This is simple device that can read RFID card, store in EEPROM and emulate it. Only support one card.

Parts needed:
- Arduino Pro Micro
- RMD6300

** Tested on EM410x cards
** Can store more cards

Code and scheme can be found here:
https://github.com/zosko/simple_rfid

For PCB design i will use services from SeeedFusion.

Seeed Fusion PCB Assembly Service offers one-stop prototyping for PCB manufacture, PCB assembly and as a result they produce superior quality PCBs and Fast Turnkey PCBA from 7 working days. When you prototype with Seeed Fusion, they can definitely provide Free DFA and Free functional tests for you! Check out their website to know about their manufacturing capabilities and service.

Link to Seeed Fusion Service within the sentence: https://www.seeedstudio.com/prototype-pcb-assembly.html