Lazy evening today, but what would you expect on Monday. I spent most of the time getting the ENC28J60 library to work on Arduino Due, and I succeeded in the end. One of the problems I met was the fact that Due fed from USB cable wasnt' able to provide enough power to the network chip. That was really strange, as the USB cable was connected to a powered hub, but whatever... after using a barrel jack with 12V, the network started to work. I had to do a few minor changes in the library itself, mostly sorting out of the small incompatibilities, like replacing "sei" with "interrupts" etc. The library is available from SVN, revision 154.
I changed the code for GM counter slightly to update the CPM more frequently, basically guessing the CPM based on 5 second measurement with a running average over 30 seconds, and I changed the display from mR/h to uR/h. The natural background shown is between 5-15 uR/h, which is more or less of what I'd expect. According to web, the natural background in Munich is around 0.8mSv/a, that's 80mR/a. Year has 8766 hour, thus we should expect to measure roughly 10uR/h.