troublesome for some high power and high frequency traces.
Instead of trying to determine which traces can acceptably have 90° bends, it’s best to simply avoid them. In any case, most CAD PCB layout packages can be set up to avoid this problem.
Note that there are exceptions to this. Some printed inductors are square concentric spirals, and some printed antennas have sharp bends. Both of these, however, are easy to recognize.
All chips need power to function, but what happens when the power source is some distance away from the chip needing the power? In these cases, power has to be brought to the chip via a PCB trace (although typically via a PCB power plane on an inner layer).
Decoupling capacitors are placed very close to the chip’s power pins in order to filter out any high-frequency noise from impacting the chip negatively.
In general, if a chip has more than one VDD pin, then each such pin requires at least one decoupling capacitor, sometimes more.
These decoupling capacitors should be physically placed very close to the pins they are supposed to decouple. If this doesn’t happen, their effect is greatly reduced.
If your PCB design doesn’t have decoupling capacitors placed right next to the power pins on most of the microchips, then that is a big indicator that your design was not done properly.
If you have hired someone to design your PCB and they don’t deal with decoupling capacitors correctly, then you should find a new designer.
The length of the PCB traces must be matched in designs that require a precisely timed relationship between multiple signals. For example, this is critical when routing a high-speed clock signal to multiple chips or the data and address bus lines running between a microprocessor and RAM memory.
This ensures that all the signals arrive at their destinations with the same delays, thus preserving the relationship between the signal edges. This requires access to the schematics, and knowing which set of signal lines require precise timing relationships.
Then, follow the traces to see if some kind of trace length equalization has been implemented (called delay lines). These delay lines will often times look like squiggly lines as shown in figure 1 below.
Note that vias in the signal path cause additional delays. If these cannot be avoided, check that all sets of traces that require a precise timing relationship have the same number of vias. Or, you can use delay lines to compensate for the delays caused by the vias.
If your design includes a radio transmitter, receiver, or transceiver (transmitter and receiver combined), then it has to have an antenna.
To achieve the best performance, the feedline between the radio frequency (RF) pin on the RF chip should be impedance matched to the feedline connected to it. This feedline, in turn, must match the impedance of the antenna.
This impedance matching is necessary in order to maximize the power transfer between the antenna and the radio chip.
Any mismatches will cause a decrease in the actual transferred power, and hence a reduced operating range. This feedline is simply a PCB trace with controlled impedance that matches the antenna impedance, which is usually 50Ω.
If the transmitter output impedance does not match the impedance of the feedline then a matching network consisting of inductors and capacitors is usually employed.
In order to achieve a controlled impedance, the feedline is a PCB trace with a calculated width running over a ground plane. The width of this trace depends on the thickness of the copper trace, the thickness and dielectric constant of the PCB substrate.
There are many online tools used to calculate the exact width required for a given copper thickness and substrate material, and it is a good idea to confirm that this indeed is the case in the actual PCB. My favorite is a free software that you can download from Broadcom called AppCad.
If the antenna is a PCB antenna it should be on one edge of the PCB, free and clear of any ground plane. It should be clear of any other traces and away from any large components.
Silkscreen markings around the antenna are usually fine but copper markings, such as a PCB number or company name, can detune the antenna.
In addition to the placement of decoupling capacitors, there are some other considerations for placing components on the circuit board.
Here are some things to watch out for:
If the circuit contains inductors, they should not be placed too closely together. Inductors create magnetic fields. Placing them close together, and specifically end to end, can cause unwanted coupling between them.
Furthermore, inductors should not be placed close to large metallic objects. The magnetic fields can induce currents in these objects, and this can change the value of the inductors.
Toroidal, or donut-shaped, inductors are usually less prone to have stray magnetic fields, so their effects are less of a concern. If you cannot avoid placing inductors close together, then they should be placed perpendicular to each other to reduce unwanted mutual coupling.
If the board contains power resistors, or any component with significant heat generation, you need to consider the effect of the heat on other nearby components.
For example, if the circuit contains thermistors to compensate for ambient temperature effects, then these should not be placed close to any power resistors. The same applies to temperature compensation capacitors.
If the circuit contains an on-board switching regulator, then all components associated with it should be physically localized to a section of the PCB, and as far away as possible from sections handling small signals. These tend to generate significant switching noise that can negatively affect sensitive circuit sections.
If the PCB has AC mains applied directly to it, usually in the power supply section, then the AC side should be localized to one section of the board.
In addition, the PCB itself should have a physical barrier separating the AC from the rest of the board. Typically, this is accomplished by having a slot in the PCB separating the two sections.
Traces carrying high currents should be sized appropriately. The IPC (Institute for Printed Circuits) recommended trace (also sometimes called a track) width for different current ratings are shown in figure 2 below:
Traces carrying small analog signals should not run parallel to traces carrying digital or fast changing signals, due to noise pickup issues.
Also, in general, traces connecting inductors should not be any wider than necessary. These can act like antennas, and produce unwanted radio frequency emissions.
For any moderately complex PCB it is best to use at least a four layer board with the two inner layers being the supply and ground plane.
If the design contains both analog and digital sections, the ground plane should be split, and only joined at a common point, usually the power supply negative. This avoids large ground current spikes from the digital section adversely affecting the analog section.
If using only two layers, then each sub-circuit ground return trace should be separate, and all of them should then join at the power negative terminal.
It is bad design to have the ground return of any sub-section, or IC, join into a common ground return path back to the power supply negative as illustrated in figure 3 below.
The issue here is that PCB copper traces do have some resistance. Thus, current through the trace will cause voltage drops. In the example above, the chip at the far right end of the trace will see its ground reference at a higher voltage than the true ground reference.
What’s more, its ground will bounce around depending on the return currents of all the chips to the left of it in the illustration.
Whether you are learning to design your own PCB, or you plan to outsource it to an electrical engineer, you need to be able to judge the quality of your PCB design.
If you have no design experience and you outsource the PCB design then pay attention to the seven areas highlighted in this article to determine if your engineer is worth what you are paying them.
In fact, if they fail to meet any of these seven criteria then I’d suggest you consider finding a new designer. On the other hand, if you are designing your own PCB, then be sure you avoid these common mistakes.
Regardless though, it’s always a good idea to get a full design review by an independent engineer before proceeding to board prototyping.
Are you frustrated and overwhelmed trying to develop and bring your own product to market? If so, now you can finally get the help you need to succeed!
If you need engineering support, coaching, training, and connections to help bring your new electronic hardware product to market then be sure to check out the Hardware Academy.