Safecast Onyx
Is there anything cooler than hacking the firmware of an Open Source Geiger counter? That’s right, it ranks pretty high. Well, this is what have been doing lately on the Safecast/Medcom Onyx!

A bit of history

On the 11th of March 2011, a magnitude 9 earthquake and tsunami hit Japan. A nuclear power plant was badly damaged, leading to one of the worst nuclear disasters on record.

Initial lack of transparency on the exact impact of this accident led a lot of people in Japan to launch private initiatives around environmental monitoring, in particular related to measurement of radioactivity. The Safecast organization was born.

The goal of Safecast has always been to gather data and disseminate it. They put together very simple logging Geiger counters for doing so, with tremendous success. The Geiger counters were mostly assembled from off the shelf breakout boards, they worked great, and they still do!

Meanwhile, in March 2012, Bunnie Huang of recent Novena fame – and more generally one of the most impressive hardware hackers alive today – decided to help out, and came up with a reference design for a very innovative Geiger counter. Traditionally, those devices have been very simple in terms of electronics, barely more than counters with sometimes a bit of logging capabilities. Bunnie’s initiative changed this completely, with a powerful CPU, a good screen and long term logging capabilities.

After Bunnie released his design – under an Open Source license -, Safecast worked with him and launched a Kickstarter campaign to fund a first production run. Naturally, I joined the campaign!

The Geiger counter was funded on the 19th of June 2012. A Californian company, International Medcom, was selected to manufacture it, and a few months later, I received my unit.

While this Geiger counter, nicknamed “Onyx” is a great piece of hardware, its firmware was a bit “bare bones” and did not take advantage of most of the possibilities of the platform. The good news is, since everything on this device is Open Source, there was nothing preventing me from contributing improvements!

My fork of the Onyx firmware can be found on github. Most of the contributions I wrote are now included in the official firmware.


Below are a few articles on the work I have done on the Onyx so far.