I thought of making a simple, inexpensive, compact, open-source radioactivity detector that could be placed in a plastic water pipe with plugs at both ends, attached to a stick, and then shuffled on the ground, scraped against rocks, lowered into water and so on. And with all this, do not have fear that "the body of the device will be scratched." For replacing the case with a new one costs cents. In the current implementation, one battery charge will be enough for about 2-4 months of continuous operation of the device, but with some minimal changes in the details of the circuit and using a slightly different firmware, it is possible to achieve a period of continuous operation of up to 1 - 1.5 years from a once charged battery. It takes 2 hours to charge the battery. Does anyone need it?