Growing up in the 90s, I love early rap. One of the best songs played at my 8th grade dance was "Slam by Onyx." That's why I was excited to interview our community member and IoT Hero, Tim Gipson (or as you know him Drmn4ea) on the Slam Stick X, along with other cool thinks like flying helicopters blind.
So, tell me a little bit about yourself.
I'm Tim Gipson, director of electrical engineering at Mide Technology Corp. I've been here about ten years now. We're a small company and an even smaller EE department, so my experience has included the full range of analog and digital design, mechatronics, prototyping, technical writing, and, of course, lots of programming, ranging from low-level (firmware in assembly and C) to high (mostly Python). In my spare time, I contribute to hardware jailbreaking efforts and dabble in open-source electronics projects such as Mosquino, an energy-harvesting Arduino derivative, and a networked RGB LED lighting system.
Tell me a bit about your Mide.
Mide specializes in "smart materials" applications, using materials, such as shape memory alloys, hydrogels and piezoelectrics, to solve specific problems. For example, we've used SMAs in self-deploying structures, high-efficiency UAV propulsion and safer pyrotechnic devices that won't explode in a fire. We use reversible hydrogels in a bulkhead shaft seal for Navy ships; this is installed where the propulsion shaft passes through a bulkhead wall, activating on contact with water to seal and isolate ship compartments in the event of a hull breach. We use piezomaterials for vibration energy harvesting, actuation and damping, high-speed valves, micro-positioning and high-fidelity haptic devices. The skin is a wide channel of mostly-untapped sensory bandwidth; we're currently building intuitive haptic vests and control interfaces for soldiers and pilots - you can actually fly a helicopter blindfolded with this, using only tactile signaling. I sat in with someone doing exactly that in one of the country's most advanced rotorcraft simulators; it was very impressive to see (and feel)!
More recently, Mide and its partners have been working on distributed condition-based maintenance applications, in which wireless sensor nodes distributed throughout a mechanical system work together to identify degrading components in the system and estimate their remaining life. With this, maintenance can be performed only where needed, rather than blindly replacing parts based on a calendar or usage-hours schedule, and maintenance downtimes can be planned more efficiently, saving billions industrywide. We're especially focusing on applications where ultralow-power electronics and environmental energy harvesting enable truly maintenance-free, "stick on anywhere" solutions.
I know you guys make the awesome Slam Stick X. Can you talk about what it is, why it's cool, and how people are using it today?
The Slam Stick X is a high-fidelity portable vibration data logger in a USB thumb drive. There are many other accelerometer data logging options, but some things that set Slam Stick X apart are high sampling rates, high g-level ranges (up to 2000g), user-configurable hardware antialiasing, event triggers (such as altitude), and the certification considerations that make it suitable for demanding applications. This includes military-grade EMI/EMC qualification (MIL-STD-461F), FOD (foreign object damage) design considerations for use in aircraft avionics bays, and fully NIST-traceable calibration over a wide temperature range. You can pull it out of your pocket and stick it on a structure using double-sided tape, and get results on par with a rackful of expensive equipment requiring hours of setup time per test.
Slam Stick X was initially designed for the US Navy to perform in-flight qualification testing on F-18s; they needed a standalone shock & vibration measurement tool that could be easily stuck onto just about any part of an aircraft, inside or out, and safely flown - without wiring or aircraft modifications. Previously, such testing was done with a set of specially-instrumented aircraft, with racks of custom equipment and wiring everywhere. The safety clearances for such wired instrumentation are surprisingly expensive and take ages; since there were only a couple modified aircraft to support this, there was also a very long waiting list to get access to one for a test. Now, the setup time is in minutes and with whatever aircraft is handy.
Many customers don't say what exactly they're using it for, but we know they include a well-known smartphone company, a well-known search engine company, and manufacturers of products ranging from helicopters to professional movie cameras to bulldozers to breakfast cereals. Product development and qualification seems to be the most common use for Slam Stick X.
We've also heard from customers using them for human-factors analysis on vehicles and power tools (allowable vibration transmitted to the user), to optimize and size vibration energy harvesters, instrument fragile shipments, measure small variations in equipment performance, and instrument race cars. One customer inquired about using Slam Stick data to guide policy in a historic building district by comparing the impact of nearby heavy vehicle traffic on the building foundations to earthquake-equivalent magnitudes, following the collapse of one of the buildings. Another is using them to identify and reduce damage sources to fleet vehicles - in one case they were able to correlate an unusually high occurrence of a specific damage pattern (broken rear springs and axles) to a specific set of speed bumps in a housing estate, which drivers were cutting through on their way back to depot. They've even been used to measure rocket launch forces.
I understand that it uses the Silicon Labs EFM32. Why did you choose that MCU?
A combination of factors, but our main reason for selecting the EFM32 family was their low-energy features. A well-designed EFM32 application allows a lot to happen autonomously while the CPU core sleeps, which both lets us record longer on a single battery charge and perform more processing with a modest CPU speed. In particular, the combination of ADC scan mode, hardware-accelerated oversampling, Peripheral Reflex System and DMA is a killer combination that lets us scale down power usage with sample rate while still providing good noise reduction across the board.
Some other features that drew us to EFM32 were the strong support for open-source development tools, and the API consistency of the vendor-supplied libraries between devices in the Gecko family. The current device targets high-speed measurements on the order of hours to days, but we plan to offer additional products based on its design, targeting operating ranges more in the months-years range. Being able to squeeze down power consumption even further and move freely between larger and smaller devices will allow us to offer this kind of variety more easily.
Cool! Well, it’s a big question, but in your opinion, what does the future of IoT look like?
"IoT" has been around the hype cycle a few times. A decade ago, the rallying cry was "control your home thermostat remotely" and "put your toaster on the internet" and the natural response was "Why would I want to do that?" I think we're at a point now where both the technology infrastructure and application mindset are finally catching up to that hype enough that it could take off this time.
On the technology side, modern low-power sensors, CPUs and wireless technology will enable the deploy-anywhere-and-walk-away sensing applications that will make IoT devices approachable to nonengineers just trying to solve a problem. The ongoing adoption of IPv6, cheap cellular and other emerging data services will remove cost and infrastructure barriers, which until recently have led us to "small local networks of things dangling off cable modems," and requiring proprietary 3rd-party cloud services to mediate contact with one another across NATs and firewalls. Finally, implementors are now envisioning and promoting more realistic applications, ones that solve real problems and promise real returns on the investment.
So I guess I see the IoT growing, but with more of a sustained simmer than an explosion for now. It won't be in every home soon, and our toasters won't be on the internet, but there will still be millions of nodes deployed in targeted niche applications like smart metering, condition-based maintenance and health monitoring, distributed environmental sensing, smart asset tracking and the like. Many fleet vehicles already report back their GPS location and various status variables, but this will filter increasingly down to things like dumpsters, shipping crates, bicycles, port-a-johns and pet collars. Mostly commercial and industrial users at first, with the bulk of the end-consumer-facing applications coming later.
Most of the industry won't be buying "IoT" for its own sake though; they're interested in solutions, however they work under the hood. I expect to see many more networked CBM sensors in the near future; this is one niche where inexpensive collections of networked sensors can provide large and immediate paybacks. And yes, networked Slam Sticks are definitely in the plans - but no one company can release every sensor or solve every problem. Multi-vendor interoperability following open standards is what will really enable the applications that sell IoT solutions to industry.
If you have a question for Tim, comment below.