ESP32 + BME280 weather station with stephenson screen

thingiverse

### Outdoor Weather Station based on ESP32 and BME280 A compact outdoor weather station featuring an ESP32 module enclosed within a NodeMCU-compatible box that can be mounted to a rail or similar clamp (diameter 22mm). The design includes an arm to hold a stephenson screen, where a BME280 sensor is secured inside. Cables are routed through the arm, providing a clean and hidden installation. The assembly involves gluing all pieces together. For the sensor placement, the following sequence was used: bottom, vented, vented with BME holder, vented, top. However, this design has proven to be partially watertight, as rain can enter the ESP32 box. A better cover is recommended for a more reliable setup. Additionally, the stephenson screen appears to allow the sensor to heat up in direct sunlight. Future redesigns may address this issue by incorporating better shielding or active cooling mechanisms. ### UPDATE March 2019: The weather station has successfully endured a full cold and rainy season without any malfunctioning. The rain protection seems to be effective, although there were occasional hang-ups that required reboots. These issues are not attributed to the housing itself but rather to system hiccups also experienced on indoor boards. One notable observation is that when placed in direct sunlight, the station reads excessively high temperatures. Using an infrared thermometer, it was found that the housing temperature increases significantly. Two possible solutions to this issue are to install another sensor on the opposite side of the house and use the lower reading or to design a version with active airflow, such as a CPU fan. Unfortunately, there is no shaded area outside for testing purposes. To address this, an actively "cooled" version will be developed within the next few weeks. ### UPDATE June 2019: Instead of creating an actively cooled version, a new component has been added: sun protection. This feature is designed to match the latitude of Munich, Germany, ensuring that the stephenson screen remains shaded throughout the year. Users living closer to the equator may need to adjust the height accordingly. The cover is hollow on the circular part, allowing for printing in white PLA without overheating issues. For added light protection, aluminum foil can be used and pushed into place. A single layer of foil is sufficient, and it should be cut to width before insertion. This modification results in a slightly larger station but provides enhanced protection while maintaining vertical airflow.