As I was getting ready to solder the radio chip (Si4012), I realized that the pin assignment for this chip was wrong. This is - obviously - not ideal. While the problem is easily fixable and the financial hit of ordering new boards is bearable (< 15 EUR), the additional delay (3-5 weeks) is quite severe.

However, there are still a few things I can do with the boards as they are now:

• check that programming the MCU works
• check the communication with the sensor
• check that the sensor works with the voltage the battery is able to supply