A solar weather display card!
The size is 12 cm by 6.5 cm and it has a little stand to stay up.
It's made with an ESP32 TTGO E-paper Board ( T5_V2.3_2.13 ), a little battery taken from an old vape and a little 5V 150ma solar panel.
The ESP32 check if the battery voltage is enough, connect to the wifi, get the weather data from OpenWeatherMap API, display it on the display and go to sleep for 15 min.
unlimited power ,so cool!