Check your Bitcoin addresses, show first unused address and calculate your balance.Check on GitHub!
Buy the hardware, flash the firmware and create configuration files on a micro sd.
When you will turn on the board, the configuration will be loaded and the board will connect to the WIFI. Using the explorer blockstream.info the board will retrieve information for each address. In the end will show the first unused address and balance.
Now you can turn off the board, the e.paper display will show you all this information without battery or USB attached. Or you can wait 60 seconds and the board will check another time all your addresses.
You will need an ESP32 module with a 2.13 e-paper display. You can find on AliExpress for around 15$.
Open pagami/pagami.ino with Arduino IDE, configure for ESP32 board, select port and flash the firmware.
You can configure your board using a microSD with textual files.