Some Projects Are Better Seen, Not Heard — Like This Open Geiger Project Variant From @monksoffunkJP

Environmental monitoring is all the rage these days.

From indoor air quality metrics, using micro-fabricated, metal oxide chemristor sensors, etched in CMOS processes — such as the Bosch BME680 and its AI-enabled younger sibling, the BME688, or the Sensirion SGP40 VOC and SCD4x NDIR CO2, and even acoustic monitoring using tinyML edge compute nodes — we are all very, very aware of the parameters of the space that we all choose to occupy.

While environmental monitoring is indeed a hot topic, there is a specific subset of sensor within this category that focuses itself on the "hotter" parts of our environment... ☢

Watch out for the hot rocks!

While your average person might hope that they wouldn't ever have the use case for such a device, there is a certain morbid fascination associated with a Geiger counter.

Borrowing its name from the type of detector used inside (A Geiger-Müller detector tube), the Geiger counter style ionizing radiation meter has long been the mainstay of many a sci-fi/disaster film prop budget.

You can't mistake it's characteristic sound of a rapidly increasing repetition of "clicks," ramping up as the protagonist nears the mysterious, trefoil-emblazoned container in front of them.

Like I said, your average layperson should never really have a use for a Geiger counter — EPA react pretty strongly to nuclear waste being left around in public, and thankfully, the accident rate associated with nuclear power is almost negligible in comparison to the other main sources of power generation.

Despite that, the maker scene has jumped on the taskforce, and there is a great community all around the topic of instrumentation for sensing radioactivity! Barely have we just covered the RadSens dosimeter-radiometer, we're here again to hark at this equally well-designed Open Geiger Project variant from @monksoffunkJP.

The Open Geiger Project?

With a somewhat pricey bar to entry, most makers won't be rushing out to pick up a commercial, off-the-shelf GM tube detector.

Radiation is a problematic thing — it's invisible, and not something you want to be exposed to for any period of time. As a result, any commercially available detector will have a price tag that reflects it's safety-critical, guaranteed performance — it's designed to work, under any conditions it might see.

However, if you aren't doing first response at a radiological disaster site, the design spec can be relaxed a bit, and that's where the Open Geiger Project comes in!

Breaking the design of a GM detector down to the bare minimum, this nifty circuit uses the ever popular (and likely immortal) maker favorite, the Microchip ATmega328, to run the entire device — from driving and reading out the GM tube itself — to hosting a rather nifty UX by use of a monochrome LCD display, and three tactile switches.

With the vast majority of the components, from the aforementioned ATmega328 to the HV supply — formed of discrete components — required to drive the tube with the boosted voltage necessary for operation, this board will have you beeping along to beta rays in no time!

With a USB-C connector included for communications, the Open Geiger Project boards can also interface to an Android tablet or phone for data logging and real-time telemetry — a very handy feature to have when correlating readings from multiple detectors, both local and distributed!

Links

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