i recently purchased a WeatherBoard, hoping to build a wired weatherstation with it, as there doesn't seem to be such thing to buy anymore..
now that i've got all parts at hand i wanted to start getting it set up with an arduino nano which eventually should pass the data to an openwrt device via a serial connection. but it seems i'm having issues with i2c with the nano and your provided software-stack (till now i just tested with a particle core and their libraries - which worked fine).
running the i2c-scanner on the nano does consistently find 3 devices on the bus (0x57 0x68 0x77).
but using SDL_Arduino_Weatherboard.ino i'm getting "BMP280 Not Present", only the RTC seems to be recognized..
though stated in multiple places of specs&docs that the I2C tolerates 3.3 AND 5V - the BMP280 seems to not work with 5V on JP4/VDD. i got suspicious when sometimes seeing values coming in once right after reset/reboot but after that the sensor seemed to have gone..