Summer has been in full swing for some time now and this means sunshine, outdoor play, and no homework have filled kids’ days for the last couple of months! But just because the kids haven’t had to go to school for a few months doesn’t mean that learning can’t jumpstart before the school year begins again. In fact, this just might be the perfect season for mixing the outdoors with STEAM (short for Science, Technology, Engineering, Art, and Mathematics) education and do-it-yourself (DIY) maker projects. STEAM learning combined with DIY maker projects is a great way to do some hands-on, project-based learning that will be a great mental warmup for your kids’ just before heading back to school in the fall.
This STEAM-inspired three-article series will explore the available resources to assist you and your kids on a maker’s adventure and walk you through an embedded electronics project. We will cover the design, build, and code for the project as well as discuss how the data from the project can be useful to develop analytical and critical thinking skills. In this first segment, we will direct you to the resources that are available to get you started.
Someone once said “hardware is hard.” However, the reality is that hardware has never been more accessible, regardless of your technical background. Most major manufacturers of microcontrollers offer some sort of development board. These boards allow engineers to prototype concepts rapidly and test a hardware interface with a specific embedded platform. For the purpose of this series, development boards will serve as a shortcut. Instead of worrying about breadboarding a system from scratch (which is admittedly fun and should be tried at least once in your electronics education), starting with a development board ensures that we spend more time on the science involved in developing the bigger picture and less time troubleshooting the power or timing circuitry.
Perhaps the most popular maker-oriented microcontroller platform is Arduino. It is (of course) not the only platform that is available. In fact, if you or your kid already has some experience with Arduino boards, it might be worth using this time to expand your horizons and try a different platform. Check out Mouser’s Open Source Hardware site (Figure 1) for a list of great options, including product lines such as the STMicroelectronics Nucleo, TI LaunchPad, and BeagleBoard.
Figure 1: Mouser’s Open Source Hardware site lists great hardware for summer and year-round electronics projects. (Source: Mouser.com)
I recommend using a development board where the general-purpose input/output (GPIO) pins are at least 5V tolerant. While 3.3V are becoming increasingly popular (though even lower voltages for special applications with a significant need for energy efficiency are now required) for microcontroller platforms, many older, less expensive sensors and actuators popular among makers require 5V.
Speaking of sensors, for prototyping it is good to see if a desired sensor is offered as a so-called “breakout board” (BOB). Just like development boards give you functionality out of the box, a BOB lets you spend more time tinkering at the project level and less time troubleshooting to enable the sensor to work. Though you will pay a little extra money, you will ultimately save on time. Just be sure the microcontroller input/output (I/O) voltage and the BOB I/O voltage are the same; otherwise, an interfacing chip known as a level-shifter will be necessary.
The embedded platform you choose will dictate which development software and operating system you will need to use. Thankfully, Windows is pretty much the common denominator for most platforms, and chances are your computer is running either Windows 7 or Windows 10. Linux and Mac OS support is more abundant than a decade ago, but be aware that these two operating systems do not support all embedded platform development tools.
Here are two helpful hints to try if you plug a development board into your computer and nothing seems to happen: First, Windows machines, especially Windows 8 and prior versions of the operating system, will require Universal Serial Bus (USB) drivers. Check the documentation that comes with your board to get the link to download any necessary software. Second, not all USB cables are the same. Be sure to verify the mini-USB versus micro-USB connectors. Also, some USB cables are for charging only with no data transmission. If in doubt, swap the cable out for a different one to ensure you are using one that has data wires.
Crack open a notebook or fire up your favorite note-taking app, and start by sketching out the idea for your project and taking notes on potential parts. Personally, I like to download the datasheets into my note-taking app as well. One drawback to be aware of when using development and breakout boards is that sometimes they are hardwired in ways that make them incompatible with a specific type of integration. For example, once I was working on a project that involved two sensors that shared the same GPIO pins. It required me to cut the trace on one of the BOBs and solder a wire to a different pin. Checking out datasheets before buying any parts can help you detect these kinds of concerns.
KiCAD and EagleCAD are probably the two most popular platforms for circuit captures and printed circuit board (PCB) layouts. KiCAD is open source while EagleCAD, now a product of Autodesk, interfaces with tools like Fusion 360 for creating 3D-printable enclosures and mechanical components for your project. We will discuss this topic more in part 2 of this series.
I like to use Mouser's Saved Projects feature on their website to build my bill of materials (BOM). Not only does it help me check on parts availability and costs, but I can also easily share a prebuilt shopping cart with fellow engineers and makers who might have an interest in building a similar project. I also like that I get notifications when a part reaches its end of life (EOL), so I can keep my designs up to date. If you already have your BOM in a spreadsheet, you can also check out Mouser’s BOM import tool, which is another useful suite of tools in Mouser’s mobile website and iOS/Android apps. It is great for doing part research while on the go or if you’re out in the field and need the datasheet for a part that you’re troubleshooting. Check out the following resources for additional help with your parts:
Mouser’s Part Search Add-in feature is already installed in Outlook and Excel, allowing you to launch this feature with a single click and without opening any other program (Figure 2). The add-in feature also gives you the latest information, empowering you to make sound purchasing decisions. Each add-in displays the part number, the manufacturer’s name, the part’s description, and the latest pricing and availability at Mouser.com.
Figure 2: Mouser’s Microsoft Office Part-Search Add-in feature is launchable with a single click and without opening any other program. (Source: Mouser.com)
Look for project ideas throughout the school year and inspiration by browsing projects on Mouser’s Open Source Hardware site or others across the Internet. Many of these sites have projects as well as communities of makers and engineers who share news, reviews, and hardware tutorials.
That’s it for now, but remember to check back for when we jump into a step-by-step look at mixing together end of summer fun with hands-on making and STEAM learning in part 2 and part 3. Do you have comments or questions? If so, please be sure to let us know down below!
Michael Parks, P.E. is the co-founder of Green Shoe Garage, a custom electronics design studio and embedded security research firm located in Western Maryland. He produces the Gears of Resistance Podcast to help raise public awareness of technical and scientific matters. Michael is also a licensed Professional Engineer in the state of Maryland and holds a Master’s degree in systems engineering from Johns Hopkins University.