Today was kind of strange. I normally am pretty busy doing designs. It's busy enough that I try to ignore as many distractions as possible, try not to leave the house, and mainly just concentrate on what I'm designing, milling, assembling, or whatever else needs to be done. But a Kickstarter project was brought to my attention via Twitter that for some reason, struck enough of an emotional chord in me, that I felt the need to comment on it .

I'm not a stranger to posting comments. Most people that know me also know that I'm opinionated and can sometimes be a bit of a jerk about it. This was a bit different though because not only did it require me to spend the time and thought to write the comment, but I also had to pay $10 to do it. The issue at hand was a Kickstarter project that, in it's campaign sales pitch, overtly stated that it was a direct clone of the Makerbot Replicator . It was actually used as a selling point.
It's been a long time since I blogged on my site. I was burned out from the radiation monitoring buildout and having multiple things going on at the same time. The time away was good so that I could focus on projects I've been wanting to do for a long time. Since then, I've started on a lot of interesting projects and I've actually wanted to talk more about them. Posting bits and pieces on social media outlets is not the same. I've also had a lot of time to think about many different things. I guess this means that I'm going to restart blogging again. This post is mostly just to get things going so I don't have that huge mental barrier to overcome. More later :) 
I recently got into an interesting discussion on Twitter with some other engineers regarding the parallels between dancing and engineering. I often get a surprised look from people when I tell them I used to be a professional dancer. Perhaps its because I look like a nerd, or perhaps its because I am one. In any case, its true and its something that I spent many years and countless hours doing. 

The strange thing is really that it's nothing different from engineering. Engineering is also something that I've spent many years and countless hours doing. In both cases, they started out mostly just for fun, and once you get good, you can make money off it. But that's not what I really want to talk about either. 

This is just a node testbed



The Safecast bGeigie is an Arduino-based radiation data logger that is being used to generate data for the safecast radiation map . It uses the Freakduino-Chibi board and a customized data logger that interfaces to an International Medcom geiger counter to geotag all the radiation data. Within Safecast, we're currently trying to have one bGeigie travel to hackerspaces around the world and measure the radiation in those areas.


Link to Make Magazine

Ugh. Analog Devices put up a great video tutorial on Thermocouples, but had incoherent links to the 8-part series. They were meant to be watched in series but Youtube doesn't organize the videos properly. Here arelinks to each part in the series in the correct order they should be watched in.

Part 1: Thermocouple 101: What is a Thermocouple?

Part 2: Thermocouple 101: Cold Junction Compensation

Part 3: Thermocouple 101: Measuring the Tiny Signal

Part 4: Thermocouple 101: Setting the Common Mode Voltage

Part 5: Thermocouple 101: Open Thermocouple Detection

Part 6: Thermocouple 101: Filtering a Thermocouple

Part 7: Thermocouple 101: Thermocouple Nonlinearity

Part 8: Thermocouple 101: Compensating for Nonlinearity

I recently got a very nice surprise in the mail.  @wa7iut, aka Bob, from Ambient Sensors sent me one of his latest breakout boards. I've been itching to try out the LTC3108 for a while because it can boost input voltages as low as 20 mV up to a very usable 3.3V. People have been sticking probes into plants to power their sensor nodes using these chips.


Bob is well known in the open hardware scene and also has been doing a lot of interesting work in the sensor network field. My personal favorites are measuring the impact of tackles in high school football and setting up irrigation monitoring at a wine vineyard.


I'm sure a lot of you reading this are familiar with the situation in Japan right now. A horrible earthquake and tsunami occurred and along with all the destruction, it also caused a meltdown at a nuclear reactor near Tokyo. Since then, Tokyo has been suffering from nuclear fallout and tainted food and water. As of this post, we've just been informed that the tap water in Tokyo is tainted with radiation, there seems to have been a run on bottled water, and the situation is getting very disturbing (as if a nuclear meltdown in your backyard is not disturbing enough).

The day after the nuclear problems started occurring at the plant, geiger counters started popping up on Ustream. After that, Pachube set up special accounts for radiation data feeds in Japan (thank you Pachube). Unfortunately, geiger counters were sold out everywhere. The fear of nuclear disaster and radiation spread internationally and there was a run on geiger counters. Luckily, Tokyo Hackerspace was able to obtain two of them from Reuseum . They had actually bent over backwards getting them to us quickly and was calling their warehouse for stock and UPS and FedEx to see who would still deliver to Japan. We received them two days ago and I brought them to Tokyo Hackerspace yesterday to show people how to use it. We're keeping one at the space so that people can borrow it to check out their living area and reassure their families that its safe. Here's a pic of me scanning Karamoon , another Tokyo Hackerspace member. His head was looking very suspicious...

I wanted to put the other geiger counter up publicly and as quickly as possible to share the data with others in Tokyo. Unfortunately, the geiger counters are completely analog and there was no way to pull data from it. So, being the nerd that I am, I proceeded to hack it into what I wanted. These are the project details of the process of converting a cold-war era, analog geiger counter into a device that can digitally send data to Pachube, a public sensor feed aggregator. 

Also, I wanted to mention that I decided that this geiger counter would reside outside on my balcony, although inside a cardboard box. The reason for this is that most of the geiger feeds in Tokyo right now are indoors and I noticed a larger variance in geiger measurements outdoors versus indoors. I checked the measurements of this geiger inside my apartment and they follow closely with the official government numbers as well as other geiger counters around Tokyo. I figured its better to have it outdoors so that people can get an idea of what they're being exposed to when walking around. Most of the fallout is particulate matter. As a point of reference, the normal background radiation in Shinjuku is 0.035 uSv/Hr .

You can download the Arduino and Processing code that collects the data and sends it up to Pachube after the jump. The pics are also there.

Things are calming down somewhat here in Tokyo and the local foodbank said they have enough volunteers for the time being. So I figured I would get to work on helping out with the collaborative geiger counter project being hosted at SEEED studio . Tokyo Hackerspace has 10 SBM-20 geiger tubes on their way and we need to get to work designing the circuit schematic and PCBs for the geiger counters. We have a status update on all the projects that are going on currently due to the past events and you can see it here:


Anyways, the first order of business is generating the 500V DC needed to run the geiger tubes. This is one of the main challenges since it's not easy generating those types of DC voltages. Luckily, the geiger tube does not consume a lot of current. The 500V is just used to set up an electric field strong enough to generate an avalanche process. The quick background is that a photon ionizes a molecule into positive and negative charged components. Under normal circumstances, they would just recombine immediately. However in a strong electric field, the charged components separate and move towards their respective sides of the electric field. If the electric field is strong enough, ie: the voltage is high enough, then the charged particles ionize other particles in the gas inside the tube. This becomes an avalanche effect and when all the charged particles hit the walls of the electric field, a voltage pulse can be detected. This becomes an "event" and a geiger counter counts the number of events per minute. 

The Tokyo Hackerspace site is offline at the moment due to a tremendous surge in traffic. The members with IT expertise are working on it now. In the meantime, if you want to send material donations, you can send them to us at the hackerspace and we can box them up into care packages and have runners distribute them to the local drop points for relief efforts. Here is a list of what's needed, compiled from various organizations and also hackerspace members. We deliberately trimmed items that are heavy due to international shipping costs.

The address to ship material donations to is:

Tokyo Hackerspace
Tokyo-to Minato-ku
Shirokanedai 5-11-11

  • Ear plugs
  • earphones
  • eye masks
  • baby bottles
  • powdered baby formula
  • energy bars
  • portable water tanks (collapsible)
  • portable water filters
  • paper cups
  • lanterns
  • first aid kit
  • dust masks
  • soaps
  • towels
  • blankets
  • gloves
  • flash lights
  • slippers
  • candles
  • lighters
  • pocket knives
  • trash bags
  • aspirin/ibuprofen
  • pain killers
  • sanitizing gel
  • paper plates/cups/spoons/forks/chopsticks
  • Nappies
  • Moist wipes
  • Warm Jackets - Baby/kids/adult
  • Toys
  • Dry goods
  • Kids activity books
  • Kids coloring books

Thanks for the huge amount of support and encouragement that we're getting internationally.



Hi all.

I just wanted to write a post thanking everyone for all the support. I received a lot of great feedback and Tokyo Hackerspace received enough donations to buy another 100 solar cells for the solar lanterns. The solar cells and the PCBs are the most important because they can't be sourced locally. That brings us up to 150 lanterns that will get produced once all the parts arrive. I'm going to turn the hackerspace into a sweat shop. Definitely a good way for people to learn how to solder.

I'll be trying to get back to some semblance of normal life tomorrow. The news feeds should hopefully resume tomorrow as well.

Things were so crazy the past few days that it took a lot of mental and emotional stamina just to stay sane. I was luckily able to overcome the initial shock of the earthquake, tsunami, and then hearing that multiple reactors were melting down just around the corner. There was also the race to get emergency supplies since all bottled water and dry goods were selling out quickly on Saturday. One thing they don't tell you is that the reason you need to stock up on emergency supplies is because mass hysteria will create a shortage very quickly. On top of that, people were freaking out right and left (mostly outside of Japan) and needed to be calmed down. 

In the hackerspace, we got together last night and decided on the upcoming projects to deal with the events that have unfolded. We'll be assembling the lanterns which will probably be needed for some time. The northern region of Japan will probably not get properly wired up for electricity for quite some time so many people that stay in the region will be spending their nights in the dark. We're also going to start testing out long distance Wi-Fi connections to see if we can spread and distribute basic internet access for people to communicate. Hopefully we can get Asterisk and SIP phones going so that people can communicate easily, even if they don't have phone service. I've already stockpiled six wireless routers and made sure that they can be flashed with DD-WRT. 

To deal with the nuclear situation, we ordered two Geiger counters that were thankfully supplied by Reuseum. There is worldwide hysteria at the moment on radiation clouds and just about all commercial geiger counter outlets are sold out. He stepped in and sold us two nuclear facility grade geiger counters out of his stock and is having them FedEx'd to Japan. That will help us calm people down, both in the hackerspace, and Tokyo in general. We'll be UStreaming the geiger counters so that people can see the live readings in the short term.