The month of July had a number of new and notable projects certified as open source hardware that are worth checking out. This month saw fewer projects certified than in previous months; and it appears that the initial rush by the likes of AdaFruit, Sparkfun, and Olimex to certify their product lines has tapered off. This is a good thing as many of the dev boards you have at home are probably now certified as open source hardware. I have also heard reports that organizations have taken notice of the certification website and are using it for data mining purposes, such as understanding the popularity of different components and common design patterns. This is one of the wonderful side effects of certification; it creates a corpus of data that curious data scientists can use to objectively characterize the various design processes. Now it is possible to not just evaluate different designs, but look at the prevalence of certain designs over others.
Kicking off this month’s featured projects is a topic near and dear to my heart, and well, everyone’s heart really: blood pressure monitoring. Blood pressure is a critical health metric that is also extremely annoying to collect; we’ve all sat nervously in the doctor’s office while they painfully squeeze our arm with that annoying cuff. Since this metric is annoying to collect it means that people aren’t as diligent at monitoring it as they could be, which leads to poor health outcomes. Our first featured project attempts to collect pulse, dissolved blood oxygen, and blood pressure using only a simple circuit board. The project is called, “Continuous Non-Invasive Blood Pressure Research Platform – ECG and PPG Pulse Arrival Time Based” and it is a research project from Taiwan. The platform attempts to use the difference between two metrics, PAT, or pulse arrival time, and Pulse Transit Time to calculate a correlate for blood pressure. The system is still in the research phase, but it looks promising. The hardware appears to collect reasonable data but there is probably still a lot of work to do to verify the results are valid for medical applications.
Our next freshly certified project comes from a far off place that few could find on a map. What I love about the open source hardware community is how open designs can travel around the world and be used, studied, and re-mixed, by other wonderful nerds. To that end, July saw the first project certified from the tiny African island nation of Mauritius. The StormDuino is an arduino clone made by two groups of Mauritanians, CyberStorm.mu, and Tecknologg. What stood out to me about this project was that it has a USB-C connection (which is uncommon for arduino clone boards) and that it was created entirely in KiCad. The board also has a really slick Dodo bird silkscreen to distinguish itself as a product of Mauritania (the birds used to live on the island).
When we talk about open hardware most people think about electronic things like circuit boards and perhaps the stray CAD model for a 3D printer project, but really open hardware can be just about any physical object. For that reason I was really excited to see what to my knowledge is the first certified piece of furniture, a simple planting bench. I am an avid gardener and a planting bench can be a real back saver when you are mixing up that perfect batch of orchid mix. What I like about this project is that it is a starting point for a discussion about how we should document, record, and share woodworking projects. The author does a great job of diagraming out the design and the materials. What seems to be missing are the instructions on how the whole thing goes together (i.e. where the screws go? What are the sub-assemblies?). If you’ve ever put together flatpack furniture from a well known Swedish retailer you know that the order of operations and clear instruction can be very important. We would love some feedback from the woodworking community on documentation best practices. If you have thoughts on how best to document these kinds of projects please feel free to drop us a line.
Our last project touches on a subject that many makers find both very interesting and very difficult to approach: FPGAs. The BASIC-ECP5-PCB is a development board / reference design for the Lattice ECP5 FPGA. The ECP5 is a low cost FPGA intended to act as a co-processor / accelerator to a larger microprocessor or a replacement for an ASIC. This FPGA is very hacker friendly as it has an open tool chain and sports a 0.8mm pitch ball grid array making it easy, or at least feasible, to use in home assembly projects. This particular development board mates with a RaspberyPi so it can be programmed and tested remotely for easier application development. The BASIC-ECP5-PCB lays out all of the circuitry you’ll need to program and run the FPGA including on-board flash memory, and a switch mode power supply. This board is a stepping stone design for your own FPGA applications. I reached out to the developer Matt Venn about this project and his intended applications to which he replied,
I intend to use it for DSP experiments. Lots of PMODs for extra memory, ADC, DAC etc, and lots of space on the FPGA with hardware multipliers. The attached Pi is used for wireless programming, and can also communicate via SPI, I2C, serial, GPIO.
That’s it for this month’s freshly certified open hardware projects. If you have a project that you would like to certify, all of the details can be found on the certification website. The certification website also lets you search through all of the certified projects and directs you to their documentation and design files. If you are not quite ready to certify your project, and would like someone to review your work, feel free to reach out to the Open Source Hardware Association on twitter and we’ll see if we can find someone to help review your design.