Geiger counters are basically just devices which enable us to measure ionizing radiation. In the context of human activity we have to deal with “natural” radiation sources and “artificial” ones. Some of the materials emitting ionizing radiation are used for medicinal purposes (Radiation-Therapy), as an additive in paint and even in smoke-detectors but the majority of it is used to create electricity in nuclear power plants and to stockpile thermonuclear weapons of mass destruction (well, except in iraq, as we all know), so many could get scared and a few could get rich.
Source and more detail with per site incident information on this mashup:
But how do we deal with something we cannot actually see, hear, feel, smell or taste? Exactly! We just don't think about it. We never perceive it as potentially dangerous to our health until an accident happens and we have to find someone with a geiger-counter, we have to trust, who can tell us how sunny the “weather” is? Better we do it ourselves, so that we can independently get all relevant realtime and historic metrics in a decentralized p2p system, with a far lower risk of getting tainted/biased/wrong/no data, especially when we as people really need it.
That should be in common rational awareness instead of ignorance or fear. Just like rain. We all know rain is neither good nor bad. It's just rain. And when we stay out too long in the rain without the appropriate protective clothing, we might get soaked so bad, that we might get sick. Our brain determines our maximum allowed in-rain time and the level of protective gear we need to repel the rain so we just visually perceive how many rain drops we see and how big they are. That gives us the freedom to decide whether to stay indoors or to wear some form of raincoat or just to risk it.
Unfortunately our body won't help us with detecting ionizing radiation (although it can suffer badly from it). Lost sources and depleted uranium shells, that irradiate uncontrolled and unnoticed, are as much a real problem as the Kyshtym Disaster and reactor incidents or catastrophic accidents like Chernobyl or Fukushima. Not to mention future generations, which will have to deal with the long term nuclear waste deposition. That's where geiger counters come back in: They let us “see” radiation levels and therefore give us the freedom to decide if and how we want to go on as safely as possible.
After the recent nuclear disaster at the Fukushima Daiichi nuclear power plant in Japan a lot of people started to realize the power of open, crowd-sourced radiation data and began to develop, build and buy geiger counters and geiger counter kits. Many share their local radiation levels through social networks and simple maps, like TDRM and SafeCast.
This would also be a great metric to collect for Argus and to display the data as an overlay in DSpace. Now imagine hundreds of these cheap solutions spread all over the world and sharing the metrics with one another to get a global Open Radiation Monitoring (ORM) network.
The Raspberry Pi is a perfect platform to be a cheap but very versatile geiger counter. It can be connected to a TV/Monitor to display a nice graphical interface, it can play the nostalgic tak, tak, taktaktak sound via audio output and it can also serve as an autonomous geiger counter sensor node (even solar powered) collecting and sharing real-time and historic data. All you need is:
The PiGI is designed & built as a simple open-source plug and play module for the Raspberry Pi to transform it into a cheap and hackable multi purpose geiger counter. It generates the necessary high voltage (up to 1000V) the GM tubes require to operate (typically 400-600V for beta/gamma GMTs).
Some pancake sensors (mostly used for alpha radiation) require an even higher voltage, theoretically the circuit should cover it. However, that's untested, only a LND712 (new, see picture) and two old Phillips tubes (Frieseke&Hoepfner FHZ74/76) could be tested, due to limited prototyping resources.
For every impulse the geiger tube registers the PiGI pulls a GPIO Pin of the Pi to ground (falling edge detection). On the Pi runs just a little daemon called counterd which waits for an interrupt to register the count and notify the display/audio/data-storage/network handler. That's why it can also easily be connected to any other embedded/micro controller system like:
HOWTOs can/will be provided, drop a comment if you need one for connections/pull-up configuration.
|Output Voltage||Up to 1000V|
|Current||<2mA @ ~0.09uSv/h local dose rate|
If you want to know more about the design or want to build one yourself, check out the PiGI Hardware Section for a detailed circuit description, schematics and printed circuit board layouts.
We've invested a couple of days into the new geiger counter software. Even though it is only in an early rough state it is already fun to work with. It's implemented as a full mobile-first HTML5/CSS3 Websocket based web application, than can be used in latest chromium & firefox browser. You can learn more about it in the software section
|2013-04-17||Basic circuit definitions|
|2013-04-23||Identified and ordered all parts|
|2013-04-28||Finished V1.0 Prototype Layout|
|2013-04-30||Ordered 7 prototype boards from MultiPCB|
|2013-05-05||Soldered first prototype|
|2013-05-13||Added dual-stack option (V1.1)|
|2013-05-19||Changed R1 from 3k9 to 1k to make T1 work more reliable|
|2013-05-22||Bumped prototype layout to V1.1 for production release|
|2013-05-23||Started long-term stability test|
|2013-06-17||Stopped long-term test for live-demo (stable/reliable 100% until now)|
|2013-06-17||2nd prototype board finished|
|2013-06-23||Updated + Added V1.0 board images|
|2013-08-04||Indiegogo.com campaign drafting has begun|
|2013-08-09||Selected CERN OHL 1.1 as licence for now|
|2014-02-08||Personal Log: PiGI Testing|
|2014-03-04||PiGI Software Hacking & Hackathon|
|2014-06-13||Generating Entropy From Radioactive Decay With PiGI|
|2014-06-28||More PiGI prototype boards finished|
|2014-10-15||Added PiGI Longterm Test Data to VFCC Dashboard (ORM Precursor)|
|2016-03-21||More PiGI PCBs available through small-scale crowdsourcing|
|2016-12-13||PiGI adopted & deployed @ https://tdrm.fiff.de/messtechnik.php|
|2016-12-19||Re-added missing C5 (330pf - 0805) to mouser BOM|
|2017-06-29||PiGI PCBs now available on pcbs.io|
|2017-12-18||Assembled PiGI boards available as a surplus TDRM production (Limited number)|
Public GIT Access:
Since the PiGI is ultimately cheap to produce once you reach the 1000 pieces boundary it would be great to put this out to the Pi-Community as a kit or even ready-to-go modules, the only thing that would need soldering is the tube itself (no SMT solderig). If you're interested in having one, please vote for the option you would like best so that we can determine how to structure a kickstarter/indygogo campaign that suits the community:
* These are the current sale price target estimations (excluding shipping), based on a worst cast scenario. As soon as there is a more solid count it is very easy to get the figures what it's really going to cost. The PCBs and part prices drop very much at 1000, 5000 and 10000 pieces breaking points.
Thank you for your time to state your interest. You might want to consider subscribing the Apollo-NG RSS Feed to get instant project update notifications. As this project is currently very dynamic in nature you are always welcome drop in on #apollo on freenode IRC for questions and discussions.