Contactless cards are everywhere nowadays due to their ease to use and low price to produce. In addition, their reliability is excellent. That is why they are used in systems where security is essential within a low price. To develop the associated systems (cards, readers, terminals), efficient tools are needed. These tools can be a spy analyzing any communication or an emulator that can act and answer exactly as a real contactless card. The objective of this thesis was to develop a contactless card emulator on a product that is currently only spying, the NomadLAB of KEOLABS. The emulator feature is based on a discontinued product, the ProxiCARD, and it has for main objective to be compliant with the ISO 14443 standard. Through the analysis of its architecture and its current performance, I have developed a complete system that can be integrated into the ecosystem of the KEOLABS products. The features I developed take place into the source code of the NomadLAB, at the level of its ARM microcontroller in language C, and in its FPGA in language VHDL. The ARM is here to handle all the smart part of the transmission, while the FPGA to handle the coding and decoding process. In addition, I developed an antenna able to on one hand receive the signal from a reader and on the other hand to reply to it by modulating the magnetic field. I also developed and added my controls to the current computer software. Finally, I have written a lot of testing to make sure that this new system is reliable. The NomadLAB is now able to emulate a contactless card complying with ISO14443 standard, while keeping its spy features, and its control through a computer.