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Safecast bGeigie World Tour | Print |
Blog - Misc
Written by Akiba   
Friday, 11 November 2011

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

 
'Hacker' Group Safecast Crowdsources Radiation Data in Japan | Print |
Blog - News
Written by Akiba   
Friday, 11 November 2011

FreakLabs is a proud member of Safecast and Tokyo Hackerspace and is an ardent believer in open, transparent data via open source sensor networks...and the safecast devices are using the Freakduino. yay! :)

Link



Link

 
Analog Devices Thermocouple Tutorial Videos | Print |
Blog - Misc
Written by Akiba   
Wednesday, 02 November 2011

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

 
Light Sequencing and Decoding DMX with an Arduino | Print |
Tutorials - Software
Written by Akiba   
Monday, 31 October 2011

It's been a while since I posted anything and that deserves another post just to talk about everything that happened in the last 8 months since the March earthquake and tsunami here in Japan. I'm a little bit tired of heavy topics and serious projects so I thought I'd put together a little something that's kind of fun and also timely. Now that we're moving into the holiday season, we're about to start seeing the hard core Christmas people setting up the elaborate light displays. The equipment to switch all the lighting channels and sequence everything is usually a bit costly but it doesn't have to be. If you're familiar with the Arduino environment and willing to put in a bit of elbow grease, blinging out your lawn is just a couple of mouse clicks away :)

I put this three part video tutorial together on how to use the Arduino platform to decode the DMX protocol. The DMX protocol is a standard protocol for stage lighting displays and it happens to be supported by a nice freeware light sequencer called Vixen. In the first part, I go over the DMX-512 protocol and the Arduino source code to decode it. In the second part, I show how to configure a lighting sequence with Vixen, some hardware implementations, and the whole system working together. And in the final part, I show how some simple changes to the code can enable you to control your lights wirelessly.

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Bob's Energy Vulture | Print |
Blog - Misc
Written by Akiba   
Saturday, 02 July 2011

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.

 

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Testing out the MPC2000 Gross Alpha/Beta Counter | Print |
Articles - Safecast
Written by Akiba   
Tuesday, 07 June 2011

It's been a while since I updated the blog. Things have been hectic recently and it's difficult to get a chunk of time together to write a proper post. I've decided however that I'll just start writing blog fragments to get back into the rhythm of updating the site again. I've recently been extremely busy with Safecast and Tokyo Hackerspace. Safecast is a volunteer group that is helping put together a radiation sensor network around Japan and the pace of movement is amazing. Tokyo Hackerspace is collaborating with Safecast on the project and between those two, consulting, and the shop, I'm surprised I have time to sleep. Anyways, this is a little slice of what I'm up to these days...

I just got back from Boston for the Safecast/MIT Media Lab trip and I'm completely jetlagged. Since I couldn't sleep, I though I'd try out my MPC2000 gross alpha/beta counter. This type of counter is used to check if a sample has any alpha or beta radiation content. Its good for checking air filters, food, water, and soil. The main reason you'd want something like this is because alpha and beta radiation is only harmful if ingested. Normally it can't penetrate skin so it won't do any damage outside the body. However once inside the body, it becomes toxic. So knowing whether there is any alpha/beta particles inside a sample that could potentially enter the body is useful. That's also why it's good for air/water/food/soil samples. I'd also like to start posting alpha and beta counts of food and water samples since I think that's one area that is a huge concern for the public in Japan at the moment.

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Hacking a Geiger Counter in Nuclear Tokyo | Print |
Blog - Misc
Written by Akiba   
Thursday, 24 March 2011

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.

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Geiger Experiments - Power Supply | Print |
Blog - Misc
Written by Akiba   
Monday, 21 March 2011

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:

Link

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. 

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Donations in Japan Needed | Print |
Blog - Misc
Written by Akiba   
Thursday, 17 March 2011

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
108-0071 

  • 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.

Akiba

 

 
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