I was just watching the PBS FrontLine documentary on the Digital Nation and it completely irritated me. Here were professors from MIT, one of the best technical institutions in the US, complaining about the students’ use of technology. I can’t even say that this is ironic, as much as it is just plain stupid.

The crux of the argument is that students these days are completely distracted because of the internet. They’re in the classroom, but rather than listening to the lecture, they’re googling things, reading articles, or probably chatting with their significant other. The professor is frustrated because he gave a simple exam that just tested on whether the students were paying attention in class and the students score poorly. The immediate thought that came into my head was why was the professor blaming the students rather than his teaching methods.

I teach classes at the Tokyo Hackerspace. My first class was a basic electronics class that was done with a lecture format and I took three hours to deliver everything I thought participants needed to know about electronics. It was enough information to give them a firm foundation and understand the basics of voltage, current, resistance, capacitance, and simple design patterns. That was a mistake, and the problem wasn’t the participants, it was with my assumption that they wanted to know the basics of electronics.

I finally realized that the problem was that I was telling them the basics so they could build on top of it. But without experiencing it for themselves, they would never understand why you need to limit the current of an LED or why you need to have bulk capacitors on a power supply. One of the reasons why the new MAKE: Electronics book is so great is because they encourage readers to break things as well as make them.

Anyways, I finally grasped the concept that people want to discover things for themselves. They want to understand why certain things are the way they are, rather than just be told it. They want to build things and customize them to make it their own and put their stamp on it. This is the proper way to teach people and has been for centuries, where the old master/apprentice relationships still existed.

This post is a slight departure from my normal posts which are usually about wireless. But since I'm technically part of the wireless sensor networking world, I figured a fun, little post about sensing might be appropriate.

I actually put this together about six months ago to show to the Tokyo Hackerspace back when we didn't have a space. We were meeting in restaurants and would show off our latest weird designs over there. It was really a horrible place with a lot of loud drunks and people shouting at each other. And that was just inside our booth :)

Anyways, I showed them that if you used capacitive touch sensors, you would actually be able to draw your own buttons and be able to sense touch events on them. Incidentally, if you tweak the sensitivity high enough, you can also sense touch events through insulators like wood and plastic which I always thought was kind of cool. Perhaps I'm going to play with that some other time.

I decided to blow off some steam today because it's been so busy trying to get the webshop up and decided to hang out in Akihabara. After I arrived, I realized I didn't have anything I really needed to do, but just so happened to have my digital camera with me. I often get asked to show people around Akihabara and why I like the place so much. Since I had some time on my hands, I decided to do a graphical tour of Akihabara so people might be able to see a small piece of it through my eyes. These are the really hardcore shops, most of which you won't see from the tourist pics most people post. Hope you enjoy them :)

I didn’t get a chance (or actually I forgot) to wish everyone a Happy Thanksgiving. I’ll be doing my end of year reflection soon and I already know that I have a lot of things to be thankful for.

This Thanksgiving holiday wasn’t much of a holiday for me though. Since I spent so much time helping Tokyo Hackerspace prepare for the MAKE event, the holiday was spent trying to catch up with my designs and get things ready to roll out for the store. I’ve already decided to put off opening the store for this year since the holidays are quickly approaching and the last thing you’ll want to be doing over the holidays is prototyping wireless sensor circuits and writing code. However I do need to get over my mental blocks and insecurities and just get the damn thing open. You know things are bad when your wife starts pressuring you to open the store.

I already have the first wave of products ready to release. It’s going to consist of the 128 kB AVR board, the AT86RF230 radio board, and the prototyping breadboard. I’ll also have some other items like hi-gain directional antennas and such. It’s a pretty sparse initial offering, but there’s a reason for it.

I was initially going to release the Chibi board as well, but the time at MAKE and working with the scrolling LED board I designed taught me a couple of lessons. One of the things that I wasn’t too happy with is that Chibi is running a naked battery. By naked, I mean that it can run off a battery, but it’s running directly off of the battery with no power supply conditioning. The initial version of the scrolling LED boards I designed for Tokyo Hackerspace were doing the same thing, but I didn’t like the fact that the batteries dropped in voltage. Those nice flat discharge curves you see from the manufacturers aren’t exactly true. Those curves are flat so it looks like batteries retain their voltage until they’re almost fully discharged. Unfortunately, as those of you with cars might understand, when batteries are under load, the voltage does indeed drop as it discharges and it can be up to 1V or more. That’s why I wasn’t so happy to see the LED displays dimming out when the battery manufacturer had such a nice flat discharge curve for their lithium coin cells.

If you've been wondering why I haven't blogged as much recently, it was mostly because I was working with Tokyo Hackerspace to prepare for Make Japan #4. It was the first Make event for the hackerspace since it started and there was a lot to do. Since we've only been in the project space for three months, there wasn't a lot of stuff to show, so we all had to hustle to put together things to display there. I made a portable, hackable, scrolling LED sign which could be battery operated or USB powered. There was also a Windows app to change the messages. It was especially difficult because it was made to be sold rather than just for display. Hence, I had to make everything easy to use, write up documentation, design the boards, and work with the other hackerspace members to assemble them. For something that seems so common, a lot of work went into them. The project was open source for software and hardware and all the project files, schematics, and source code can be found here .

Other members were also working on interesting projects like turning common components like resistors, capacitors, etc into wearable jewelry, and doing mechatronic animation of squid characters. We were also working with the MAKE Japan team to run a public soldering area where people could build whatever they bought at the event at our booth. Unfortunately we didn't know that we'd also be teaching how to build the kits and since we were dealing with all types of kits, we had to learn how to sight read instructions and teach soldering techniques at the same time. Overall, it was really fun, and we taught a lot of people about electronics and soldering. I liked seeing the face of conquest that people had when it was their first time soldering and they put something electronic together that actually works.

I’m taking a break from my seemingly neverending hardware assembly process because I was suddenly inspired to write a blog post about the future of WSNs as I see it. I’m not an analyst, nor would I want anyone basing their decisions off of something I said. However I do have the luxury of meeting with quite a few people in the wireless sensor network community (both Zigbee and non), hanging out with a rather large crowd of uber geeks (Tokyo Hackerspace), and am exposed to WSN news just about every day of my waking life for the past two years from updating the blog’s news feed. So in a way, that makes me slightly more qualified than some dumbass research groups (like ABI Research) that pay their interns to surf the web and collect datasheets, parts specs, and articles to put together a multi-thousand dollar research report based on publicly available data.

The past two years that I’ve been heavily involved with wireless sensor networks have been very interesting and, I daresay, exciting. I’ve actually been involved with WSNs on a very superficial basis for longer, but the last two years got me kind of deep into the middle of the pile. When I first started collecting news, it was to try and aggregate the disparate and sparse information that would occasionally surface. Today, I find myself spending a lot of time every day sifting through all the wireless sensor press releases, blog posts, and related information that seems to be flooding the internet. The verdict: wireless sensor networks’ popularity is increasing at a frighteningly fast pace.

People following this blog are probably wondering what I’ve been doing the past four months. Well, I’ve discovered that developing wireless sensor network hardware has been more of a challenge than I had anticipated. The design was actually the easy part. It’s everything that comes after that makes my life difficult. When I started on the hardware development, I thought that I just needed to design the boards, tune the radios, and stick them in a web storefront. Looking back, I’d say this was completely naive. The original idea was to have a supply of boards both for my own use and to sell in a webshop. My eventual goal is to make this open source project self-sustainable and I had figured that making hardware was the easiest way to get there. That was a gross underestimation.

One of the things that I discovered is that designing a schematic and making a PCB is just one small part of the overall design process when you’re trying to bring a board to market. There are a lot of factors that get ignored or underestimated like prototyping, sourcing components, prepping for manufacture, testing, writing documentation, and of course, the killer issue of all low-volume hardware outfits: assembly. A lot of these areas are trial-and-error and the error part is what consumes a lot of the time.

In the last four months, I’ve designed seven PCBs: three for Tokyo Hackerspace, four for FreakLabs. In that time, I’ve learned quite a bit about the flaws in my overall design process   and also the business side of trying to manufacture and sell boards. I’ve made a lot of mistakes that could have been corrected in the design phase if I had more insight into how I was going to manufacture and assemble the boards, but it’s tough to get that insight without going through the overall process a few times. I can’t really complain because although the past four months have wreaked havoc on both the Zigbee project and my personal life (and made me even more anti-social than I used to be), I have to say that I’ve probably also accumulated more hardware, manufacturing, and business knowledge than I’ve ever had in my entire career.

Everyone talks about the machine-to-machine (M2M) universe where the information from a plethora of cost-effective sensors allows people and systems to make even better decisions. One of the many challenges has always been the connectivity required for these sensors.

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