The goal was build something similar, but a little smaller and built from generally accessible parts.
Watch was equipped by BME280 atmospherical sensor. I can show you actual barometric pressrure, humidity and temperature. I also added an alimeter with settable reference point(pressure at sea level). It's presice enough to measure your own height. Temperature correction is also settable, becouse watch on wrist have little bit higher temperature.
Onboard are also a chronograph for measuring periods of time in accuracy of 0.01s.
Low power step up converter allows it to work from classic AAA battery or ni-mh.
LEDnode is operated by the incremental encoder with addidional back button and switch for mode select between ondemand(showing data by 5s after waking up) and force(show always).