Initially I created a device with NodeMCU and prototyping board. See this wiki page for details about it.
Then I designed a PCB to make it smaller and better looking. See this wiki page for details about it.
I will try to design one with built-in charging circuit, micro USB port and CH340C chip so it will be possible to program it without any adapters, just like NodeMCU.
-reading / writing cards
-autosave of last card read to %Last_read% file (to prevent losing it if battery goes down before saving to file)
-saving / loading card data using internal memory
-file management (rename/delete/overwrite)
-device lock, button combination unlocking
Main menu -> Settings -> Lock -> Toggle
Main menu -> Settings -> Lock -> Set combination
Additional user interface features
-indicator in the bottom-right corner showing whether any rfid data is ready for writing (empty/card/some file)
-debugging of A0 (analog pin) input for buttons calibration
-display of board/memory/sketch/chip/sdk related data
Main menu -> Settings -> Debugging -> Buttons calibration view
Main menu -> Settings -> Debugging -> Info
Please let me know if you encounter any
-rfid
-ESP8266 OLED SSD1306
-LinkedList
The creators of libraries and boards/modules used in this project. RFID functionality is based on the RFID library created by Miguel Balboa and other contributors. When trying to implement menu I was relying on the esp8266_deauther project created by spacehuhn.